Introduction to Drafting and AutoCAD 2D

Introduction to Drafting and AutoCAD 2D

Wally Baumback

BCcampus

Victoria, B.C.

Contents

1

Accessibility Statement

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Accessibility of This Textbook

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In the mean time, we have done our best to be transparent about the existing accessibility barriers and features below:

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Let Us Know if You are Having Problems Accessing This Book

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The Accessibility Checklist table was adapted from one originally created by the Rebus Community and shared under a CC BY 4.0 License.

2

For Students: How to Access and Use this Textbook

This textbook is available in the following formats:

For more information about the accessibility of this textbook, see the Accessibility Statement.

You can access the online webbook and download any of the formats for free here: Introduction to Drafting and AutoCAD 2D. To download the book in a different format, look for the “Download this book” drop-down menu and select the file type you want.

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Tips for Using This Textbook

3

About BCcampus Open Education

The open publishing of Introduction to Drafting and AutoCAD 2D by Wally Baumback was funded by BCcampus Open Education.

BCcampus Open Education began in 2012 as the B.C. Open Textbook Project with the goal of making post-secondary education in British Columbia more accessible by reducing students’ costs through the use of open textbooks and other OER. BCcampus supports the post-secondary institutions of British Columbia as they adapt and evolve their teaching and learning practices to enable powerful learning opportunities for the students of B.C. BCcampus Open Education is funded by the British Columbia Ministry of Advanced Education and Skills Training and the Hewlett Foundation.

Open educational resources (OER) are teaching, learning, and research resources that, through permissions granted by the copyright holder, allow others to use, distribute, keep, or make changes to them. Our open textbooks are openly licensed using a Creative Commons licence and are offered in various book formats free of charge, or as printed books that are available at cost.

For more information about open education in British Columbia, please visit the BCcampus Open Education website. If you are an instructor who is using this book for a course, please fill out our Adoption of an Open Textbook form.

This book was produced using the following styles: AutoCAD 2D Style Sheet [Word file]

4

Introduction

Learning Outcomes

When you have completed this introduction, you will be able to:

  1. List the software and template files required to complete the AutoCAD 2D book.
  2. Describe this book’s philosophy and explain how to use the book to learn how to apply the AutoCAD commands and features to draw 2D drawings.
  3. Describe the conventions and symbols used in the AutoCAD 2D book.

Software Requirements

Operating System Software Required

This book was designed to be used on AutoCAD software that was designed for the Windows operating system.

AutoCAD Software Required

This book was written to be used with AutoCAD 2015, 2016, 2017, and 2018. You must have one of these software packages installed on your computer to complete the lab exercises in the
book.

Template Files Required for the AutoCAD 2D book

To complete the lab exercises in this book, you must have the four template files, that accompany it, on your hard drive. Module 2 will teach you how to use them.

About the Book

Philosophy of the AutoCAD 2D book

The AutoCAD 2D Self-paced book was written as a tool to guide and teach you to master AutoCAD. No two students learn at the same pace, therefore the book was written with competency-based modules. The competency-based modules are bite-size pieces that allow you to work at your own pace. They can be used to learn by distance education, correspondence, online, instructor-lead classes, or by individuals teaching themselves to use AutoCAD in their own home or office.

Scope of the AutoCAD books

There are five AutoCAD Self-paced books. They are AutoCAD 2D, AutoCAD 3D, AutoCAD 2D Advanced, AutoCAD 3D Advanced, and AutoLISP.

Suggested Prerequisites

To get the most from this book, it is suggested that you have a working knowledge of Windows operating system. At the very least, you must have the ability to create folders plus move, copy, rename, and delete files.

Book Structure and Components

The modules in the AutoCAD 2D book were written in a very logical step-by-step order. The following information will help you get the most from this book.

The Modules

The modules in the book were written as bite-size pieces in a precise order and contain the information that is required to learn AutoCAD 2D.

Do not skim through the modules. Read each page and ensure that everything is understood in each module. Do not jump around inside the module or from module to module. Work methodically through each module, page by page.

As you work your way through each module, try to understand all the information it contains. To ensure that it is understood, you must be able to complete the lab exercises to prove it. Only when everything in the module is understood and you can complete the lab exercises, in the specified time limit, should you go to the next module.

Each module may contain Must Know’s, User Tips, Workalongs, Lessons, Key Principles, and Lab Exercises.

Must Knows

Most modules contain user Must Knows. You must understand and retain each one of these principles as you work your way through the modules. If you cannot understand any one of them, read back through the module. Do not go on until you fully understand it. Here is an example:

(Do not attempt to understand this Must Know now. It is here as an example only.)

MUST KNOW: The Enter key or the Space bar are used to execute commands. If either one is pressed when there is no active command, AutoCAD will repeat the last command. Right clicking the mouse will produce the same results.

User Tips

User Tips are in the modules to help you draw in AutoCAD. They contain tips, tricks and ways to use commands that will help you draw faster and increase your productivity. Study them and try to use the tips while completing the labs exercises. They are there to help you work smarter, not harder. Here is an example:

(Do not attempt to learn this user tip now. It is here as an example only.)

USER TIP: The function key F3 toggles the AutoSnap feature off and on. Although there are other ways to do this, try to get into the habit of using F3 as it will greatly improve your drawing speed.

Workalongs

A Workalong is an exercise that you complete by working along with the module, tutorial style, to complete a drawing using AutoCAD. Completing the Workalongs will help you understand how the commands and features being taught in that module work by actually using them in AutoCAD. This will prepare you to complete the drawings in the lab exercises without any assistance.

(Do not attempt this workalong now, it is here for an example only.)

WORKALONG: Drawing Lines Using Cartesian Coordinates – Part 1

Step 1

Using the NEW command, start a new drawing using the template 2D English.

Step 2

Save and name the drawing AutoCAD 2D Workalong 04-1. Save it in the folder CAD Courses/AutoCAD 2D/Lab Exercises.

Step 3

Enter the LINE command, as shown below, to draw the object shown in the figure. Keep in mind that you enter what is in bold font, the author’s comments are in italics, and everything else are AutoCAD responses or prompts. (Figure Step 3)

Figure Step 3

Command: LINE

Specify first point: 1.75,4

(Always start with an absolute coordinate. It must be a X then a Y separated with a comma.)

Specify next point or [Undo]: @5,0

(Then change to relative coordinates. Note the @ first, then X and Y.)

Specify next point or [Undo]: @0,2

Specify next point or [Close/Undo]: @−2.5,0

Geometry and Drafting Lessons

Some modules contain drafting and/or geometry lessons. They are included to teach users who do not have any previous drafting/design knowledge or experience. They may also be handy for drafters or designers who need a refresher lesson.

If you already know and understand the theory in the lesson, you can skip it and go on to the next topic in the module. Knowing the theory taught in the lessons will help you complete the lab exercises.

(Do not attempt this geometry lesson now. It is here for an example only.)

Geometry Lesson: Circles

A circle is defined as a closed curve in which all points are the same distance from its center point. The center point is a single XY coordinate.

A circle is 360 degrees and can be divided into four quadrants. All points on a circle are at a given distance from is center point. The distance between any of the points and the center is called the radius.

Study the drawings in Figure 7-1, 7-2, 7-3, and 7-4 for a description of the geometry of a circle.

Figure 7-1 Geometry of a Circle – Part 1

Key Principles

Each module contains a list of Key Principles at the end. The Key Principles are principles that you should have learned and understand in that module. It is important that you fully understand each one as you will be required to use them in future AutoCAD work.

(Do not attempt to learn the key principles now. It is here for an example only.)

Key Principles in Module 4

1. The @ symbol means “The last absolute coordinate location,” or sometimes called the lastpoint.

2. To close the last line of a series of lines, enter either C (Close) or the absolute coordinate of the first.

3. To delete existing drawing objects, you can either use the ERASE command or the Delete key on the.

4. Objects can either be selected before or after a command is.

5. To unselect an drawing object, press the Esc Sometimes it has to be pressed twice.

Lab Exercises

All lab exercises have a time limit allocated to them. To complete the lab exercise in the specified time limit, you must be able to complete the drawing, check it for accuracy and make any corrections. If you cannot complete it in the time allowed, redo the entire lab exercise. It is your way of proving that you have mastered the module.

Almost all modules contain at least two lab exercises. It is strongly suggested that you complete all lab exercises in the module.

Checking the Accuracy of Your Drawings

Almost all lab exercises have a key provided that you can use to check the drawing’s accuracy. This is taught in Module 3: Checking the Accuracy of Your Drawings.

Competency Tests

Every fifth module is a timed competency test module. A Competency Test Module has multiple choice questions and a comprehensive lab exercise to test your mastery of the last set of modules completed. There is no key supplied with this module since it is meant to be checked by your instructor. If there are any parts of this module that you have trouble completing or cannot complete it in the time allowed, go back and reread the module or modules containing the information that you are having trouble with. If necessary, redo any lab exercises to help you learn the material.

Book Conventions and Symbols

The following conventions and symbols are used in the book to help you understand the material.

New Terms: Red Italics

Words in red italics are new terms being introduced in that module. They will only appear in red italics the first time they are appear and will be defined. Here is an example:

The current layer is the layer that AutoCAD will place all newly created drawing objects on.

Bolded Words and Numbers

In Workalongs, all words and numbers in bold font are input by the user. It is your way of knowing if it is your input or an AutoCAD response. Here is an example:

Command: LINE
Specify first point: 1.75,4
Specify next point or [Undo]: @5,0
Command:

AutoCAD Commands: Uppercase

AutoCAD commands are always in uppercase. Here is an example:

To construct a fillet, use the FILLET command. The rule of thumb to follow is, “If the arc you are drawing is tangent to both objects it is connecting to, use the FILLET command to insert it.”

Picking Objects or Locations on the Drawing

To help understand when an object or a location is picked, the modules use the letter “P” along with a number that indicates which pick it is in the sequence of picks.

(Do not attempt this workalong now. It is here as an example only.)

Command: FILLET
Current settings: Mode = TRIM, Radius = 0.6000
Select first object or [Polyline/Radius/Trim]: R
Specify fillet radius <0.6000>: .25
(Set the radius for the fillet.)
Select first object or [Polyline/Radius/Trim]: P1
Select second object: P2
(Pick the two lines to insert the fillet between.)
Command: FILLET
Current settings: Mode = TRIM, Radius = 0.2500
Select first object or [Polyline/Radius/Trim]: P3
Select second object: P4
Command:

Author’s Comments: Green, Italic Text and Green Textboxes

Comments by the author, to help explain what is happening in a command, are in green italics and enclosed in parentheses.

(Do not attempt these commands now. They are here for an example only.)

Specify first point: 1.75,4
(Always start with an absolute coordinate. It must be X then Y with a comma between them.)
Specify next point or [Undo]: @5,0
(Then change to relative coordinates. Note the @ first, then X and Y.)
Specify next point or [Undo]: @0,2
Specify next point or [Close/Undo]: @−2.5,0
(Note the negative coordinate since we are going in the negative X direction.)
Specify next point or [Close/Undo]: @0,1.5
Specify next point or [Close/Undo]: C
(You can use a C to close the last line and return to the first point.)
Command:

There are also author comments in the workalong or lab exercise to help you understand a principle or to complete a task. These will appear in a green textbox and be labelled “Author’s comments.” Here is an example:

AUTHOR’S COMMENTS: The Insertion scale for the all lab exercises in the AutoCAD 2D book are shown in the Units column as shown in the Figure 3-1.

Key Principles

Key Principles in Module Introduction 1

  1. To complete the lab exercises in this book, you must have the four template files, that accompany it, on your hard disk drive.
  2. Do not skim through the modules. Read and understand everything in each module. Do not jump around inside the module or from module to module. Work methodically through each module, page by page.
  3. The modules were written as competency-based bite-size pieces to allow you to work at your own pace and learn to use AutoCAD. Do not go onto the next module until you fully understood the module you are currently working on and have completed all lab exercises.
  4. All lab exercises have a time limit allocated to them. To complete a lab exercise in the specified time limit, you must be able to complete the drawing, check it for accuracy and make any corrections. If you cannot do this in the time allowed, redo the entire lab exercise. It is your way of proving that you mastered the module.

Do not memorize how to use AutoCAD – UNDERSTAND IT.

Have fun on your journey into the fascinating world of mastering AutoCAD.

Using AutoCAD is a never ending learning process and you will continue learning long after completing this book

5

Configure Your AutoCAD Software

Learning Outcomes

When you have completed this module, you will be able to:

  1. Configure your AutoCAD software for the AutoCAD 2D book.

IMPORTANT – PLEASE READ BEFORE COMPLETING THIS MODULE

If you are working on the AutoCAD 2D course in an instructor-led educational institute and only completing the workalongs and lab exercises on the computers at your school or college, skip this module. Go directly to Module 1.

If you are working on the AutoCAD 2D book in an instructor-led educational institute and completing the workalongs and lab exercises on your personal computer, do the following:

  1. Go to the BCcampus Open Education website and search for “AutoCAD 2D.” Download the Templates that are listed under “Supplementary Materials”
  2. After you download the templates, complete the remainder of this module to configure your personal AutoCAD software. Complete Steps 1 to 48 in the next Workalong. Do not start Module 1 until you completed all 48 steps.

This book was written to be used with AutoCAD running on a computer with Windows software.

WORKALONG: Configuring Your AutoCAD Software

Step 1

Start AutoCAD by clicking the desktop icon. In AutoCAD’s Graphic window, click the New icon located in the upper left corner. It will open the Select Template dialogue box (Figure Step 1).

Figure Step 1

Step 2

In the Select Template dialogue box, click the template file: acad.dwt (or just acad on some computers) to highlight it. Then click the Open button. This will display AutoCAD’s Graphic window. (Figure Step 2)

AUTHOR’S COMMENTS: Your dialogue box may not match the figure exactly.
Figure Step 2

Step 3

Disable all features on the Status bar by clicking any that display with a blue background as shown in Figure Step 3A. All features should display with a gray background as shown in Figure Step 3B. (Figure Step 3A and 3B)

 

Figure Step 3A
Figure Step 3B

Step 4

In the Command Line window, located on the bottom of the Graphic window, enter the OPTIONS command by typing it on your keyboard. This will open the Options dialogue box. (Figure Step 4)

Figure Step 4

Step 5

In the Options dialogue box, enable the Profiles tab. (Figure Step 5)

Figure Step 5

Step 6

Click the Add to List button. This will open the Add Profile dialogue box. Enter the name: Original for the Profile name. (Figure Step 6A and 6B)

Figure Step 6A
Figure Step 6B
AUTHOR’S COMMENTS: I am having you create a profile named Original so that you can go back to the way your AutoCAD was configured when you started this book. You will not be using this profile during the course, but at anytime (or when you complete the book) you can use this original profile to restore the original configuration.

Step 7

Using what you learned in Step 6, create a new profile named: AutoCADbook. (Figure Step 7)

Figure Step 7

Step 8

Click the AutoCADbook profile to highlight it. While it is selected, click the Set Current button. Ensure that the Current profile is AutoCADbook as shown across the top of the dialogue box. (Figure Step 8)

Figure Step 8

Step 9

Enable the display of the Files tab. Click the + on Customization Files to expand it. Click the + on the Main Customization File to expand it. Click the file and location to highlight it as shown in the figure. While it is selected, click the Remove button. (Figure Step 9)

Figure Step 9
AUTHOR’S COMMENTS: Your dialogue box may not match the figure exactly.

Step 10

Step 9 will remove the customization file and show a blank box as shown in the figure. Click the Browse button to open the Select a file dialogue box. (Figure Step 10A and 10B)

Figure Step 10A
Figure Step 10B

Step 11

In the Select a file dialogue box, pull down the Look in: box and find C drive. Click the folder: CAD Courses. (Figure Step 11)

Figure Step 11
AUTHOR’S COMMENTS: If you used a different drive when you downloaded the templates and menu from the website, you will have to find that drive letter instead of drive C.

Step 12

Under CAD Courses, click the folder: AutoCAD 2D. (Figure Step 12)

Figure Step 12

Step 13

Under the folder: AutoCAD 2D, click the folder: Menu. (Figure Step 13)

Figure Step 13

Step 14

In the folder: Menu, click the file: AutoCADbook.CUIX and then the Open box. (Figure Step 14)

Figure Step 14

Step 15

You should now see the file location:
C:\CAD Course\AutoCAD 2D\Menu\AutoCADbook.CUIX. (Figure Step 15A and 15B)

Figure Step 15A
Figure Step 15B

Step 16

Click the small arrow in the Workplace Switching icon on the right end of the Status bar located along the bottom of the Graphic window. (Figure Step 16)

Figure Step 16

Step 17

In the Workspace pull-up menu, click Workspace Settings. This will open the Workspace Settings dialogue box. (Figure Step 17)

Figure Step 17
AUTHOR’S COMMENTS: AutoCAD has two basic menu systems, Toolbars and Ribbons. You can switch back and forth between them. Along with using either the Toolbar or Ribbon menu, you should enable the Pull-down menu and use it in conjunction with either menu. The AutoCAD 2D book shows all three menus. I advise the beginner to use the Toolbar menus while working on the AutoCAD 2D book and then try the Ribbon menu after completing it. The AutoCAD 2D Advanced book teaches more about Toolbar, Ribbon, and Pull-down menus as well as how to create and edit them.
If you intend to use Toolbars menus to do this book, complete steps 18a and 19a. If you intend to use Ribbon menus to do this book, complete steps 18b and 19b.
AUTHOR’S COMMENTS: I suggest that you use Toolbar menus while working on this book.

Step 18a (Toolbar Menus)

In the Workspace Settings dialogue box, set My Workspace to: AutoCADbook. Enable Automatically save workspace changes by clicking the radio button. Click OK to close the box. (Figure Step 18a)

Figure Step 18a

Step 19a (Toolbar Menus)

Click the small arrow in the Workplace Switching icon again on the Status bar. Click the workspace: AutoCADbook to set it as the current workspace. Make sure that the check mark is beside the workspace: AutoCADbook as shown in the figure. (Figure Step 19a)

Figure Step 19a

Step 18b (Ribbon Menus)

If you intend to use Ribbon menus to do this book, complete Steps 18b and 19b. If you intend to use Toolbar menus to do this book, skip to Step 20.

In the Workspace Settings dialogue box, set My Workspace to the workspace: Drafting & Annotation. Enable Automatically save workspace changes by clicking the radio button. Click OK to close the box (Figure Step 18b)

Figure Step 18b

Step 19b (Ribbon Menus)

Click the small arrow in the Workplace Switching icon again on the Status bar. Click the workspace: Drafting & Annotation to set it as the current workspace. Make sure that the check mark is beside the workspace: Drafting & Annotation as shown in the figure. (Figure Step 19b)

Figure Step 19b

Step 20

Click the Hamburger icon located on the far right side of the Status bar. This will display the Customization menu. Enable or disable each item in the menu until it matches the figure. (Figure Step 20)

Figure Step 20

Step 21

AUTHOR’S COMMENTS: Enter the following commands in the Command Line window located along the bottom of the Graphic window.

Enter the MENUBAR command and set it to 1, as shown below.

Command: MENUBAR
Enter new value for MENUBAR <0>: 1
Command:

Step 22

Enter the NAVBARDISPLAY command and set it to 0, as shown below.

Command: NAVBARDISPLAY
Enter new value for NAVBARDISPLAY <1>: 0
Command:

Step 23

Enter the VPCONTROL command and set it to OFF, as shown below.

Command: VPCONTROL
Enter new value for VPCONTROL <ON>: OFF
Command:

Step 24 (2015)

If you are using AutoCAD 2015 execute the following command:

Enter the NEWTABMODE command and set it to 0, as shown below.

Command: NEWTABMODE
Enter new value for NEWTABMODE <1>: 0
Command:

Step 24 (2016-2017)

If you are using AutoCAD 2016 or 2017 execute the following command:

Enter the STARTMODE command and set it to 0, as shown below.

Command: STARTMODE
Enter new value for STARTMODE <1>: 0
Command:

Step 25

Click Tools in the Pull-down menu. In the Pull-down menu, click Options. (Figure Step 25)

Figure Step 25

Step 26

In the Options dialogue box, enable the Files tab. Expand Template Settings and Drawing Template File Location. Highlight the current location by clicking it. Click the Remove button. (Figure Step 26)

Figure Step 26

Step 27

It will display an empty box as shown in the figure. (Figure Step 27).

Figure Step 27

Step 28

Click the Browse button. In the Browse for Folders dialogue box, locate the folder: (Figure Step 28)

Figure Step 28

Step 29

Click OK and the new location will appear as shown in the figure. (Figure Step 29A and 29B)

Figure Step 29A
Figure Step 29B

Step 30

Enable the display of the Display tab. (Figure Step 30)

Figure Step 30

Step 31

In the Display resolution area, set the Arc and circle smoothness to 20000. (Figure Step 31)

Figure Step 31

Step 32

Set the Crosshair size to 100. (Figure Step 32)

Figure Step 32

Step 33

Click the Colors button to open the Drawing Window Color dialogue box. Highlight 2D model space, Uniform Background and then select the color White as shown in the figure. (Figure Step 33A and 33B)

Figure Step 33A
Figure Step 33B

Step 34

Click Apply and Close.

Step 35

Enable the User Preferences tab. (Figure Step 35)

Figure Step 35

Step 36

Ensure that both boxes are enabled in the Windows Standard Behavior area. Click the Right-click Customization button. Enable the box Turn on time sensitive right-click and set the Longer click duration to 250 milliseconds. (Figure Step 36A and 36B)

Figure Step 36A
Figure Step 36B

Step 37

Click Apply and Close.

Step 38

In the Insertion scale area, pull down the Source content units menu and select Inches. Do the same for the Target drawing units menu to set both to inches. (Figure Step 38A and 38B)

Figure 38A
Figure Step 38B

Step 39

Enable the Drafting tab. (Figure Step 39)

Figure Step 39

Step 40

Click the Colors box.  In the Color box, pull-down the list and  click Select Color.  Enable the Index Color tab in the Select Color dialogue box, enter the number 253 and click OK. (Figure Step 40A, 40B, and 40C)

Figure Step 40A
Figure Step 40B
Figure Step 40C

Step 41

Click OK and then click Apply and Close.

Step 42

Set the AutoSNAP Marker Size and the Aperture Size to approximately the sizes shown in the figures.  If required, you can adjust these sizes, when required, as you work your way  through the book. (Figure Step 42)

Figure Step 42

Step 43

Enable the 3D Modeling tab.  (Figure Step  43)

Figure Step 43

Step 44

In the Display Tools in Viewport area, set it as shown in the figure. (Figure Step 44)

Figure Step 44

Step 45

Enable the Selection tab. (Figure Step 45)

Figure Step 45

Step 46

Set the Pickbox Size and the Grip Size to approximately the sizes as shown in the figure. If required, you can adjust these sizes, when required, as you work your way through the book. (Figure Step 46)

Figure Step 46

Step 47

Click the OK button on the bottom of the Options dialogue box to close it.

Step 48

Your AutoCAD software is now configured for the AutoCAD 2D book. Your Graphic window should closely match the figure. (Figure Step 48)

Figure Step 48

Step 49

Go to Module 1.

I

Part 1

1

Module 1: AutoCAD’s User Interface

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe and configure AutoCAD’s interface including the Graphic window, crosshairs, Graphic cursor, pickbox, Status bar, Model and Layout tabs, Pull-down menu, Toolbar menus, Ribbon menus, dialogue boxes, windows, using of the mouse, Command Line window, and the Text window.
  2. List and describe the two basic AutoCAD menus systems; Toolbars and Ribbons.

AutoCAD’s Graphic Window

AutoCAD’s Graphic window is shown in Figure 1-1. The Graphic window is used most of the time when you are working in AutoCAD.

Figure 1-1

Crosshairs and Graphic Cursor

The crosshairs indicates your current location on the Graphic window or in 2D space. If you were drawing by hand, think of it as the point of your pencil. It is one of AutoCAD’s most important features and is used extensively when you are creating drawings. See Figure 1-1, and 1-3.

When you move the crosshairs onto a menu item, it will change its display to the Graphic cursor as shown in Figure 1-2. You use it to select menu items.

Figure 1-2

Pickbox

The pickbox is a small square located at the intersection of the crosshairs as shown in Figure 1-3. It is used to pick drawing objects.

Figure 1-3

Status Bar

The Status bar, Figure 1-4, is positioned across the bottom of the Graphic window and becomes a very important part of your day-to-day AutoCAD work.

Figure 1-4

The coordinate location or the XYZ coordinates of the current location of the crosshairs is displayed near the center of the Status bar. The coordinate location display can be enabled or disabled by clicking it with the left mouse button. Toggle buttons for AutoCAD’s features are located immediately to the right of the coordinate display. Many of these features will be taught in the AutoCAD 2D book.

Model and Layout Tabs

The Model and Layout tabs, Figure 1-5, are used to toggle the display of Model space or one of the layouts. This will be discussed in greater detail in Module 18.

Figure 1-5
USER TIP: The size of the crosshairs can be changed. For the AutoCAD 2D book and most other AutoCAD work, it is best to have them full screen as shown in Figure 1-1.

AutoCAD’s Menu Systems

AUTHOR’S COMMENTS: AutoCAD has two basic menu systems, Toolbars and Ribbons. You can switch back and forth between them. Along with using either the Toolbar or Ribbon menu, you should enable the Pull-down menu and use it in conjunction with either menu. The AutoCAD 2D book shows all three menus. I advise the beginner to use the Toolbar menus while working on the AutoCAD 2D book and then try the Ribbon menu after completing it.

AutoCAD has two different menu systems that allows you to communicate with it. The two menu systems that you can choose from are the Toolbar menus and the Ribbon menus. See Figure 1-6. You can and should add the Pull-down menu to either the Toolbar or the Ribbon menu.

Figure 1-6a The Toolbar Menus
Figure 1-6b The Ribbon Menus

Pull-down Menus

The Pull-down menus are located across the top of the Graphic window. When you click one of the items on the menu, with the left mouse button, the menu will pull down as shown in Figure 1-7 and 1-8.

Figure 1-7 Pull-Down Menu
Figure 1-8 AutoCAD’s Pull-down and Toolbar Menus

A Pull-down Menu Flyout

If an item on the Pull-down menu has a small solid triangle at the end, it has a Flyout menu associated with it. Place the Graphic cursor on the triangle to force the Flyout menu to display as shown in Figure 1-9.

Figure 1-9 Flyout Menu

Toolbar Menus

Toolbar menus are a series of icons that are located on a collection of menu bars. See Figure 1-10. The display of each toolbar can be enabled or disabled at your discretion. If they were all displayed at the same time, they would virtually fill the Graphic window. Therefore, their display must be enabled or disabled, as required, by the current operation in the drawing.

Toolbars can float inside the Graphic window or they can be docked along any one of its four sides. If the Graphic cursor is placed on an icon in a toolbar, a tooltip will display indicating the purpose of the icon as shown in Figure 1-11. AutoCAD allows you to create or edit existing toolbar menus. This is taught in the AutoCAD 2D Advanced book.

Figure 1-10 An AutoCAD Toolbar

 

Figure 1-11 A Toolbar Menu – Showing a Tooltip

Docked and Floating Toolbar Menus

In Figure 1-8, the toolbars across the top of the Graphic window are docked and the ones in the centre are floating.

Displaying Toolbar Menus

To enable or disable the display of a toolbar menu, place the Graphic cursor on any icon on a currently displayed toolbar and right-click the mouse. A list of all the available toolbar menus will display as shown in Figure 1-12. Click the name on the toolbar menu to toggle its display. A checkmark beside the toolbar’s name indicates that it is currently displayed in the Graphic window.

Figure 1-12 Toolbar Menu Pull-down

Dialogue Boxes and Windows

When a menu item has 3 dots after it as shown in Figure 1-13 it indicates that there is more. When clicked, it will open a dialogue box or a window.

Figure 1-13 Pull Down Menu – More

Dialogue Boxes

AutoCAD uses many different dialogue boxes to speed the drawing process. A dialogue box is an effective and efficient method for AutoCAD to allow you to modify or enter information, settings, and sizes. While a dialogue box is open, no other work can be done in the current drawing. It must be closed before continuing to the next command. If you close a dialogue box by clicking the X in the top right corner, it will cancel your current input in the box. If you want to save your input, you must click the OK button. A typical dialogue box is shown in Figure 1-14.

Figure 1-14 A Dialogue Box

Windows

AutoCAD uses many different windows to speed the drawing process. Compared to a dialogue box, a window is a more efficient method for AutoCAD and you to communicate. Windows are interactive and display data and information about the current drawing or objects in that drawing as the drawing is being worked on. Unlike a dialogue box, a window updates automatically and can remain on the screen as you work on the drawing. You must close a window by clicking the X in the upper corner. This will not cancel you input. A typical window is shown in Figure 1-15.

Figure 1-15 AutoCAD’s Property Window

Command Line Window

 

The Command Line window is used, by you, to enter keyboard commands and user inputs. It is also used by AutoCAD to output information to you. See Figure 1-16. It is one of the ways that you communicate with AutoCAD and is a very important way for AutoCAD to communicate with you. It is important for you to watch this window closely when you are drawing. It is used by AutoCAD to ask for information, instruct you to what data it requires, or display answers to your inquiries. This will be discussed in much greater detail in Module 2.

Figure 1-16 Command Line Window

Text Window

The Text window, Figure 1-17, displays all of the commands that were entered by you and AutoCAD’s responses to those command for the duration that the current drawing is open. This is one way for you to look back at the commands, user input, and AutoCAD’s responses. To toggle the display of the Text window, press F2.

Figure 1-17 AutoCAD’s Text Window

The Mouse

AutoCAD is programed to use the three buttons on a mouse as follows:

Left Button: This is the pick button. Use it to pick objects, pick menu items, or to select locations on the drawing.

Middle Button: The middle button, or wheel, is used to zoom and pan around the drawing. This will be discussed in detail in Module 9.

Right Button: The right button has two uses. If pressed and released quickly, it repeats the last command. If pressed and held in, it displays the cursor menu. See Figure 1-18.

Figure 1-18 Cursor Menu for the FILLET Command

The cursor menu displays differently depending on the current or last command entered. It can be a very helpful menu once you become a more experienced user.

 

WORKALONG: Learning to Use AutoCAD’s Interface Using Toolbar Menus

If you are using Ribbon menus, skip forward to WORKALONG: Learning to Use AutoCAD’s Interface using Ribbon Menus.

Step 1

Launch AutoCAD. AutoCAD’s blank window will display. (Figure Step 1)

Figure Step 1

AUTHOR’S COMMENTS: The blank window displays grey when there is no active drawing. Your window should closely match the figure.

Step 2

Click the New icon located in the upper right corner as shown in the figure. This will open the Select Template dialogue box. (Figure Step 2)

Figure Step 2

Step 3

In the Select Template dialogue box, click the template file: 2D English to highlight it. Then click the Open button. This will open AutoCAD’s Graphic window. (Figure Step 3)

Figure Step 3

AUTHOR’S COMMENTS: The four templates are part of the AutoCAD 2D book and must be used to complete all workalongs and lab exercises. If you do NOT see the four templates files shown in Figure Step 3, you must go back and redo module Introduction 2. If you only see the name and not the .dwt extension, that is OK. Do not continue in this module until your dialogue box shows the four templates. If you have trouble getting it to match and have an instructor, email him/her for help.

Step 4

Click the small arrow in the Workplace Switching icon again on the Status bar. Click the workspace: AutoCADbook to set it as the current workspace. Make sure that the check mark is beside AutoCADbook as shown in the figure. Your Graphic window should match the figure. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 4B

AUTHOR’S COMMENTS: Your Graphic window should closely match the figure.

Step 5

Check to ensure that the Model tab is enabled. It is located on the bottom left corner of the window. If it is not enabled, click it with the left mouse button. (Figure Step 5)

Figure Step 5

AUTHOR’S COMMENTS: The Model tab should be enabled at all times, while working on workalongs and lab exercises in the AutoCAD 2D book, unless you are instructed otherwise. Module 18 will teach you how work in the Layout tabs.

 

Step 6

Disable all features on the Status bar by clicking any that display with a blue background as shown in Figure Step 6A. All features should display with a gray background as shown in Figure Step 6B. (Figure Step 6A and 6B)

Figure Step 6A
Figure Step 6B

AUTHOR’S COMMENTS: Important Unless otherwise instructed, each time you start a workalong or lab exercise while working on the AutoCAD 2D book, all features on the Status bar should be disabled as shown in Figure Step 6B.

Step 7

Click the coordinate display, located on the left side of the Status bar, to disable it shown in Figure Step 7A. Click it again to enable it as shown in Figure Step 7B. (Figure Step 7A and 7B)

Figure Step 7A
Figure Step 7B

AUTHOR’S COMMENTS: The coordinate display should be enabled while working in AutoCAD. While it is not used very much in day-to-day drawing, it can be very handy at times.

USER TIP: You can easily check to see if a feature on the Status bar is enabled or disabled by holding your graphic cursor on the icon. A pop up window will display indicating the name of the feature and whether it is currently on or off as shown in the figures.

Step 8

Click the Draw item in the Pull-down menu to pull down the menu. Hold the Graphic cursor over the flyout triangle at the end of the Circle command to force the flyout to display. (Figure Step 8)

Figure Step 8

Step 9

Move the Graphic cursor onto any toolbar icon and right click the mouse. This will pull down a list of all available toolbar menus. The ones that are preceded with a checkmark are enabled and are currently displayed in the Graphic window. Ensure that the toolbars Draw, Inquiry, Layers, Modify, Properties, Standard, and Styles are the only ones enabled. Click on the name to toggle the display of the toolbar. (Figure Step 9)

Figure Step 9

Step 10

Move the Graphic cursor onto the lines at the end of the Layers toolbar. Press and hold the left mouse button down and drag the toolbar somewhere into the Graphic window and release the button. (Figure Step 10A, 10B, and 10C)

Figure Step 10A
Figure Step 10B
Figure Step 10C
AUTHOR’S COMMENTS: This step may be a little tricky the first few tries. Practice it until you can do it easily.

Step 11

Move the cursor onto bars at the end of the Layers toolbar and hold it for a few seconds. The toolbar’s name, Layers, will display as a tooltip. (Figure Step 11)

Figure Step 11

Step 12

Using what was taught in Step 9, drag all six toolbars into the Graphic window as shown in the figure. (Figure Step 12A and 12B)

Figure Step 12A
Figure Step 12B

Step 13

Using what you learned doing Steps 9 and 12, drag all six toolbars back into position by docking them to the locations shown in the figure. (Figure Step 13)

Figure Step 13
AUTHOR’S COMMENTS: Dragging and docking the toolbar can be a little tricky at first. Practice it until it is easy for you to do. The six toolbars are now all docked.

Step 14

Using what you learned earlier in the workalong, enable the display of the Modify II toolbar. It will display as a floating toolbar. (Figure Step 14A and 14B)

Figure Step 14A
Figure Step 14B

Step 15

Move the Graphic cursor onto the top edge of the Modify II toolbar until the cursor displays as double arrows. See Figure Step 15A. Press the left mouse button and while holding it down, drag the toolbar upwards until it matches Figure Step 15C. (Figure Step 15 A, 15B, 15C)

Figure Step 15A
Figure Step 15B
Figure Step 15C
AUTHOR’S COMMENTS: Changing the shape of a toolbar can be a little tricky at first. Practice it until it is easy for you to do.

Step 16

Using what was taught in Step 14 and 15, enable the display of the Object Snap toolbar and change its appearance to match the figure. (Figure Step 16)

Figure Step 16

Step 17

Close the Object Snap and Modify II toolbars by clicking the X in the top right corner of each toolbar.

AUTHOR’S COMMENTS: As you can see, toolbars can easily be displayed, have there shape changed, or moved around the Graphic window as needed. You can enable their display, when required, in the drawing process and closed them when the process is completed. While working on the AutoCAD 2D book, leave the 6 toolbar displayed and docked at all times as shown in Figure Step 13.

Step 18

Click Format on the Pull-down menu and then click Units to open the Drawing Units dialogue box. Click OK to close the dialogue box. (Figure Step 18A and 18B)

Figure Step 18A
Figure Step 18B

AUTHOR’S COMMENTS: Always close a dialogue box using the OK or the Cancel button. If you close it by clicking the X in the top right corner, you are cancelling all changes that you made while the box was open. If you want to cancel the changes, click the Cancel button to close the dialogue box. When you click OK, you are closing it and saving all the changes you made.

Step 19

Move the Graphic cursor onto the icons in the Standard toolbar. As you move it over the icons, tooltips with the toolbar’s name will display. Find the Properties icon. Click it to open the Properties window. (Figure Step 19A and 19B)

Figure Step 19A
Figure Step 19B

Step 20

Click the X in the top corner of the window to close it.

AUTHOR’S COMMENTS: Windows are different than dialogue box as they are interactive. Any changes made, while they are open, are saved immediately. That makes it OK to close them by clicking the X.

Step 21

Press the function key F2. It will open the Text window as shown in the figure. (Figure Step 21)

Figure Step 21
AUTHOR’S COMMENTS: Your Text window may not match the figure exactly.

Step 22

Press the function key F2 again to close the Text window.

Step 23

Click File on the Pull-down menu. Click Exit to close AutoCAD. If you are asked if you want to save the drawing, click No. (Figure Step 23)

Figure Step 23

Step 24

Go to Module 2.

WORKALONG: Learning to Use AutoCAD’s Interface using Ribbon Menus

If you are using Toolbar menus, go to Module 2.

Step 1

Launch AutoCAD. AutoCAD’s blank window will display. (Figure Step 1)

Figure Step 1
AUTHOR’S COMMENTS: The blank window displays grey when there is no active drawing. Your window should closely match the figure.

Step 2

Click the New icon located in the upper right corner as shown in the figure. This will open the Select Template dialogue box. (Figure Step 2)

Figure Step 2

Step 3

In the Select Template dialogue box, click the template file: 2D English to highlight it. Then click the Open button. This will open AutoCAD’s Graphic window. (Figure Step 3)

Figure Step 3
AUTHOR’S COMMENTS: The four templates are part of the AutoCAD 2D book and must be used to complete all workalongs and lab exercises. If you do NOT see the four templates files shown in Figure Step 3, you must go back and redo module Introduction 2. If you only see the name and not the .dwt extension, that is OK. Do not continue in this module until your dialogue box shows the four templates. If you have trouble getting it to match and have an instructor, email him/her for help.

Step 4

Click the small arrow in the Workplace Switching icon again on the Status bar. Click the workspace:

Drafting & Annotation to set it as the current workspace. Make sure that the check mark is beside Drafting & Annotation as shown in the figure. Your Graphic window should closely match the figure. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 4B
AUTHOR’S COMMENTS: Your Graphic window should closely match the figure.

Step 5

Check to ensure that the Model tab is enabled. It is located on the bottom left corner of the window. If it is not enabled, click it with the left mouse button. (Figure Step 5)

Figure Step 5
AUTHOR’S COMMENTS: The Model tab should be enabled at all times, while working on workalongs and lab exercises in the AutoCAD 2D book, unless you are instructed otherwise. Module 18 will teach you how work in the Layout tabs.

Step 6

Disable all features on the Status bar by clicking any that display with a blue background as shown in Figure Step 6A. All features should display with a gray background as shown in Figure Step 6B. (Figure Step 6A and 6B)

Figure Step 6A
Figure Step 6B
AUTHOR’S COMMENTS: Important. Unless otherwise instructed, each time you start a workalong or lab exercise while working on the AutoCAD 2D book all features on the Status bar should be disabled as shown in Figure Step 6B.

Step 7

Click the coordinate display, located on the left side of the Status bar, to disable it shown in Figure Step 7A. Click it again to enable it as shown in Figure Step 7B. (Figure Step 7A and 7B)

Figure Step 7A
Figure Step 7B
AUTHOR’S COMMENTS: The coordinate display should be enabled while working in AutoCAD. While it is not used very much in day-to-day drawing, it can be very handy at times.

USER TIP: You can easily check to see if a feature on the Status bar is enabled or disabled by holding your graphic cursor on the icon. A pop up window will display indicating the name of the feature and whether it is currently on or off as shown in the figures.

Step 8

Click Format on the Pull-down menu and then click Units to open the Drawing Units dialogue box. Click OK to close the dialogue box. (Figure Step 8A and 8B)

Figure Step 8A
Figure Step 8B
AUTHOR’S COMMENTS: Always close a dialogue box using the OK or the Cancel button. If you close it by clicking the X in the top right corner, you are cancelling all changes that you made while the box was open. If you want to cancel the changes, click the Cancel button to close the dialogue box. When you click OK, you are closing it and saving all the changes you made.

Step 9

Click the View tab on the Ribbon menu. Find the Properties icon. Click it to open the Properties window. (Figure Step 9A and 9B)

Figure Step 9A
Figure Step 9B

Step 10

Click the X in the top corner of the window to close it.

AUTHOR’S COMMENTS: Windows are different than dialogue box as they are interactive. Any changes made, while they are open, are saved immediately. That makes it OK to close them by clicking the X.

Step 11

Press the function key F2. It will open the Text window as shown in the figure. (Figure Step 11)

Figure Step 11

Step 12

Press the function key F2 again to close the Text window.

Step 13

Click File on the Pull-down menu. Click Exit to close AutoCAD. If you are asked if you want to save the drawing, click No. (Figure Step 13)

Figure Step 13

Step 14

Go to Module 2.

Key Principles

Key Principles in Module 1

  1. The Graphic window is used most of the time when working in AutoCAD.
  2. The crosshairs indicates your current location. Think of it as the point of the pencil. It is used extensively while working in AutoCAD. It is one of the most important tools.
  3. The pickbox is a small square located at the intersection of the crosshairs.
  4. The Status bar is positioned across the bottom of the Graphic window and becomes a very important part of your day-to-day AutoCAD work.
  5. The Model and Layout tabs are used to enable the display of the model or a layout.
  6. The Command Line window is used to enter keyboard commands and user inputs. It is also used by AutoCAD to output information to you.
  7. The Pull-down menu Is located across the top of the Graphic window. If an item on the Pulldown menu has a small solid triangle at the end, it has a flyout menu associated with it.
  8. The toolbar menus are a series of icons that are located on a collection of menu bars.
  9. AutoCAD uses many different dialogue boxes to speed the drawing process. A dialogue box is an effective and efficient method for AutoCAD to allow you to modify or enter information, settings, and sizes.
  10. AutoCAD uses many different windows to speed the drawing process. Compared to a dialogue box, a window is a more efficient method for AutoCAD and you to communicate.
  11. AutoCAD is programed to use the three buttons on a mouse. The left button is the pick button.
  12. AutoCAD’s Text window displays all of the commands that were entered by you and AutoCAD’s responses to those command for the duration that the current drawing is open. To toggle the display of the Text window, press F2.

2

Module 2: Getting Started

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe a drawing, a drawing template, drawing names, and drawing file extensions.
  2. Apply the NEW, QSAVE, OPEN, SAVEAS, and CLOSE commands to start a new drawing, name and save the current drawing into a specified folder, open a filed drawing, save the current drawing with a different name, and close the current drawing.
  3. Describe AutoCAD commands, option prompts, and defaults.
  4. Describe how to execute, repeat, and abort commands.
  5. Describe how the Space, Enter, and Esc keyboard keys are used in AutoCAD.

An AutoCAD Drawing

An AutoCAD drawing is a database file containing graphical and non-graphical data. The file must have the extension .dwg. To be able to draw anything in AutoCAD, you must have an open drawing. Multiple drawings can be opened at the same time and you can switch between them, as required. Only one drawing can be current at a time. Thecurrent drawing is the drawing currently being affected by the commands you are entering. It is also called theactive drawing.

Drawing Templates

Adrawing template is a drawing file that may contain layouts, defaults, blocks, and standards set by the creator of the template. A template file must be used to start every new drawing. A template drawing is simply an AutoCAD drawing saved as a template file and must have the extension .dwt. Creating template files is taught in the AutoCAD 2D Advanced book.

Drawing Templates for the AutoCAD 2D book

There are four drawing template files that are an important part of the AutoCAD 2D book. One of these templates must be used to start all new drawings for all workalongs and lab exercise throughout the book. These templates are supplied to each user of the AutoCAD 2D book and should be saved in the Templates folder as shown in Figure 2-1.

Figure 2-1
AutoCAD 2D book Templates

AutoCAD File Extensions

AutoCAD uses many different file extension names. The file extensions used in the AutoCAD 2D book are .dwg, .dwt, and .bak. See Figure 2-2. Many other AutoCAD file extensions are taught in the AutoCAD 2D Advanced book.

AutoCAD creates a .bak file when a previously saved drawing is saved. When the current drawing is saved, AutoCAD changes the extension of the existing drawing from .dwg to .bak and then creates a new file with the extension .dwg. If a drawing file ever gets lost or corrupted, the extension name of the .bak file can be changed to .dwg and opened in AutoCAD.

Figure 2-2 AutoCAD File Extension Names

The Drawing Name

Each drawing should be assigned a unique name. It is important for you to name a new drawing as soon as possible after you start it. Getting into a habit of doing this will save you many hours of searching the disk drive looking for existing drawings or redrawing lost drawings.

AutoCAD Command: NEW

The NEW command is used to start a new drawing. Shortcut: CNTL+N

AutoCAD Command: QSAVE

The QSAVE command is used to save the current drawing. Shortcut: CTRL+S

 

AutoCAD Command: OPEN

The OPEN command is used to open a saved drawing. Shortcut: CTRL+O

AutoCAD Command: SAVEAS

The SAVEAS command is used to save the current drawing with a new name. Shortcut: CTRL+SHIFT+S

AutoCAD Command: CLOSE

The CLOSE command is used to close the current drawing. Shortcut: none

MUST KNOW: When you save a drawing for the first time, AutoCAD adds the extension .dwg to the drawing’s name. When you save a drawing that was previously saved, AutoCAD changes the extension of the existing drawing file to .bak and creates a new drawing file with the extension .dwg. If a drawing file ever gets lost or corrupted, the extension name of the .bak file can be changed to .dwg and opened in AutoCAD.

WORKALONG: Creating, Naming, Saving, Opening, and Closing Drawings

Step 1

Launch AutoCAD.

Step 2

Click the New icon. This will open the Select template dialogue box. Select the template: 2D English and then click Open (Figure Step 2)

Figure Step 2
AUTHOR’S COMMENTS: If you do NOT see the four templates files shown in Figure Step 2, you must go back and redo module Introduction 2. If you only see the name and not the .dwt extension, that is OK. Do not continue in this module until your dialogue box shows the four template shown in Figure Step 2 with or without the extension. If you have trouble getting it to match and have an instructor, email him/her for help.

Step 3

Note the drawing name: Drawing1.dwg displays on the top bar of the Graphic window. (Figure Step 3)

Figure Step 3
AUTHOR’S COMMENTS: AutoCAD automatically assigns this name.

Step 4

Enter the QSAVE command to open the Save Drawing As dialogue box. Find and select the folder: CAD Courses. Under it, select the folder: AutoCAD 2D and under that, the folder: Lab Exercise. (Figure Step 4A, 4B, and 4C)

Figure Step 4A
Figure Step 4B
Figure Step 4C

Step 5

With Lab Exercises in the Save in box, enter the name: AutoCAD 2D Workalong 02-1 in the File name: box. (Figure Step 5)

Figure Step 5

AUTHOR’S COMMENTS: I recommend that you save and name a new drawing immediately after you start it and then save it every 15 minutes after that. If there is a power failure or your computer freezes, the maximum amount of drawing time you can lose is 15 minutes. The first time you save your drawing, you will be asked to assign a name. Once it is named, you can save it quickly with the QSAVE command.

Step 6

Note that the folder location and the drawing name:

C:\CAD Courses\AutoCAD 2D\Lab Exercises\AutoCAD 2D Workalong 02-1.dwg displays on the top bar of the Graphic window. (Figure Step 6)

Figure Step 6

Step 7

Check to ensure that the Model tab is enabled. If not, enable it by clicking it with the left mouse button. (Figure Step 7)

Figure Step 7
AUTHOR’S COMMENTS: Until you are instructed otherwise, the Model tab should be enabled at all times while working on workalongs and lab exercises in the AutoCAD 2D book. Module 18 will teach you how to work in the layouts.

Step 8

Disable all features on the Status bar by clicking any that are enabled. Your Status bar should match the figure. (Figure Step 8)

Figure Step 8

Step 9

Ensure that ByLayer is enabled in the first 3 boxes on the Properties toolbar or the Properties tab in the Ribbon menu. (Figure Step 9)

Ribbon Menu
Figure Step 9 Toolbar Menu
AUTHOR’S COMMENTS: Important Unless otherwise instructed, each time you start a workalong or a lab exercise while working on the AutoCAD 2D book, the Model tab should be enabled, all features on the Status bar should be disabled, and ByLayer should be enabled in the first three boxes on the Properties toolbar or Ribbon menu.

Step 10

Enter the CLOSE command to close the current drawing. If you are asked if you want to save the drawing, answer Yes.

Step 11

Using what you learned in the first part of the workalong, start a new drawing using the template: 2D Metric. (Figure Step 11)

Figure Step 11

Step 12

Save and name the drawing: AutoCAD 2D Workalong 02-2 in the folder: C:\CAD Courses\AutoCAD 2D\Lab Exercises. (Figure Step 12)

Figure Step 12

Step 13

Enter the CLOSE command to close the current drawing. If you are asked if you want to save the drawing, answer Yes.

Step 14

Enter the OPEN command to open the Select File dialogue box. In it, locate the folder: C:\CAD Courses\AutoCAD 2D\Lab Exercises. (Figure Step 14)

Figure Step 14

Step 15

With Lab Exercise in the Look in box, select the drawing: AutoCAD 2D Workalong 02-1. (Figure Step 15)

Figure Step 15

USER TIP: If the Select File dialogue box does not open when you enter the NEW command, enter the FILEDIA command and set the value to 1 as shown below:

Command: FILEDIA

Enter new value for FILEDIA <0>: 1

Command:

Step 16

Enter the SAVEAS command. It will open the Save Drawing As dialogue box. In the File name: box, enter the name: AutoCAD 2D Workalong 02-3. (Figure Step 16)

Figure Step 16

Step 17

Enter the CLOSE command to close the current drawing. If you are asked if you want to save the drawing, answer Yes.

Step 18

Minimize AutoCAD and open File Explorer. Find the folder:

C:\CAD Courses\AutoCAD 2D\Lab Exercises. You should see three drawing files either with or without the .dwg extension as shown in the figures. (Figure Step 18A and 18B)

Figure Step 18A
Figure Step 18B
AUTHOR’S COMMENTS: You may see some .bak files in your list with the same name as the drawing files. Note that drawing files have the AutoCAD icon preceding the drawing name. Figure Step 18A and 18B only shows the drawing files. If you see some .bak files, ignore them.

AutoCAD Commands

Most work in AutoCAD consists of you issuing instructions to AutoCAD. Those instructions are called commands. Commands are usually entered using the Command Line window, a Pull-down menu, a Toolbar menu, or a Ribbon menu. Figure 2-3 shows the LINE command being entered using all four methods.

Regardless of the way you enter a command, AutoCAD does not know or care where the command was initiated. To AutoCAD, all commands look alike, therefore you can choose which method you want to use. There is no right or wrong method to enter a command. Throughout the AutoCAD 2D book, the different methods of entering commands is shown and the you can decided which method to use.

Figure 2-3 Different Methods of Executing the LINE Command

Executing Commands

Some menu items execute commands automatically but most of the time it is up to you to execute the command. Executing a command is your way of telling AutoCAD that you are finished and AutoCAD should do what was commanded. A command can be executed by either pressing the Enter key or the Space Bar.

Repeating the Last Command

AutoCAD can be very repetitive. To work faster, the last command that was executed can be repeated by pressing the Enter key, the Space bar, or by right clicking the mouse.

Option Prompts

After most commands are executed, AutoCAD will respond with an option prompt. An option prompt is AutoCAD asking you a question in response to a command or requesting some user input. Figure 2-4 shows three commands and the option prompts returned by each one. Your input is shown in bold. In the LINE command, AutoCAD’s option prompt is

‘ Specify first point ‘ and you respond 2,2. AutoCAD then prompts ‘ Specify next point or [Undo]: ‘. It is important for you to watch the Command Line window to see what AutoCAD is asking from you next.

Figure 2-4 Option Prompts

Defaults

AutoCAD sets defaults for almost everything. A default is the value AutoCAD uses, if you do not supply one. Defaults are enclosed inside angle brackets ‘ < > ‘. If you want to use the default value, simply respond by pressing the Enter key or the Space bar. See Figure 2-5.

Figure 2-5 AutoCAD Defaults

Command Options

Command options are selections that you can choose from to change the default. Command options are enclosed inside ‘ [ ] ‘ as shown in Figure 2-5. An example of the defaults and options for the CIRCLE command are as follows:

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:

Specify center point for circle – is the default.

[3P/2P/Ttr (tan tan radius)] – are the options.

Cancelling or Aborting a Command

Commands can be cancelled or aborted by pressing the Esc key on the keyboard. Sometimes it must be pressed twice to completely abort the command and return to the Command: prompt.

MUST KNOW: The Enter key or the Space bar are used to execute commands. If either one is pressed when there is no active command, AutoCAD will repeat the last command. Right clicking the mouse will produce the same results.

USER TIP: AutoCAD’s option prompts are a combination of upper and lower case letters. To help you work faster, only enter the uppercase character(s) when entering an option. For example:

Command: LENGTHEN
Select an object or [Delta/Percent/Total/DYnamic]:
(For Delta, enter D, for Percent enter P, for Total enter T, and for DYnamic enter DY.)

WORKALONG: Entering, Executing, and Aborting Commands

Step 1

Using what you learned earlier in this module, start a new drawing using template: 2D English.

Step 2

Save the drawing with the name: AutoCAD 2D Workalong 02-4 in the Lab Exercises folder.

Step 3

Check to ensure that the Model tab is enabled. If it is not, enable it by clicking it with the left mouse button. (Figure Step 3)

Figure Step 3

Step 4

Disable all features on the Status bar by clicking any that are enabled. Your Status bar should match the figure. (Figure Step 4)

Figure Step 4

Step 5

Ensure that ByLayer is enabled in the first 3 boxes on the Properties toolbar or the Properties tab in the Ribbon menu. (Figure Step 5)

Ribbon Menu
Figure Step 5
AUTHOR’S COMMENTS: You will not be drawing anything in this module. You are learning how to enter commands and understand AutoCAD’s prompts and defaults. You will be aborting all commands after you enter them. Be patient, you will start drawing in Module 4.

Step 6

Look in the Command Line window. Note that when there is no active command, AutoCAD displays ‘ Type a command ‘ prompt. The prompt is AutoCAD asking you to enter a command. (Figure Step 6)

Figure Step 6

AUTHOR’S COMMENTS: If the prompt does not display as shown in Figure Step 6, press the Esc key until it does.

Step 7

Enter the LINE command by selecting Draw on the Pull-down menu. In the Draw Pull- down, select Line. (Figure Step 7)

Figure Step 7

Step 8

Note in the Command Line window AutoCAD is now prompting ‘ Specify first point: ‘. (Figure Step 8)

Figure Step 8

Step 9

Press Esc to abort (cancel) the command. (Figure Step 9)

Figure Step 9

Step 10

At the Command: prompt, enter the CIRCLE command by typing it on the keyboard. (Figure Step 10)

Figure Step 10

AUTHOR’S COMMENTS: Note that as you type the command, AutoCAD will suggest possible commands. If you see the command you want and it is blue, press the Enter key. If is grey, click it with the Graphic cursor to complete the full command.

Step 11

Press Enter to execute the command. Note how AutoCAD prompts ‘ Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: ‘ (Figure Step 11)

Figure Step 11

AUTHOR’S COMMENTS: The AutoCAD prompt means the following:

Specify center point for circle – The default.

[3P/2P/Ttr (tan tan radius)] – This is the option prompt. If you do not want to use the default, you can enter 3P, 2P or T to select one of the options.

Step 12

Enter a T and press Enter. Take note of the new prompt ‘ Specify point on object for first tangent of circle: ‘. (Figure Step 12)

Figure Step 12

Step 13

Press Esc to abort the command. (Figure Step 13)

Figure Step 13

Step 14

Enter the ARC command by typing it in on the keyboard. Press the Space bar to execute command. Press Esc to abort the command. (Figure Step 14)

Figure Step 14
AUTHOR’S COMMENTS: Note that a command can be executed by either pressing the Enter key or the Space bar.

Step 15

Press Enter without entering a command. Note how AutoCAD will repeat the last command. (Figure Step 15)

Figure Step 15

Step 16

Press Esc to abort the command to return to the Command prompt. (Figure Step 16)

Figure Step 16

Step 17

Enter the QSAVE command by either typing it on the keyboard. (Figure Step 17)

Figure Step 17
AUTHOR’S COMMENTS: Note how some commands do not prompt you for anything.

Step 18

Enter the CLOSE command to close the drawing. (Figure Step 18)

Figure Step 18

MUST KNOW: Command options are selections that you can choose from to change the command default. Command options are enclosed inside square brackets ‘ [ ] ‘.Select first object [Polyline/Radius/Trim] – Enter either a P, R or T to change the default.

AUTHOR’S COMMENTS: To sum up:

1. Either the Enter key or the Space bar can be used to execute a

2. If there is no active command, AutoCAD will repeat the last command if you press the Enter key, the Space bar, or right clicks the

3. The Esc key will abort (cancel) any command or process and return you to the Command: prompt.

4. Most AutoCAD command prompts contain a default and an option

5. A default is the value AutoCAD uses, if you do not supply one. Defaults are enclosed inside angle brackets ‘ < > ‘. If you want to use the default value, simply respond by pressing the Enter key or the Space

6. Option prompts are enclosed inside square brackets ‘ [ ] ‘.

MUST KNOW: The Esc key is a very important when drawing in AutoCAD. When pressed, it will abort or cancel any command or process and return you to the command prompt. You will be using this key frequently while working in AutoCAD.

Key Principles

Key Principles in Module 2

1. An AutoCAD drawing is a database file containing graphical and non-graphical data and must have the extension .dwg.

2. A drawing template is a drawing file that may contain layouts, defaults, blocks, and standards set by the creator of the template and must be used to start a new drawing.

3. The AutoCAD file extensions taught in the AutoCAD 2D book are .dwg, .dwt, and .bak. .dwg is a drawing file. .dwt is a template file. .bak is a backup file.

4. Regardless of the way commands are entered, AutoCAD doesn’t really know or care where the command was initiated.

5. A default is the value AutoCAD uses, if you do not supply one. Defaults are enclosed inside angle brackets ‘ < > ‘. If you want to use the default value, simply respond by pressing the Enter key or the Space bar.

6. In an AutoCAD command prompt, the options are enclosed inside square brackets ‘ [ ] ‘.

7. The Enter key or the Space bar are used to execute a command. If there is no active command and either the Enter key or Space bar are pressed, the last command will repeat. The same thing can be achieved by right clicking the mouse.

8. The Esc key will cancel or abort any AutoCAD command or process.

Lab Exercise 2-1

Time allowed: 30 minutes.

Step 1

Start a new drawing using the template: 2D English.

Step 2 IMPORTANT STEP

Unless otherwise instructed, each time you start a workalong or a lab exercise in the AutoCAD 2D book, the Model tab should be enabled. (Figure Step 2)

Figure Step 2

Step 3 IMPORTANT STEP

Unless otherwise instructed, each time you start a workalong or a lab exercise in the AutoCAD 2D book, all features on the Status bar should be disabled as shown in the figure. (Figure Step 3)

Figure Step 3

Step 4

If any icons in the Status bar are enabled as shown in Figure Step 4, click them until they are disabled as shown in Figure Step 3. (Figure Step 4)

Figure Step 4

Step 5 IMPORTANT STEP

Unless otherwise instructed, each time you start a workalong or a lab exercise in the AutoCAD 2D book, the first three box of the Properties toolbar or the Properties tab in Ribbon menu should be set ByLayer . (Figure Step 5)

Ribbon Menu
Figure Step 5 Toolbar Menu

Step 6

Save and name the drawing with the name: AutoCAD 2D Lab 02-1. Save the drawing in the folder: C:\CAD Courses/AutoCAD 2D/Lab Exercises. Using the CLOSE command, close the drawing.

Step 7

Complete the following:

C:\CAD Courses/AutoCAD 2D/Lab Exercises

Step 8

Complete the following:

Step 9

Minimize AutoCAD and open File Explorer. Locate the folder:

C:\CAD Courses/AutoCAD 2D/Lab Exercises. It should contain 7 drawing files, with or without the extension .dwg, as shown in the figure. (Figure Step 9A and 9B)

Figure Step 9A
Figure Step 9B
AUTHOR’S COMMENTS: You may see some .bak files in your list with the same name as the drawing files. Note that drawing files have the AutoCAD icon preceding the drawing name. Figure Step 9 only shows the drawing files. Your list may show some .bak files, ignore them.

3

Module 3: Checking the Accuracy of Your Drawings

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe how you can check the lab exercise drawings you complete in the AutoCAD 2D book for accuracy.
AUTHOR’S COMMENTS: It is extremely important to create all drawings with 100% accuracy. This cannot be stressed strongly enough as it is essential that each object in the drawing is positioned and sized perfectly. Most lab exercises in the AutoCAD 2D book can be checked for accuracy by overlaying the drawing with a key. This helps you to know when your drawing is accurate and will display any objects that are drawn incorrectly. As you become more experienced drawing in AutoCAD 2021, you will not require the use of keys. Interface varies slightly for each release.

WORKALONG: Checking the Accuracy of Your Drawings

Step 1

Using the NEW command, start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Lab 03-1. Save it in the folder: CAD Courses/AutoCAD 2D/Lab Exercises.

Step 3

Check to ensure that the Model tab is enabled. If it is not, enable it by clicking it with the left mouse button. (Figure Step 3)

Figure Step 3
AUTHOR’S COMMENTS: The Model tab should be enabled at all times, while working on workalongs and lab exercises in the AutoCAD 2D book, unless you are instructed otherwise. Module 18 will teach you how work in the Layout tabs.

Step 4

Ensure that all features on the Status bar are disabled by clicking any that are enabled. Your Status bar should match the figure. (Figure Step 4)

Figure Step 4
AUTHOR’S COMMENTS: Unless otherwise instructed, each time you start a workalong or lab exercise while working on the AutoCAD 2D book, all features on the Status bar should be disabled.

Step 5

Ensure that ByLayer is enabled in the first 3 boxes on the Properties menu. (Figure Step 5)

Properties Toolbar
Home Ribbon
Figure Step 5
AUTHOR’S COMMENTS: Unless otherwise instructed, each time you work on a workalong or a lab exercise while working on the AutoCAD 2D book, ByLayer should be enabled in the first three boxes on the Properties toolbar or Ribbon menu.

Step 6

Click Format on the Pull-down menu and click Units to open the Drawing Units dialogue box. (Figure Step 6A and 6B)

Figure Step 6A
Figure Step 6B

Step 7

Pull down the Insertion scale list and select Inches. Click OK to close the Drawing Units dialogue box. (Figure Step 7)

Figure Step 7

Step 8

Click Insert on the Pull-down menu and select Block. This will open the Insert dialogue box. (Figure Step 8A and 8B)

Figure Step 8A
Figure Step 8B
AUTHOR’S COMMENTS: The dialogue box in your AutoCAD may not match the figure exactly.

Step 9

Click the small triangle at the end of the Name: pull-down list to pull down the list of block names. (Figure Step 9)

Figure Step 9

Step 10

Select the name: AutoCAD 2D Lab 03-1. (Figure Step 10)

Figure Step 10
AUTHOR’S COMMENTS: Always select the name of the current drawing.

Step 11

Ensure that the three Specify On-screen boxes are disabled as shown in the figure. (Figure Step 11)

Figure Step 11
AUTHOR’S COMMENTS: After you do this step once, it will keep the same settings unless you intentionally change it.

Step 12

Ensure that the Insert dialogue box matches the figure and click the OK button. (Figure Step 12)

Figure Step 12
AUTHOR’S COMMENTS: This is just a demo, therefore there is nothing for you to do but learn the process of checking your drawing for accuracy with a key. You will be checking your first drawing for accuracy in Module 4.

Step 13

This will insert a magenta colored key on your drawing. (Figure Step 13)

AUTHOR’S COMMENTS: If you see double objects or places where the red objects and the key’s magenta objects do not match, your drawing is inaccurate. If there is only one object, even though it may share the colors magenta and red, your drawing is accurate. If the drawing is inaccurate, disable the key’s display and correct the drawing. Enable the key’s display and recheck it for accuracy. When your drawing matches the key, save and close the drawing and go on to the next lab exercise or module. Module 5 will teach you how to disable and enable the key’s display.
Figure Step 13

Step 14

Save and close the drawing.

Key Principles

Key Principles in Module 3

  1. AutoCAD drawings must be drawn 100% accurate.
  2. You can check the accuracy of most lab exercise drawings in the AutoCAD 2D book using a key.
  3. The name of the key that you select to check your drawing for accuracy is always the same as the name of the current drawing.
  4. Your drawing is not accurate if the magenta objects in the key do not match your drawing objects. If you only see one object, either magenta or red, your drawing is 100% accurate.

4

Module 4: Drawing Lines Using Cartesian Coordinates

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe the geometry of points and lines.
  2. Describe the Cartesian Coordinate System.
  3. Define and explain the terms lastpoint, absolute coordinates, and relative coordinates.
  4. Apply the LINE command to draw lines using the XY Cartesian Coordinate System using both absolute and relative coordinates.

Geometry Lesson: Points and Lines

A point is defined as a single XY coordinate. It does not have a width, height, or depth. A line is the shortest distance between two XY coordinates. Lines can be horizontal, vertical, or inclined. Lines that are the same distance apart are called parallel lines. Perpendicular lines are at right angles to each other or 90 degrees apart. See Figure 4-1 and 4-2.

Figure 4-1 Points and Lines
Figure 4-2 Parallel and Perpendicular Lines

The Cartesian Coordinate System

To accurately draw an AutoCAD two dimensional (2D) drawing, you must enter XY coordinate locations. These XY coordinates are based on the Cartesian Coordinate System.

Figure 4-3 The Cartesian Coordinate System

The Cartesian Coordinate System consists of two numbered lines crossing perpendicular to one another at their zero values. The horizontal axis is the X axis and the vertical axis is the Y axis. See Figure 4-3. A coordinate value is assigned to each location on the current construction plane. Throughout the AutoCAD 2D book you will be working on the same construction plane. Construction planes are fully explained in the AutoCAD 3D book.

When you are using a AutoCAD 2D command, each coordinate value consists of a pair of numbers, the first is the X coordinate and the second is the Y coordinate, written X,Y. The X and Y values must be separated by a comma. For example, X2,Y4 (entered in AutoCAD as 2,4) is the location 2 units to the right (positive) and 4 units up (positive) from X0,Y0 or 0,0.

The values can be either positive or negative. Positive numbers are default so the plus sign is not required. If the value is negative, the minus sign must precede the number. For example if entered in a an AutoCAD command, -3,5 is X minus 3 and Y positive 5.

Cartesian coordinates can be entered in a AutoCAD command as either absolute coordinates or relative coordinates.

Absolute Cartesian Coordinates

Absolute Cartesian Coordinates are always referenced to the absolute origin 0,0. The Absolute Cartesian Coordinate 3,4 (X3Y4) is 3 units to the right and 4 units upwards from 0,0 (X0Y0).

Negative values can also be used. The Absolute Cartesian Coordinate -4,2 (X-4,Y2) is 4 units to the left and 2 units upwards from 0,0 (X0Y0).

Relative Cartesian Coordinates

Relative Cartesian Coordinates are incremental to the lastpoint. To indicate to AutoCAD that the coordinate being entered is relative, the @ symbol must precede the coordinate value. For example, @2,6, which means ‘ from the lastpoint go 2 units in the positive X and 6 units in the positive Y ‘. Another example using negative values @4,-2 which means ‘ from the lastpoint go 4 units in the positive X and 2 units in the negative Y.

Lastpoint

The lastpoint is the last XY location that was used in an AutoCAD command. The lastpoint is very important to you when drawing in AutoCAD. AutoCAD remembers the lastpoint entered and saves it in the @ symbol. The @ symbol means ‘ The last absolute coordinate location ‘.

USER TIP: When you start a drawing, the first XY location is always specified using an absolute coordinate. After that, relative coordinates are used. It would be too difficult to draw using all absolute coordinates.

AutoCAD Command: LINE

The LINE command is used to draw lines.

Shortcut: L

WORKALONG: Drawing Lines Using Cartesian Coordinates – Part 1

Step 1

Using the NEW command, start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 04-1. Save it in the folder: CAD Courses/AutoCAD 2D/Lab Exercises

Step 3

Enter the LINE command, as shown below, to draw the object shown in the figure. Keep in mind that you enter what is in bold font, the author’s comments are in italics, and everything else are AutoCAD responses or prompts. (Figure Step 3)

Figure Step 3

Command: LINE

Specify first point: 1.75,4

(Always start with an absolute coordinate. It must be a X then a Y separated with a comma.)

Specify next point or [Undo]: @5,0

(Then change to relative coordinates. Note the @ first, then X and Y.)

Specify next point or [Undo]: @0,2

Specify next point or [Close/Undo]: @-2.5,0

(A negative coordinate is used since the line is going in the negative X direction.)

Specify next point or [Close/Undo]: @0,1.5

Specify next point or [Close/Undo]: @-1,1

(When both the X and Y coordinates have a value other then zero, the line will be inclined.)

Specify next point or [Close/Undo]: @-1.5,0

Specify next point or [Close/Undo]: C

(You can use a C or 1.75,4 to close the last line and return to the first point.)

Command:

AUTHOR’S COMMENTS: Rather then just entering the coordinate values, try to understand the values you are entering by studying the Figure Step 3.

Step 4

Your completed drawing should match the figure. (Figure Step 4)

Figure Step 4
AUTHOR’S COMMENTS: If you have trouble drawing this object the first try, do not be concerned. Start it over again, from scratch, until you can complete it. The more practice you get drawing, the easier it will get.

Step 5

Save and close the drawing.

MUST KNOW: When drawing inclined lines using Cartesian Coordinates, the value of both the X and the Y coordinates cannot be zero. See example below.

Figure 4-4 Drawing Inclined Lines Using Cartesian Coordinates

Command: LINE

Specify first point: 4,3

Specify next point or [Undo]: @0,2

Specify next point or [Undo]: @-1.5,1

Specify next point or [Close/Undo]: @-1,0

Specify next point or [Close/Undo]:

Command:

Note to draw the inclined line, you have to enter a X value and a Y value that is not zero. In this example, @-1.5,1 If either X or the Y is zero, then the line would be either horizontal or vertical. See Figure 4-4.

In Module 10, you will be taught how to draw incline lines using Polar Coordinates.

WORKALONG: Drawing Lines Using Cartesian Coordinates – Part 2

Step 1

Using the NEW command, start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 04-2. Save it in the folder: CAD Courses/AutoCAD 2D/Lab Exercises

Figure Step 3

Step 3

Enter the LINE command, as shown below, to draw the object shown in the figure. (Figure Step 3)

Command: L

(L is the shortcut for the LINE command)

Specify first point: 7,5

Specify next point or [Undo]: @0,2

Specify next point or [Undo]: @-2,0

Specify next point or [Close/Undo]: @.75,1

(You can draw an inclined line by entering a number other then zero for both the X and Y.)

Specify next point or [Close/Undo]: @-3.5,0

Specify next point or [Close/Undo]: @-.75,-1

Specify next point or [Close/Undo]: U

(When you make an input error, enter a U to go back one step. More than one U can be entered to step back further. Ensure that you press the ENTER or SPACE after each one.)

Specify next point or [Close/Undo]: @.75,-1

Specify next point or [Close/Undo]: @-2,0

Specify next point or [Close/Undo]: @0,-2

Specify next point or [Close/Undo]: @1,0

Specify next point or [Close/Undo]: @0,.5

Specify next point or [Close/Undo]: @4,0

Specify next point or [Close/Undo]: @0,-.5

Specify next point or [Close/Undo]: 7,5

(The object was closed by entering the absolute coordinate of the first point.)

Specify next point or [Close/Undo]: Command:

Step 4

Your completed object should match the figure. (Figure Step 4)

Figure Step 4
AUTHOR’S COMMENTS: If you have trouble drawing this object the first try, do not be concerned. Start it over again, from scratch, until you can complete it. The more practice you get drawing, the easier it will get.

Step 5

Save and close the drawing.

USER TIP: When entering a decimal number the ends in a zero, for example 4.0, enter the number up to the zero only. In this case, 4. If the number is 3.6700, all you have enter is 3.67. AutoCAD will automatically adds the zeros.

Deleting Objects

To delete existing drawing objects, you can either use the ERASE command or the Delete key.

Using the ERASE Command

When deleting drawing objects using the ERASE command, the drawing objects can either be selected before or after the command is entered. If the command is entered before selecting the objects, select the objects when prompted by the ‘ Select Object ‘ prompt, as shown below. If the objects are selected before entering the ERASE command, there is no prompt.

Command: ERASE

Select Object:

Command:

Using the Delete Key

When deleting objects using the Delete key, select the object or objects before pressing the key.

AutoCAD Command: ERASE

The ERASE command is used to permanently remove drawing objects from the drawing.

Shortcut: E

WORKALONG: Deleting Drawing Objects

Step 1

Open the drawing: AutoCAD 2D Workalong 04-1.

Step 2

Using the SAVEAS command, save the drawing with the name: AutoCAD 2D Workalong 04-3. (Figure Step 2)

Figure Step 2

Step 3

Enter the ERASE command as shown below. Move the pickbox onto the horizontal line and select it by pressing the left mouse button. Move the cursor onto the vertical line and select it. Press the Enter key to execute the command. (Figure Step 3A, 3B, and 3C)

Command: ERASE

Select objects: 1 found

Select objects: 1 found, 2 total Select objects:

Command:

Figure Step 3A
Figure Step 3B
Figure Step 3C
AUTHOR’S COMMENTS: When you select a drawing object inside a command they will highlight and appear dashed.
MUST KNOW: The lastpoint is the last XY location that was used in an AutoCAD command. The lastpoint is very important to you when drawing in AutoCAD. AutoCAD remembers the lastpoint entered and saves it in the @ symbol. The @ symbol means ‘ The last absolute coordinate location ‘.

Step 4

To delete drawing objects without entering a command, move the pickbox onto the lines,

as shown in the figure, and select them by clicking the left mouse button. They will highlight and appear dashed with small blue squares on them. When the lines display as shown in the figure, press the Delete key on the keyboard. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 3A
Completed Drawing
AUTHOR’S COMMENTS: The small blue squares that display on a selected object when selected are called grips. You will learn more about them later in the book and how to use them in the AutoCAD 2D Advanced book.
AUTHOR’S COMMENTS: If you want to unselect one or more drawing objects, press the Esc key. Sometime you have to press it twice to totally unselect the selected objects.

Step 5

Save and close the drawing.

MUST KNOW: To enter a positive number in AutoCAD, enter the number only. Positive is the AutoCAD default. If the number is negative, the ‘ – ‘ sign must precede the number. For example, if the number is 4.0, enter 4. If the number is -4.0, enter -4.

Key Principles

Key Principles in Module 4

  1. The Cartesian Coordinate System consists of two numbered lines crossing perpendicular to one another at their zero values. The horizontal axis is the X axis and the vertical axis is the Y axis.
  2. Absolute Cartesian Coordinates are always referenced to the absolute origin 0,0.
  3. The @ symbol means ‘ The last absolute coordinate location ‘ or sometimes called the lastpoint. Relative Cartesian Coordinates must be preceded with @ symbol.
  4. To close the last line of a series of lines, enter either ‘ C ‘ (Close) or the absolute coordinate of the first point.
  5. To delete existing drawing objects, you can either use the ERASE command or the Delete key.
  6. Objects can either be selected before or after a command is entered.
  7. To unselect a selected drawing object, press the Esc key. Sometimes it has to be pressed twice.

Lab Exercise 4-1

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 04-1 2D English Inches

Step 1

Start a new drawing using the template shown above.

Step 2

Save and name the drawing: AutoCAD 2D Lab 04-1 in the folder: CAD Courses/AutoCAD 2D/Lab Exercises.

Step 3

Using the LINE command, draw the object shown in the figure. (Figure Step 3A and 3B)

Figure Step 3A
Completed Drawing
Figure Step 3B

Step 4

Enter the UNITS command. In the Drawing Units dialogue box, set the Insertion Units to Inches. (Figure Step 4)

Figure Step 4
AUTHOR’S COMMENTS: You can find the Insertion scale in the Units column in the table under the lab exercise title.

Step 5

Check your drawing with the key. The key name is the same as the drawing name. (Figure Step 5)

Figure Step 5
AUTHOR’S COMMENTS: If you have trouble doing this, redo Module 3.

Step 6

Your drawing should match the figure. (Figure Step 6)

Figure Step 6
AUTHOR’S COMMENTS: Step 5 will insert a magenta colored overlay key on your drawing. If you see double objects or places where your objects and the magenta objects do not match, your drawing is inaccurate. If you only see one object, even though it may share the colors magenta and red, your drawing is accurate.
AUTHOR’S COMMENTS: If you have trouble completing this drawing the first try, do not be concerned. Start it over again, from scratch, until you can complete it. The more practice you get drawing, the easier it will get. When you get to Module 8, you will be taught how to fix a drawing so that you do not have to start over.

Step 7

Save and close the drawing.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hint. If you get stuck and can not complete it on your own, use the following hint to help you.

Hint 1

See Figure Hint 1.

Figure Hint 1

Lab Exercise 4-2

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 04-2 2D Metric Millimeters

Step 1

Start a new drawing using the template shown above.

Step 2

Save and name the drawing: AutoCAD 2D Lab 04-2 in the folder: CAD Courses/AutoCAD 2D/Lab Exercises.

Step 3

Using the LINE command, draw the object shown in the figure. (Figure Step 3A and 3B)

Figure Step 3A
Completed Drawing
Figure Step 3B

Step 4

Enter the UNITS command. In the Drawing Units dialogue box, set the Insertion Units to Millimeters. (Figure Step 4)

Figure Step 4

Step 5

Check your drawing with the key. The key name is the same as the drawing name. (Figure Step 5)

Figure Step 5

AUTHOR’S COMMENTS: If you have trouble doing this, redo Module 3.

Step 6

Your drawing should match the figure. (Figure Step 6)

Figure Step 6
AUTHOR’S COMMENTS: Step 5 will insert a magenta colored overlay key on your drawing. If you see double objects or places where your objects and the magenta objects do not match, your drawing is inaccurate. If you only see one object, even though it may share the colors magenta and red, your drawing is accurate.
AUTHOR’S COMMENTS: If you have trouble completing this drawing the first try, do not be concerned. Start it over again, from scratch, until you can complete it. The more practice you get drawing, the easier it will get. When you get to Module 8, you will be taught how to fix a drawing so you do not have to start over.

Step 7

Save and close the drawing.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hint. If you get stuck and can not complete it on your own, use the following hint to help you.

Hint 1

See Figure Hint 1.

Figure Hint 1

Lab Exercise 4-3

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 04-3 2D English Inches

Step 1

Start a new drawing using the template shown above.

Step 2

Save and name the drawing: AutoCAD 2D Lab 04-3 in the folder: CAD Courses/AutoCAD 2D/Lab Exercises.

Step 3

Using the LINE command, draw the object shown in the figure. (Figure Step 3A and 3B)

Figure Step 3A
Figure Step 3B
Completed Drawing

Step 4

Enter the UNITS command. In the Drawing Units dialogue box, set the Insertion Units to Inches.

Step 5

Check your drawing with the key.

Step 6

Save and close the drawing.

5

Module 5: Layers

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe AutoCAD’s layering system.
  2. Apply the LAYER command to create, toggle on/off, thaw/freeze, lock/unlock, select color, and set the current layer in the current drawing.

Layers

AutoCAD’s layering system is one of its most important features. Layers allow you to organize, segregate, set the drawing object’s color and linetype, control the visibility, and manage plotting of the drawing.

Think of layering as being able to draw on transparent overlays with each overlay containing relevant or grouped objects as shown in Figure 5-1. When all of the overlays are stacked together as shown in Figure 5-2, you can see and work on all of them. At any time, while you are working on drawing or printing it, you can control the layer’s visibly.

Figure 5-1 Layers Seen as Overlays

There is no limit to the number of layers that can be created in an AutoCAD drawing. Layers can be named by you or you can allow AutoCAD to automatically name them. A color, linetype, lineweight, and plot style can also be assigned. In this module, only naming and assigning a color to layers will be taught.

In addition to what was just discussed, the visibility of each layer can be controlled by toggling layers off or on and freezing or thawing them. A layer can also be locked to prevent objects on them from being modified.

Figure 5-2 Stacked Layers

AutoCAD’s Special Layer

AutoCAD has a special layer, named 0 (the number zero). Each new drawing created in AutoCAD will automatically contain this layer. It cannot be deleted or renamed. The importance of layer 0 will be discussed further in future modules.

The Current Layer

The current layer is the layer that AutoCAD will place all newly created drawing objects on. One layer is current at all times. The current layer can be turned off but never frozen. You can change which layer is the current layer at any time.

ByLayer vs ByObject

AutoCAD assigns the color, linetype, and lineweight properties to drawing objects either ByLayer or ByObject. In the AutoCAD 2D book, all work is done ByLayer. An easy way for you to check if you are working ByLayer is to look at the first three boxes in Properties menu as shown in Figures 5-3 and 5-4.

Figure Step 5-3 Home Ribbon
Figure 5-4 Properties Toolbar

The three properties boxes should always display the words ByLayer as shown in the figure.

Simply, ByLayer means that when a drawing object is inserted into the drawing or an existing drawing object is regenerated, it looks in the drawing’s database to see what color, linetype, and lineweight it should display. If it is set ByLayer, it checks what layer the drawing object resides on and displays the color, linetype, and lineweight assigned to that layer. Most company standards require the color, linetype, and lineweight properties of their drawings to be drawn Bylayer.

It is important to know the different between a layer that is Off and a layer that is Frozen. A layer that is Off does NOT display but WILL regenerate. A layer that is Frozen does NOT display and will NOT regenerate. The importance of this will become apparent in future AutoCAD 2D modules.

Study the following four properties and their symbols:

On/Off:

Toggles the drawing object’s display on that layer on or off. In other words, visible or not visible.

Freeze/Thaw:

Toggles the layer to be frozen or thawed. The drawing objects on a frozen layer are not visible and do not regenerate. The objects on a thawed layer are visible and will regenerate.

Lock/Unlock:

Toggles the layer locked or unlocked. Drawing objects on a locked layer are visible but cannot be modified or deleted. Drawing objects on an unlocked layer are visible and can be modified or deleted.

Color:

Sets the color for the layer. All drawing objects on that layer, with the property ByLayer, will display the color assigned to the layer.

AutoCAD Command: LAYER

The LAYER command is used to open the Layer Property Manager window.

Shortcut: LA

Layer Toolbar
Format Pull-down
Home Ribbon
MUST KNOW: The current layer can be turned off but CANNOT be frozen. To freeze it, set one of the other layers as the current layer.

WORKALONG: Working with Layers

Step 1

Using the NEW command, start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 05-1. Save it in the folder: CAD Courses/AutoCAD 2D/Lab Exercises

Step 3

Enter the LAYER command to open the Layer Properties Manager window. (Figure Step 3)

Figure Step 3
AUTHOR’S COMMENTS: Take note of layer 0 (zero). It exists in all AutoCAD drawings and cannot be deleted or renamed. The other two layers are part of the template drawings, ignore them for now. Note the Check Mark icon beside layer 0. This indicates it is the current layer.

Step 4

Click the small arrow in the upper right of the Filters area to close it. (Figure Step 4)

Figure Step 4
AUTHOR’S COMMENTS: You can leave the Filter Area closed for the duration of this book. Layer filters are taught in the AutoCAD 2D Advanced book.

Step 5

Click the New Layer icon. AutoCAD will create a new layer and automatically name it: Layer1. (Figure Step 5A and 5B)

Figure Step 5A
Figure Step 5B

Step 6

Rename the layer to: Object. (Figure Step 6.)

Figure Step 6

Step 7

Set the color of layer: Object by clicking the color name white. This will open the Select Color dialogue box. Enable the Index Color tab. Select the color red by clicking it or enter the name in the Color box. Click OK to close the dialogue box. (Figure Step 7A and 7B)

Figure Step 7A
Figure Step 7B
MUST KNOW: Unless otherwise instructed while working in the AutoCAD 2D book, select the colors from the Standard Color Palette in the Index Color tab as shown in the figure on the right. The colors included in this palette are the common colors and are named. White and black are the same color to AutoCAD. White will display black on a white background and black will display white on a black background.

Step 8

Click layer: Object to highlight it. Click the Set Current icon. (Figure Step 8A and 8B)

Figure Step 8A
Figure Step 8B

AUTHOR’S COMMENTS: The Green Check Mark icon in the Status column indicates that the current layer is Object as you can see in Figure Step 8B.

Step 9

Toggle the on/off, thaw/frozen, and lock/unlock properties of the layers by clicking the icons to match the figure. Close the window by clicking the X in the top left corner. (Figure Step 9A and 9B)

Figure Step 9A
Figure Step 9B
AUTHOR’S COMMENTS: Once you have created the layers in the drawing, you can use the Layer toolbar menu, to change the current layer or to toggle the layer properties. This is much faster than using the Layer Properties Manager window. The Layer toolbar’s display should always be enabled and located across the top left side of the Graphic window.

Step 10

Take note how the current layer will display in the Layer toolbar. In this case, it is Object. (Figure Step 10)

Figure Step 10

Step 11

Pull down the layer list by clicking the small triangle on the right side. Change the current layer to 0 by clicking the layer name. (Figure Step 11A and 11B)

Figure Step 11A
Figure Step 11B

Step 12

Pull down the layer list again and this time toggle the layer properties so that all four layer are on, thawed, and unlocked. (Figure Step 12)

Figure Step 12

Step 13

Change the current layer to: Object. (Figure Step 13A and 13B)

Figure Step 13A
Figure Step 13B

Step 14

Save and close the drawing.

MUST KNOW: It is important to know the difference between a layer that is Off and a layer that is Frozen. A layer that is Off does NOT display but WILL regenerate. A layer that is Frozen will NOT display and will NOT regenerate. This is important as you will learn as you work your way through the book.
USER TIP: To quickly set the current layer in the Layer Property Managers window, double click the Status icon beside the layer name as shown in the figures below.
MUST KNOW: AutoCAD does not know the difference between the colors black and white. On a black background, the color black will display white and on a white background, the color white will display black.

MUST KNOW: AutoCAD has a special layer named 0 (the number zero). Each new AutoCAD drawing will contain layer 0 . It cannot be deleted or renamed. It has other special attributes as you will see in future modules.

USER TIP: In Module 3, you were shown how to insert a key onto your drawing to check it’s accuracy. The key resides on the layer Key. If you are required to work on your drawing after you inserted the key, toggle layer Key off. To re-check your drawing after you finish the editing, toggle layer Key on as shown in the figures below.

Key Off
Key On

MUST KNOW: The current layer is the layer that any newly created drawing object will reside on. It is important to always be aware of what the current layer is before creating drawing objects. The current layer cannot be frozen.

Key Principles

Key Principles in Module 5

  1. AutoCAD’s layering system is one of the most important AutoCAD features. Layers allow you to organize, segregate, set the drawing object’s color, control the visibility, and manage plotting of the drawing.
  2. The current layer is the layer that any newly created drawing object will reside on.
  3. AutoCAD has a special layer named 0 (the number zero). Each new drawing created in AutoCAD will automatically contain layer 0. It cannot be renamed or deleted.
  4. A layer that is Off, does NOT display but WILL A layer that is frozen does NOT display and will NOT regenerate.
  5. The current layer can be turned off but not frozen.

Lab Exercise 5-1

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 05-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Object All lines Red

Step 1

Start a new drawing using the template shown above.

Step 2

Save and name the drawing: AutoCAD 2D Lab 05-1. Save it in the folder: CAD Courses/AutoCAD 2D/Lab Exercises.

Step 3

Create a new layer and name it: Object. Set its color red, as shown in the Layering Scheme above.

Step 4

Draw the object shown in the figure. All lines should be on layer: Object and display red. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 4B

Step 5

Enter the UNITS command. In the Drawing Units dialogue box, set the Insertion Units to Inches. (Figure Step 5)

Figure Step 5

AUTHOR’S COMMENTS: You can find the Insertion scale in the Units column in the lab exercise title.

Step 6

Check your drawing with the key. The key name is the same as the drawing name. (Figure Step 6)

Figure Step 6

AUTHOR’S COMMENTS: If you have trouble doing this, redo Module 3.

Step 7

The drawing should match the figure. (Figure Step 7)

Figure Step 7

AUTHOR’S COMMENTS: Step 6 will insert a magenta colored overlay key on your drawing. If you see double objects or places where your objects and the magenta objects do not match, your drawing is inaccurate. If you only see one object, even though it may share the colors magenta and red, your drawing is accurate.

AUTHOR’S COMMENTS: If you have trouble completing this drawing the first try, do not be concerned. Start it over again, from scratch, until you can complete it. The more practice you get drawing, the easier it will get. When you get to Module 8, you will be taught how to fix a drawing so you do not have to start over.

Step 8

Pull down the layer list and turn layer: Key off. (Figure Step 8A and 8B)

Figure Step 8A
Figure Step 8B

AUTHOR’S COMMENTS: If you had made errors on the drawing you first have to turn layer Key off. Then you can make the changes to the drawing. After you make the changes, turn layer Key back on , as done in Step 9, to check the accuracy of your changes.

Step 9

Pull down the layer list and turn layer Key on. (Figure Step 9A and 9B)

Figure Step 9A
Figure Step 9B

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hint. If you get stuck and cannot complete it on your own, use the following hint to help you.

Hint 1

Figure Hint 2

Lab Exercise 5-2

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 05-2 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Object All lines Red

Step 1

Start a new drawing using the template shown above.

Step 2

Save and name the drawing: AutoCAD 2D Lab 05-2. Save it in the folder: CAD Courses/AutoCAD 2D/Lab Exercises.

Step 3

Create the layer: Object, color red, as shown in the Layering Scheme above.

Step 4

Draw the object shown in the figure. All lines should be on layer: Object and display red. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 4B
Completed Drawing

Step 5

Enter the UNITS command. In the Drawing Units dialogue box, set the Insertion Units to Millimeters. (Figure Step 5)

Figure Step 5
AUTHOR’S COMMENTS: You can find the Insertion scale in the Units column in the lab exercise title.

Step 6

Check your drawing with the key. The key name is the same as the drawing name. (Figure Step 6)

Figure Step 6

Step 7

Your drawing should match the figure. (Figure Step 7)

Figure Step 7
AUTHOR’S COMMENTS: Step 6 will insert a magenta colored overlay key on your drawing. If you see double objects or places where your objects and the magenta objects do not match, your drawing is inaccurate. If you only see one object, even though it may share the colors magenta and red, your drawing is accurate.
AUTHOR’S COMMENTS: If you have trouble completing this drawing the first try, do not be concerned. Start it over again, from scratch, until you can complete it. The more practice you get drawing, the easier it will get. When you get to Module 8, you will be taught how to fix a drawing so you do not have to start over.

Step 8

Save and close the drawing.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hint. If you get stuck and cannot complete it on your own, use the following hint to help you.

Hint 1

Figure Step Hint 1

6

Module 6: Competency Test 1 Open Book

Learning Outcomes

When you have completed this module, you will be able to:

  1. Within a one-hour time limit, complete a written exam and a lab exercise without the aid of a key.

The AutoCAD 2D book was written with competency based modules. What that means is that you have not completed each module until you have mastered it. The Competency Test module contains multiple choice questions and a comprehensive lab exercise to test your mastery of the set of modules that you completed. There are no answers or keys supplied in a Competency Test module since it is meant to be checked by your instructor. If there are any parts of this module that you have trouble completing, you should go back and reread the module or modules containing the information that you are having trouble with. If necessary, redo as many lab exercises required until you fully understand the material.

If you are completing this book:

Multiple Choice Questions

Select the BEST answer.

  1. What two keyboard keys, when pressed, execute a command or accept an AutoCAD default?
    1. Esc and Space Bar
    2. Enter and Esc
    3. Enter and Space Bar
    4. F2 and Enter
    5. Space Bar and F6
  2. To AutoCAD, what does the @ symbol mean?
    1. A default
    2. An option
    3. Abort
    4. Execute
    5. The last absolute coordinate
  3. What keyboard key opens and closes the Text window?
    1. F1
    2. F2
    3. F3
    4. F4
    5. F6
  4. What is the main purpose of the left mouse button?
    1. To execute a command
    2. The pick button
    3. The abort button
    4. Repeats the last command
    5. The menu button
  5. What is the name of AutoCAD’s special layer that exists in all new drawings and cannot be
    deleted?
    1. 0 (zero)
    2. Object
    3. 2
    4. Special
    5. Layer 1
  6. What keyboard key aborts an AutoCAD command?
    1. F2
    2. Ctrl
    3. Esc
    4. F6
    5. Shift
  7. When a drawing object is inserted in a drawing, what layer will AutoCAD place it on?
    1. Layer 0 (zero)
    2. The last layer used
    3. The current layer
    4. The object layer
    5. The displayed layer
  8. Which layer cannot be frozen?
    1. Layer 0 (zero)
    2. The last layer used
    3. Any layer that is currently displayed
    4. The object layer
    5. The current layer
  9. Which one of the following inputs the relative coordinate location X2Y4?
    1. 2,4
    2. 4,2
    3. <2,4>
    4. @2,4
    5. #2,4
  10. What is the name of the file that contains the AutoCAD defaults and standards set by the creator?
    1. The template file
    2. The object file
    3. The backup file
    4. The text file
    5. The readme file

Lab Exercise 6-1 OPEN BOOK

Drawing Name Template Units
AutoCAD 2D Lab 06-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Object All lines Red

Step 1

Start a new drawing using the template shown above.

Step 2

Save and name the drawing: AutoCAD 2D Lab 06-1.

Step 3

Create layer: Object, color red, as shown in the Layering Scheme above.

Step 4

Draw the object shown in the figure. All lines should be on layer: Object and display red. (Figure Step 4A and 4B)

Figure Step 4A
Completed Drawing
Figure Step 4B
AUTHOR’S COMMENTS: TYP means typical. This simply means that there is at least one other dimension that is the same. In this drawing, the opposite side of the slot on the bottom of the object is the same size as the dimensioned one.

Step 5

Save and close the drawing.

AUTHOR’S COMMENTS: There is no key for this lab.

II

Part 2

7

Module 7: Circles and Arcs

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe the geometry of circles and arcs.
  2. Apply the CIRCLE and ARC commands to draw circles and arcs.
  3. Describe how to undo a command or redo an undo.

Geometry Lesson: Circles

A circle is defined as a closed curve in which all points are the same distance from its center point. The center point is a single XY coordinate.

A circle is 360 degrees and can be divided into four quadrants. All points on a circle are at a given distance from is center point. The distance between any of the points and the center is called the radius.

Study the drawings in Figure 7-1, 7-2, 7-3, and 7-4 for a description of the geometry of a circle.

Figure 7-1 Geometry of a Circle – Part 1
Figure 7-2 Geometry of a Circle – Part 2
Figure 7-3 Geometry of a Circle – Part 3
Figure 7-4 Geometry of a Circle – Part 4

Geometry Lesson: Arcs

An arc is defined as an open curve in which all points are the same distance from its center point. Study the drawings in Figure 7-5 and 7-6.for a description of the geometry of an arc.

Figure 7-5 Geometry of an Arc – Part 1
Figure 7-6 Geometry of an Arc – Part 2

AutoCAD Command: CIRCLE

The CIRCLE command is used to draw circles.

Shortcut: C

Draw Toolbar
Draw Pull-down
Home Ribbon

AutoCAD Command: ARC

The ARC command is used to draw arcs.

Shortcut: A

Draw Toolbar
Draw Pull-down
Home Ribbon
MUST KNOW: When you are drawing arcs, it is best to specify the center point first and the start point second. The radius and the direction of the arc can be entered at the same time. Enter the angle or the end point to complete the arc.
Figure 7-7 Constructing an Arc

Command: ARC

Specify start point of arc or [Center]: C

Specify center point of arc: 3,4

Specify start point of arc: @0,-2

(Specifying the radius and the direction for the start point.)

Specify end point of arc or [Angle/chord Length]: A

Specify included angle: 180

Command:

WORKALONG: Drawing Circles and Arcs

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 07-1.

Step 3

Create layer: Object, color red. Set it as the current layer. (Figure Step 3)

Figure Step 3

Step 4

Using the figures and what you already leaned, draw the two lines shown in Figure Step 4B. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 4B
AUTHOR’S COMMENTS: Draw the two lines using the LINE command twice.
USER TIP: By default, AutoCAD draw arcs counterclockwise which is the positive arc angle. If you use the Angle option, AutoCAD allows you to draw an arc by entering a negative angle.

Step 5

Enter the ARC command, as shown below, to draw the arc. (Figure Step 5)

Command: ARC

Specify start point of arc or [Center]: C

(If possible, always draw arcs starting with the center point first.)

Specify center point of arc: 2.5, 5

(Enter the center point.)

Specify start point of arc: @4,0

(Enter the start point. Here the trick is to give AutoCad the start point and the radius of the arc at the same time)

Specify end point of arc or [Angle/chord Length]: A

Specify included angle: 90

(Enter the angle of the arc. In this case, it is 90 degrees.)

Command:

Figure Step 5
USER TIP: Arcs can be drawn in either counterclockwise or clockwise direction by holding down the CTRL key, while in the ARC command, to reverse the direction.

Step 6

Enter the CIRCLE command, as shown below, to draw the four circles to complete the drawing. (Figure Step 6A and 6B)

Command: CIRCLE

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 3.5,6

(Since this is the first circle, enter an absolute coordinate for the center point.)

Specify radius of circle or [Diameter]: D

(Circles are usually dimensioned with diameters rather then a radius, enter D)

Specify diameter of circle: 0.65

Command: CIRCLE

(Press Enter or Space bar as that will repeat the last command.)

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @1,0

(Notice here, since AutoCAD always remembers the lastpoint, use an @. The lastpoint was the center of the first circle placed.)

Specify radius of circle or [Diameter] <0.3250>: D

Specify diameter of circle <0.6500>: 0.75

Command: CIRCLE (Press Enter or Space bar as that will repeat the last command.

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @0,1.5

(Use an @ from the center of the last circle drawn.)

Specify radius of circle or [Diameter] <0.3750>: D

Specify diameter of circle <0.7500>: 1

Command: CIRCLE

(Press Enter or Space bar. That will repeat the last command and save you entering it again.)

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @-1,0

Specify radius of circle or [Diameter] <0.5000>: D

Specify diameter of circle <1.0000>: 0.5

Command:

Figure Step 6A
Figure Step 6B

Step 7

Save and close the drawing.

WORKALONG: Drawing Circles Using the TTR Option

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 07-2.

Step 3

Create layer: Object, color red. Set it as the current layer. (Figure Step 3)

Figure Step 3

Step 4

Using the dimensioned drawing as a guide and what you already learned, use the LINE command to draw the four outside lines. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 4B

Step 5

Enter the CIRCLE command and the TTR option, as shown below, to insert the 2 inch diameter circle. (Figure Step 5A and 5B)

Command: CIRCLE

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: TTR

Specify point on object for first tangent of circle: P1

(Using the graphic cursor, move it on the top horizontal line. When the tangent snap icon appears, press the left mouse button.)

Specify point on object for second tangent of circle: P2

(Move the cursor on the vertical line. When the tangent icon appears, pick it.)

Specify radius of circle <0.7000>: 1

(Enter the radius of the circle. Be careful, since circles are usually dimensioned in diameters you will have to divide it in half.)

Command:

Figure Step 5A
Figure Step 5B

AUTHOR’S COMMENTS: TTR means ‘ Tangent Tangent Radius ‘. Do not enter the P1 or P2 on the keyboard. They simply mean Pick 1 and Pick 2. To pick, move the Graphic cursor to the desired location, wait for the tangent Autosnap marker to display and when it dose, press the left mouse button.

Step 6

Enter the CIRCLE command and the TTR option, as shown below, to insert the 2.5 inch diameter circle. (Figure Step 6A and 6B)

Command: CIRCLE

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: TTR

Specify point on object for first tangent of circle: P3 Specify point on object for second tangent of circle: P4 Specify radius of circle <1.0000>: 1.25

Command:

Figure Step 6A
Figure Step 6B
AUTHOR’S COMMENTS: Keep in mind that you do not enter the P3 or P4 on the keyboard. They simply mean Pick 3 and Pick 4 of this workalong.

Step 7

Enter the CIRCLE command and the TTR option, as shown below, to insert the middle 2 diameter circle. (Figure Step 7A and 7B)

Command: CIRCLE

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: TTR

Specify point on object for first tangent of circle: P5

Specify point on object for second tangent of circle: P6

Specify radius of circle <1.2500>: 1

Command:

Figure Step 7A
Figure Step 7B

Step 8

Save and close the drawing.

MUST KNOW: A very useful feature in AutoCAD is being able to undo a command or redo an undo. All of the commands in the current drawing session can be undone, one at a time. The last undo only can be reversed with a redo.To undo the last command, enter the U command, press CTRL+Z, or click the icon as shown in the figure on the right.

Command: U

If more then one U is entered, it will step back one command at time. This is useful if you made an error several commands earlier.

Command: U

Command: U

Command: U

Enter the REDO command, press CTRL+Y, or click the icon as shown in the figure on the right to redo the undo. The redo will undo the last undo only.

Command: REDO

Drafting Lesson: Reading Dimensions for Circles and Arcs

Circles and arcs are dimensioned as follows:

Circles are dimensioned with their diameter. For example: 2.0 DIA.

Arcs are dimensioned with their radius.

For example: 1.5 R

When there is more than one circle of the same diameter, it is only dimensioned once. For example: 0.5 DIA., 4 PLACES

Sometimes multiple arcs are dimensioned as typical (TYP.). For example: 2.0 R TYP. Typical simply means that there is at least one more arc of the same size. See Figure 7-8

Figure 7-8 Reading Dimensions

Key Principles

Key Principles in Module 7

  1. A circle is 360 degrees and can be divided into four quadrants.
  2. All points on a circle are at a given distance from is center point.
  3. An arc is defined as an open curve in which all points are the same distance from its center point.
  4. By default, AutoCAD draws arcs counterclockwise.
  5. When drawing arcs it is best to specify the center point first, the start point that sets the radius second, and an angle to locate the endpoint third.
  6. A very useful feature in AutoCAD is being able to undo a command or redo an undo.

Lab Exercise 7-1

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 07-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Object All lines, circles and arcs Red

Step 1

Start a new drawing using the template shown above.

Step 2

Save and name the drawing with the name shown above.

Step 3

Setup the layers using the Layering Scheme shown above.

Step 4

Draw the object shown in the figure. In this drawing, all objects should be on layer: Object and display red. (Figure Step 4A and 4B)

Figure Step 4A
Completed Drawing
Figure Step 4B

Step 5

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Inches.

Step 6

Check the drawing’s accuracy with the key.

Step 7

If there are any errors, turn layer: Key off and correct the drawing. If necessary, start a new drawing and draw it again.

Step 8

Turn layer Key on. If the drawing still inaccurate, go back to Step 7.

Step 9

Turn layer Key off.

Step 10

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hint. If you get stuck and cannot complete it on your own, use the following hint to help you.

Hint 1

(Figure Hint 1)

Figure Hint 1

Lab Exercise 7-2

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 07-2 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Object All lines, circles and arcs Red

Step 1

Start a new drawing using the template shown above.

Step 2

Save and name the drawing with the name shown above.

Step 3

Setup the layers using the Layering Scheme shown above.

Step 4

Draw the object shown in the figure. In this drawing, all objects should be on layer: Object and display red. (Figure Step 4A and 4B)

Figure Step 4A
Completed Drawing
Figure Step 4B

Step 5

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Millimeters.

Step 6

Check the drawing’s accuracy with the key.

Step 7

If there are any errors, turn layer Key off and correct the drawing. If necessary, start a new drawing and draw it again.

Step 8

Turn layer: Key on. If the drawing still inaccurate, go back to Step 7.

Step 9

Turn layer: Key off.

Step 10

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Draw the two circles using the TTR option. (Figure Hint 1)

Figure Hint 1

Hint 2

Draw the four smaller circles using the @ as shown below. (Figure Hint 2)

Figure Hint 2

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 85,170

Specify radius of circle or [Diameter]: D

Specify diameter of circle: 10

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @40,0

Specify radius of circle or [Diameter] <5.0000>:

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @0,20

Specify radius of circle or [Diameter] <5.0000>:

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @-40,0

Specify radius of circle or [Diameter] <5.0000>:

Command:

8

Module 8: Object Snap

Learning Outcomes

  1. Describe object snap, AutoSnap, and manual object snap modes.
  2. List the object snap modes for a line, a circle, and an arc.
  3. Apply the OSNAP command to set the object snap modes for AutoSnap.
  4. Describe how to enable and disable object snap and its importance when creating drawings.
  5. Use object snap to complete drawings.

Object Snap

Object snap allows you to immediately locate and attach to predefined object snap modes (locations) on existing drawing objects. All drawing objects have at least one object snap mode. In this module, the object snap modes for the drawing objects line, circle, and arc are taught. Many more will be taught throughout the AutoCAD 2D book.

Using object snap allows you to draw quickly and accurately using the existing geometry in the drawing. This is done without having to know the coordinate locations of those objects. Object snap is one of the most important features in any CAD system.

Study Figure 8-1, 8-2, and 8-3. They show the object snap modes and their locations for a line, a circle, and an arc. A line has 3 snap mode locations that can be snapped to while circles and arcs have 5 each. When requested, AutoCAD can find and snap to these exact locations.

Figure 8-1 Object Snap Modes for a Circle
Figure 8-2 Object Snap Modes for a Line
Figure 8-3 Object Snap Modes for an Arc

AutoSnap

AutoSnap is a visual aid to help you see and use object snap modes (locations) more efficiently. It allows you to set the object snap modes that AutoSnap will find automatically when object snap is enabled. Object snap can be enabled or disabled anytime by pressing F3. While a command is active, AutoSnap displays a marker and a tool tip when the cursor is moved over an object snap mode location that it has been set to find. In Figure 8-4, AutoSnap is indicating that it found the endpoint of the line. Note that the Graphic cursor does not have to be located exactly at the endpoint of the line. It only has to be close.

Figure 8-4

Geometry Lesson: Finding the Center of a Square or Rectangle

Using geometry, the center of a square or a rectangle can easily and accurately be located without knowing its size or doing any math. To do this, either one of the following methods can be used.

Method 1

Step 1

Draw a construction line between any two diagonal corners by snapping to the endpoints.

Step 2

The midpoint of the construction line that you inserted in Step 1 is the center of the square or rectangle.

Step 3

In this step, a circle is inserted at the midpoint of the line. The circle is located exactly in the center of the square or rectangle.

Method 1

Method 2

Step 1

Draw a line between the midpoints of two opposite sides of the rectangle or square.

Step 2

Draw another line between the midpoint of the other opposite sides of the rectangle or square.

Step 3

The midpoint of either line and the intersection of the two lines is the center of the rectangle or square. Actually, one line would have been enough to find the center.

Method 2

Geometry Lesson: Using Construction Objects

The best way to construct most drawings is to draw construction objects as an aid. There will be more and more drawings like this in future lab exercises. Construction objects are objects that are drawn by you to be used for construction only and will not be part of the finished drawing. It is important to save those objects for later use or to see how the construction was preformed.

From this point forward, in all workalongs and lab exercises, create a layer and name it Construction, color 253. Draw all construction objects on this layer and do not delete them. When you complete the drawing, freeze layer Construction. When required, simply thaw layer Construction to display the construction objects. See Figure 8-5. The drawing on the left has layer Construction thawed while the drawing on the right has layer Construction frozen.

Figure 8-5
Construction Objects
AUTHOR’S COMMENTS: Some drawings do not require any construction objects to be drawn while others have a lot.

Using Construction Objects

AUTHOR’S COMMENTS: There are many ways to draw using AutoCAD and it seems that each CAD operator has his/her own drawing method. There is no right or wrong way to draw as long as the drawing is complete and accurate. Layers are used extensively by companies to keep the drawings standardized and consistent within the company. Layers are also used when plotting the drawings to achieve lineweight as you will see later in the AutoCAD 2D book.

I recommend using a construction layer. The construction layer contains drawing objects that are used to construct the object being drawn but in the end are not part of the actual drawing itself.

After you complete the drawing, freeze the construction layer so it cannot be seen by others. If in the future, you have to make revisions to the drawing simply thaw the construction layer and use the construction objects. That means you do not have to redraw them, which will save you time. Some drawings do not have any construction objects while other have a lot of them.

As an AutoCAD instructor, it also help me to see how student’s are constructing drawings. This is especially true for online students. When I cannot observe a student drawing, I use the construction layer to help me see the student’s drawing techniques.

When I draw in AutoCAD, I draw all objects on the layer Construction and complete the drawing. After I complete the drawing, I change the layers of the objects I want to be part of the finished drawing. The objects that remain on layer Construction are the construction objects. There are many ways to draw and each person has to choose his/her method that works the best for them. As you work your way through the book, you will learn many techniques and drawing methods. Over time, you will develop your own method of drawing that suits you best

AutoCAD Command: OSNAP

The OSNAP command is used to open the Drafting Settings dialogue box which allows you to set object snap mode defaults for Autosnap. The function key F3 toggles osnap off and on.

Shortcut: OS

Tools Pull-down
Right click Status Bar
Left click Status Bar

WORKALONG: Using Object Snap

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 08-1.

Step 3

Create layer: Object, color red and layer: Construction, color 253. (Figure Step 3)

Figure Step 3

Step 4

Enter the OSNAP command to open Drafting Settings dialogue box.

Step 5

Step 4 will open the Drafting Settings dialogue box. Enable the Object Snap tab. In the Object Snap modes area, enable the modes to match the figure. Click OK to close the dialogue box. (Figure Step 5)

Figure Step 5
AUTHOR’S COMMENTS: Autosnap is now set to look for the object snap modes Endpoint, Midpoint, Center, Quadrant, Intersection, and Extension. These settings can be changed at anytime. I do not suggest enabling too many or all of the snap modes at one time as this may cause confusion when drawing.

Step 6

Enable object snap by pressing the function key F3. Notice how the Object Snap icon in the Status bar will display enabled as shown in Figure Step 6A. Press F3 again and note how the Object Snap icon displays disabled as shown in Figure Step 6B.

Figure Step 6A
Figure Step 6B

Step 7

Set layer: Construction as the current layer. (Figure Step 7)

Figure Step 7

Step 8

Using the dimensioned drawing as a reference, enter the LINE command and draw the 4 lines to form the outer rectangle. (Figure Step 8A and 8B)

Figure Step 8A
Figure Step 8B
AUTHOR’S COMMENTS: Since layer Construction is the current layer, the lines in your drawing should be colored gray.

Step 9

Press F3 to enable object snap. Check to ensure that it is enabled by checking its status in the Status bar.

Step 10

Enter the LINE command and move the cursor on the top horizontal line. Move it approximately to the midpoint of the line. When the AutoSnap marker displays the midpoint icon and the tool tip, pick it. Figure Step 10)

Figure Step 10

AUTHOR’S COMMENTS: Note that each object snap mode marker displays a different icon. For midpoint, it is a triangle.

Step 11

Move the cursor to the bottom horizontal line and do the same as Step 10. Press Enter to exit the command. You now have a vertical line from the midpoint of the top line to midpoint of the bottom line. (Figure Step 11A and 11B)

Figure Step 11A
Figure Step 11B

AUTHOR’S COMMENTS: Note that you do not have to have Graphic cursor exactly at the object’s snap mode location. As long as the AutoSnap marker is displayed when you pick it, AutoCAD will snap exactly to that location. It takes a little practice to using object snap.

Step 12

Enter the CIRCLE command. To locate the center of the circle, move the cursor to the midpoint of the vertical line that you drew in Step 11. When the midpoint icon and the tool tip displays, pick it. Enter a D, for diameter, and then 0.75 to complete the circle. (Figure Step 12A and 12B)

Figure Step 12A
Figure Step 12B

AUTHOR’S COMMENTS: The circle is located exactly in the center of the rectangle.

Step 13

Enter the LINE command and for the first point snap to the center of the circle. For the second point, snap to the endpoint in the top right corner. (Figure Step 13A, 13B, and 13C)

Figure Step 13A
Figure Step 13B
Figure Step 13C
USER TIP: The function key F3 toggles object snap enabled, or disabled. Although there are other ways to do this, try to get into the habit of using F3 as it will greatly improve your drawing speed.

Step 14

Repeat Step 13 three additional times to draw 3 lines from the center of the rectangle to each of the corners of the rectangle. (Figure Step 14)

Figure Step 14

Step 15

Enter the CIRCLE command. For the center location of the circle, snap to the midpoint of one of the diagonal lines. Enter the radius of 0.125 or the diameter of 0.25. (Figure Step 15A and 15B)

Figure Step 15A
Figure Step 15B

Step 16

Repeat Step 15 three times to draw a circle at the midpoint of each inclined line. (Figure Step 16)

Figure Step 16

Step 17

Enter the LINE command and for the first point, snap to the top quadrant of the top left circle. For the second point, snap to the top quadrant of top right circle. (Figure Step 17A, 17B, and 17C)

Figure Step 17A
Figure Step 17B
Figure Step 17C
AUTHOR’S COMMENTS: Zoom in on the drawing if you have to snap to the quadrant.

Step 18

Repeat Step 17 three additional times to draw 3 more lines. Ensure that you snap to the quadrant of the circle to locate the end of each line. (Figure Step 18)

Figure Step 18

Step 19

Without entering a command, individually select the objects that you want to reside on layer Object. While the objects are selected, pull down the Layer toolbar list and click layer: Object. After you select the name, click inside the Graphic window and then press Esc to clear the selected objects. (Figure Step 19A and 19B)

Figure Step 19A
Figure Step 19B
AUTHOR’S COMMENTS: The objects you selected in Step 19 should display red. If they do not display red, redo Step 19. This process is a little tricky so it may have to practice it a few times to complete it successfully.

Step 20

Pull down the layer list again and freeze layer: Construction. Your drawing is complete and should appear as shown in the figure. (Figure Step 20A and 20B)

Figure Step 20A
Figure Step 20B

Step 21

Save and close the drawing.

USER TIP: Whenever possible, disable object snap. When it is enabled at the wrong time during the drawing process, it can cause drawing problems. It is important to use object snap whenever necessary, but it is also important to disable it when you do not require it. It can be toggled enabled or disabled with the F3 key.

Manual Object Snap Modes

Object snap modes can be entered manually inside any command that uses them. This can be a handy feature for modes that are not used very often and are not enabled in AutoSnap. It also overrides the current settings to force AutoCAD to find the snap mode you entered. i.e.

Command: LINE

Specify first point: end of

(Inside the LINE command, you must start the next line at the end of an existing Line. Instead of using AutoSnap, enter the mode end on the keyboard to AutoCAD’s prompt. When a line is picked, AutoCAD will snap to the closest endpoint on that line.)

or

Command: CIRCLE

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: mid of

(In the CIRCLE command, the snap mode mid is entered and AutoCAD responds of. Pick an existing object and AutoCAD will snap to its midpoint.)

USER TIP: When manually entering object snap modes, the Object Snap toolbar can be used rather than typing the object snap modes. A tool tip will open as you pass your cursor over each icon to see which mode each one represents.
Object Snap Toolbar
Right Click Status Bar

 

Key Principles

Key Principles in Module 8

  1. Object snap is one of the most important features in any CAD system. Use object snaps to quickly and accurately draw using existing geometry in the drawing.
  2. The function key F3 toggles object snap between enabled or disabled.
  3. Use geometry and object snap rather than math to find the centers of squares or rectangles.
  4. Disable object snap when you are not using it.
  5. Draw construction objects on layer Construction and freeze that layer after you complete the drawing.
  6. You can override or force AutoCAD to snap to an object snap location on an object by manually entering the osnap mode in the command line.

Lab Exercise 8-1

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 08-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object 1 All lines and arcs Red
Object 2 All circles Blue

Step 1

Start a new drawing using the template shown above.

Step 2

Setup the layers using the Layering Scheme shown above.

Step 3

Draw the object shown in the figure using the layering scheme. In this drawing, place the lines and arcs on layer: Object 1 and the circles on layer: Object 2. Lines and arcs should display red and the circles should display blue. (Figure Step 3A and 3B)

Figure Step 3A
Figure Step 3B
Completed Drawing

Step 4

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Inches.

Step 5

Check the drawing’s accuracy with the key.

Step 6

If there are any errors, turn layer Key off and correct the drawing. If necessary, start a new drawing and draw it again.

Step 7

Turn layer Key on. If the drawing still inaccurate, go back to Step 6.

Step 8

Turn layer Key off.

Step 9

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Use object snap modes and snap to as many locations as possible rather then entering XY coordinates on the keyboard. (Figure Hint 1)

Command: ARC

Specify start point of arc or [Center]: C

Specify center point of arc: (end) P1

Specify start point of arc: (end) P2

Specify end point of arc or [Angle/chord Length]: A

Specify included angle: 60

Command:

Figure Hint 1

Hint 2

Use object snap modes and snap to as many locations as possible rather then entering XY coordinates on the keyboard. (Figure Hint 2)

Command: LINE

Specify first point: (end) P3

Specify next point or [Undo]: (end) P4

Specify next point or [Undo]:

Command:

Figure Hint 2

Hint 3

There should be two construction objects in this drawing. (Figure Hint 3)

Figure Hint 3

Lab Exercise 8-2

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 08-2 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object 1 All lines and arcs Red
Object 2 All circles Blue

Step 1

Start a new drawing using the template shown above.

Step 2

Setup the layers using the Layering Scheme shown above.

Figure Step 3A
Figure Step 3B
Completed Drawing

Step 3

Draw the object shown below using the layering scheme. In this drawing, place the lines and arcs on layer: Object 1 and the circles on layer: Object 2. The lines and arcs should display red and the circles blue. (Figure Step 3A and 3B)

Step 4

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Inches.

Step 5

Check your drawing with the key. The key name is the same as the drawing name.

Step 6

If you have any errors, turn layer Key off and correct your drawing. If you cannot correct it, start it over from the beginning.

Step 7

Turn layer Key on to check your drawing. If it is still inaccurate, go back to Step 6.

Step 8

Turn layer Key off and freeze layer: Construction

Step 9

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

The arcs on the corners can be drawn using the command shown below. (Figure Hint 1)

Command: ARC

Specify start point of arc or [Center]: C

Specify center point of arc: (end) P1

Specify start point of arc: @-1.5,0

(This sets the radius and the direction of the start point.)

Specify end point of arc or [Angle/chord Length]: (end) P2

Command:

(Repeat on the other three corners. Keep in mind that arcs are constructed counterclockwise in AutoCAD.)

Figure Hint 1

Hint 2

The arcs on the sides can be drawn using the command shown below. (Figure Hint 2)

Command: ARC

Specify start point of arc or [Center]: C

Specify center point of arc: (mid) P3

Specify start point of arc: (mid) P4

Specify end point of arc or [Angle/chord Length]: (mid) P5

(Do the same on the other side. Ensure that you construct the arc counterclockwise.)

Command:

Figure Hint 2

Hint 3

The figure shows the construction objects in this drawing. (Figure Hint 3)

Figure Hint 3

Lab Exercise 8-3

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 08-3 N/A Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object 1 All lines and arcs Red
Object 2 All circles Blue

Step 1

Open the drawing: AutoCAD 2D Lab 08-2.

Step 2

Using the SAVEAS command, save it with the name: AutoCAD 2D Lab 08-3.

Step 3

Turn off all the layers except for layer: Key. If the magenta key from Lab 08-2 displays, select it and press the delete key. Turn all of the other layers back on.

Step 4

Complete the object by adding and erasing objects to match the figure. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 4B
Completed Drawing

Step 5

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Inches.

Step 6

Check your drawing with the key. The key name is the same as the drawing name.

Step 7

If you have any errors, turn layer Key off and correct them.

Step 8

Turn layer Key off and freeze layer Construction

Step 9

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

 

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Locate the larger circle as shown in the figure. (Figure Hint 1)

Figure Hint 1

Hint 2

Locate the smaller circle as shown in the figure. (Figure Hint 2)

Figure Hint 2

Hint 3

The figure shows the construction objects in this drawing. (Figure Hint 3)

Figure Hint 3

Lab Exercise 8-4

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 08-4 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Gasket All drawing objects Blue

Step 1

Draw the top view of the simple gasket shown in the dimensioned drawing using the layering scheme. (Figure Step 1A, 1B, and 1C)

Figure Step 1A
Simple Gasket
Figure Step 1B
Figure Step 1C
Completed Drawing

Step 3

Set the insertion units and check your drawing with the key. Turn layer Key off and freeze layer Construction.

Step 4

Save and close the drawing.

9

Module 9: Controlling the Drawing

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe the drawing terms; limits, extents, scale, units, and regeneration.
  2. Apply the ZOOM, PAN, REGEN, and VIEWRES commands and explain how you use them to control the drawing.

Controlling the Drawing

To control the drawing and improve your drawing speed, it is important for you to understand the drawing terms; limits, extents, scale, units, and regeneration and how they relate to the current drawing.

Drawing Limits

An AutoCAD drawing has an unlimited amount of model space available to draw in. The drawing limits are a user defined rectangular or square shape of 2D model space. The size of the drawing limits can be changed, as required, at anytime.

Drawing limits were important before layouts were added to AutoCAD in AutoCAD 2000. They are not that important to AutoCAD 2000 and newer users but are still part of the software.

Figure 9-1 The Drawing Limits

Drawing Extents

The drawing extents is defined as the smallest rectangle that will fit around all existing drawing objects in the current drawing that are visible (on a thawed layer). It is possible to draw outside the drawing limits and therefore objects that are outside the limits may not be visible in the normal drawing display. By being able to display the drawing extents, all visible (thawed) drawing objects that exist in the current drawing will display in the Graphic window. Being able to display the drawing extents is very important.

Since Model space is very large, objects are sometimes placed, by accident, somewhere out in space. If this happens in a drawing, it can severely derogate the performance of the drawing. Sometimes the only way to work on a drawing that is derogated is to find the erroneous objects and delete them. They can easily be found by displaying the drawing extents.

Figure 9-2 The Drawing Extents

Drawing Scale

The general rule for all AutoCAD drawings is to always draw the object at full scale or full size. Scaling is done in the viewports in the layouts. This is taught in Module 18.

Drawing Units

AutoCAD drawings are unitless. If a unit of 1 is entered into a drawing and the units selected by the creator for that drawing are inches, then 1 means 1 inch. From that point forward all units entered into that drawing must be entered as inches. In another drawing, the operator creating the drawing picks the units to be millimeters. All numbers entered in that drawing must be entered in millimeters.

To sum up, when a drawing is first started, the creator must make a decision as to what units will be used for that drawing. From that point on, all numbers entered into that drawing must be entered in those units.

Zooming

Zooming is the process of moving the drawing objects closer or further away from your eyes without actually changing the size of the objects or their location in model or paper space. It is an important tool for you and is used extensively in the drawing process. Drawings can be very large and therefore you must be able to zoom in to be able to see in greater detail and zoom out again to work on the overall drawing.

The most efficient method to zoom a drawing is to locate the Graphic cursor in the center of the area to be zoom and then rotate the wheel on the mouse forward or backward. While the AutoCAD command ZOOM can be also used to zoom the drawing, using the wheel to zoom will greatly increase your drawing speed.

Panning

Panning is the process of moving the existing drawing objects around the Graphic window without actually physically moving any of the drawing object’s current location in model or paper space.

The most efficient method to pan a drawing is with the wheel on the mouse. Press and hold the wheel down and them move the mouse to pan the drawing. A Pan Hand cursor will replace the Graphic cursor when you hold the mouse wheel down. While the AutoCAD command PAN can be used to pan the drawing, using the wheel will greatly increase your drawing speed.

Regenerating the Drawing

AutoCAD stores all existing drawing objects and their properties in a database format in the .dwg file. When a drawing is opened, AutoCAD reads the .dwg file and constructs the drawing objects, one at time, displaying them in the Graphic window.

There are times when working on a drawing that it must be reconstructed from the .dwg file. This is called regeneration. The command used to do this is REGEN. There are many reasons for regeneration and they will become clear in future modules. Since some commands do not automatically regenerate, it is up to you to manually execute the REGEN command to force the display of any changes that happened when those commands was executed.

AutoCAD Command: ZOOM

The ZOOM command is used to move the existing drawing objects closer or farther away from the user’s eyes without changing the drawing object’s physical size.

Shortcut: Z

View Pull-down
Zoom Toolbar
Zoom Toolbar

AUTHOR’S COMMENTS: If you have a mouse with a wheel as the center button, you can use it to zoom in and out of your drawing by first locating the Graphic cursor in the center of the area to be zoomed and then rotating the wheel forward or backward. While the AutoCAD command ZOOM can be used to zoom the drawing using the wheel will greatly increase your drawing speed. If you don’t have a wheel mouse, you must use the ZOOM command and its options to accomplish the same thing.

AutoCAD Command: PAN

The PAN command is used to move the drawing objects around the Graphic window without

physically moving them.

Shortcut: P

View Pull-down
Standard Toolbar

AUTHOR’S COMMENTS: If you have a mouse with a wheel as the center button, you can use it to pan your drawing by holding wheel down and moving the mouse. While the AutoCAD command PAN can be used pan the drawing using the wheel will greatly increase your drawing speed. If you don’t have a wheel mouse, you must use the PAN command and its options to accomplish the same thing.

AutoCAD Command: LIMITS

The LIMITS command is used to set the drawing limits.

Shortcut: none

Format Pull-down

AutoCAD Command: REGEN

The REGEN command is used to reconstruct the drawing objects from the .dwg file and display them in the Graphic window.

Shortcut: RE

View Pull-down

AutoCAD Command: VIEWRES

The VIEWRES command sets the number of vectors that AutoCAD uses when it displays circles

and arcs in the Graphic window.

Shortcut: none

MUST KNOW: AutoCAD drawings are unitless. The creator of the drawing makes the decision of what units will be used for that drawing. From that point forward, all numbers entered in that drawing must be in those units.
MUST KNOW: The general rule for all AutoCAD drawings is to draw the object at full scale or full size. Scaling is done in the viewports in the layouts.
AUTHOR’S COMMENTS: The only objects AutoCAD can construct in any drawing are lines and points. Circles and arcs are constructed using many lines connecting two XY coordinate points that are calculated each time the drawing is regenerated. The more lines AutoCAD uses to construct the circles and arcs, the smoother or more circular they will display. The VIEWRES command sets the zoom percentage of the lines that AutoCAD uses when it constructs or regenerates the circles and arcs in the drawing. When VIEWRES is set to 20000, the maximum, the circles and arcs will appear very smooth. On the other hand, it will take AutoCAD much longer to calculate that many points for each circle and arc in the drawing. You have to take all of this into account when you are setting the viewres for the drawing.

WORKALONG: Using the LIMITS, ZOOM, PAN, REGEN, and VIEWRES Commands

Step 1

Open the drawing: AutoCAD 2D Workalong 08-1.

Step 2

Using the SAVEAS command, save the drawing with the name: AutoCAD 2D Workalong 09-1.

Step 3

Enter the ZOOM Extents command, as shown below. The drawing should appear as shown in the figure. (Figure Step 3)

Command: ZOOM

Specify corner of window, enter a scale factor (nX or nXP), or

[All/Center/Dynamic/Extents/Previous/Scale/Window/Object] <real time>: E

Command:

Figure Step 3

AUTHOR’S COMMENTS: I find it easier to enter the ZOOM Extents command on the keyboard. It is fast if you use the shortcuts Z and E.

Step 4

Practice zooming the drawing in and out by rotating the wheel on the mouse.

Step 5

Move the crosshairs to approximately the center of the object and push the middle wheel down and hold it. A Hand icon will replace the crosshairs. While holding the wheel down, pan the drawing around.

Step 6

Enter the ZOOM Extents command to zoom the drawing to its extents. Step 7 Enter the LIMITS command, as shown below, to set the drawing limits.

Command: LIMITS

Reset Model space limits:

Specify lower left corner or [ON/OFF] <0.0000,0.0000>:

Specify upper right corner <12.0000,9.0000>: 8.5,11

Command:

AUTHOR’S COMMENTS: It is always best to set the lower left corner of the drawing limits to 0,0. Doing that, help keeps the drawing objects in the positive quadrant. In other words, both X and Y are positive.

Step 8

Use the CIRCLE command, as shown below, to draw a 1 diameter circle with its center at X20,Y22.

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 20,22

Specify radius of circle or [Diameter]: D

Specify diameter of circle: 1

Command:

Step 9

Enter the ZOOM Extents command. Your drawing should appear as shown in the figure. (Figure Step 9)

 

Figure Step 9

Step 10

Use the CIRCLE command, as shown below, to draw a 1 diameter circle with its center at X-35,Y-35.

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: -35,-35

Specify radius of circle or [Diameter]: D

Specify diameter of circle: 1

Command:

Step 11

Enter the ZOOM Extents command. Your drawing should appear as shown in the figure. (Figure Step 11)

Figure Step 11
AUTHOR’S COMMENTS: Notice how the ZOOM Extents command zooms the drawing so that it displays all of the existing objects in the drawing.

Step 12

Delete the two circles that you inserted in Steps 8 and 10. Enter the ZOOM Extents command again. The drawing should match the figure. (Figure Step 12)

Figure Step 12

Step 13

Enter the VIEWRES and REGEN commands, as shown below. (Figure Step 13)

Command: VIEWRES

Do you want fast zooms? [Yes/No] <Y>: Y

Enter circle zoom percent (1-20000) <2000>: 20000

Command: REGEN

Regenerating model

Figure Step 13

AUTHOR’S COMMENTS: Always answer Yes to fast zooms in the VIEWRES command. The circles will now display using 20,000 vectors. Since the VIEWRES command does not automatically regenerate the drawing, the REGEN must be executed after it to reconstruct the drawing objects to display the new resolution.

Step 14

Save and close the drawing.

USER TIP: Since the ZOOM Extents command is used a lot during the drawing process, there is a shortcut to execute this command. Move the cursor to somewhere on the Graphic window and double click the wheel or middle button on the mouse.When attempting to find all the existing objects by displaying the drawing extents, ensure that all layers are thawed and on.

USER TIP: If you have a mouse with a wheel as the center button, use it to zoom in and out of the drawing by rotating the wheel forward or backward. Using the wheel to zoom, rather than commands, will increase your drawing speed. If your computer is not equipt with a wheel mouse, you must use the ZOOM command.The wheel can also be used to pan the drawing. Move the crosshairs to the part of the drawing to be panned and press down on the wheel. A Pan Hand icon will display as the Graphic cursor. While holding down the wheel, move the mouse to pan the drawing. Using the wheel to pan will also increase your drawing speed. If your computer does not have mouse with a center wheel, you must use the PAN command.
MUST KNOW: At times, the current drawing must be regenerated from the .dwg file. Drawing regeneration is accomplished with the REGEN command. If you are in doubt about the current appearance of the drawing, you should regenerate it.

USER TIP: The ZOOM Previous command allows you to step back through the previous zoomed states. This allows you to quickly zoom in on an object, draw or edit, and then return back to the previous zoomed state.

Zoom Previous
View Pull-down
USER TIP: The ZOOM Extents command is a very important command and if used when required, can prove to save you a lot of time and effort. When you are opening a drawing for the first time, especially one that was drawn by someone other than you, the first thing you should do is to ensure that all layers are on and thawed. Then execute the ZOOM Extents command. Doing this will display all existing drawing objects in the Graphic window which will show you the size and scope of the drawing before you begin working on it.
AUTHOR’S COMMENTS: Do not use a calculator to complete any lab exercise in the AutoCAD 2D book. By using geometry principles, drawing techniques, object snapping, and construction objects, AutoCAD will do all the math for you.

Key Principles

Key Principles in Module 9

  1. The drawing extents is the smallest rectangle that will fit around all the existing drawing objects in the drawing.
  2. Always draw all objects in Model space at full size or full scale.
  3. AutoCAD drawings are unitless. The operator who creates the drawing makes the decision what units will be used for that drawing.
  4. When a drawing is regenerated, AutoCAD reconstructs the drawing from the .dwg file. Drawings regenerate when they are opened but you can force an open drawing to regenerate with the REGEN command.

Lab Exercise 9-1

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 09-1 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Setup the layers using the Layering Scheme shown above.

Step 2

Draw the object shown in the figure using the layering scheme. (Figure Step 2A, 2B, and 2C)

Figure Step 2A
AUTHOR’S COMMENTS: Do not use a calculator to complete this lab exercise or any other lab exercise in the AutoCAD 2D book. By using geometry principles, drawing techniques, object snapping, and construction objects, AutoCAD will do all the math for you.
Figure Step 2B
Completed Drawing
Figure Step 2C
Detail

Step 3

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Millimeters.

Step 4

Check the drawing’s accuracy with the key.

Step 5

If there are any errors, turn layer Key off and correct the drawing.

Step 6

Turn layer: Key on. If the drawing still inaccurate, go back to Step 7.

Step 7

Turn layer: Key off.

Step 8

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

See the figures. (Figure Hint 1A and 1B)

Figure Hint 1A
Figure Hint 1B

Hint 2

Construction lines for circle B. (Figure Hint 2)

Figure Hint 2

Hint 3

Construction to draw circle D. (Figure Hint 3)

Figure Hint 3

Hint 4

Construction objects in the drawing. (Figure Hint 4)

Figure Hint 4
Construction Lines

Lab Exercise 9-2

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 09-2 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Setup the layers using the Layering Scheme shown above.

Step 2

Draw the object shown in the figure using the layering scheme. (Figure Step 2A and 2B)

AUTHOR’S COMMENTS: This is a very small object. You will have to zoom in to work on it.
Figure Step 2A
Figure Step 2B
Completed Drawing

AUTHOR’S COMMENTS: Do not use a calculator to complete this lab exercise or any other lab exercise in the AutoCAD 2D book. By using geometry principles, drawing techniques, object snapping, and construction objects, AutoCAD will do all the math for you.

Step 3

Set the viewres to 10,000 and regenerate your drawing.

Step 4

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Inches.

Step 5

Check your drawing with the key. The key name is the same as the drawing name.

Step 6

If you have any errors, turn layer: Key off and correct your drawing.

Step 7

Turn layer: Key on to check your drawing. If it is still inaccurate, go back to Step 7.

Step 8

Turn layer: Key off and freeze layer: Construction.

Step 9

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Draw two construction lines from end of arc to end of arc as shown in the figure. (Figure Hint 1)

Figure Hint 1

Hint 2

Draw two circles locating their centers at the midpoint of the construction lines that you drew in Hint Step 1. Construction an arc from center of the circle on the right side to the center of the circle on the left side. Draw a circle at the midpoint of the arc. (Figure Step Hint 2)

Figure Hint 2

Hint 3

Erase the construction arc you drew in Hint Step 2. Draw a construction arc from the center of the circle to the center of the circle. Draw a circle at the midpoint of the arc. You will have to repeat this three more times. (Figure Hint 3A and 3B)

Figure Hint 3A
Figure Hint 3B

Hint 4

Insert four construction lines from the end of arc to the end of arc. Draw a construction line from the midpoint of line to midpoint of line on both sides. (Figure Hint 4)

Figure Hint 4

Hint 5

Draw a circle at the midpoint of the line on both sides. Erase the construction line and draw a new construction line from the quad of the circle to the midpoint of the line. It is important to draw from the quad to the midpoint. Insert a circle at the midpoint of the line. Erase the construction line and repeat as shown in the figures. (Figure Hint 5A and 5B)

Figure Hint 5A
Figure Hint 5B

10

Module 10: Drawing Lines Using Polar Coordinates

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe the geometry of angles.
  2. Describe the Polar Coordinate System.
  3. Apply the LINE command to draw lines using the Polar Coordinate System.

Geometry Lesson: Angles

An angle is formed by two intersecting lines. When measuring an angle in a drawing, AutoCAD defines zero degrees at 3:00 o’clock with the positive angle in the counterclockwise direction and a negative angle in the clockwise direction. Study angle geometry in Figure 10-1, 10-2, and 10-3. These principles are used extensively to construct drawings in AutoCAD.

Figure 10-1 Angles – Part 1
Figure 10-1 Angles – Part 2

All angles are express in either positive or negative degrees. AutoCAD will accept either. Since positive is the default, the positive sign does not have to precede the number but a negative angle must be preceded by the negative sign.

Figure 10-3 Angles – Part 3

WORKALONG: Working With Angles

Step 1

Study Figure 10-1, 10-2, and 10-3. Using what you learned and without drawing in AutoCAD, find the answers for the angles A to M. After you find a solution to all of the angles, check your answers with the solutions at the end of the module.

 

Figure Step 1A
Figure Step 1B
Figure Step 1C

AUTHOR’S COMMENTS: It is sometime easier to sketch the figure and calculate the angle using paper and pencil.

Figure Step 1D
Figure Step 1E
Figure Step 1F
Figure Step 1G

The Polar Coordinate System

The Polar Coordinate System is a two-dimensional coordinate system in which each point on a plane is determined by a distance from a reference point and an angle from a reference direction. In AutoCAD, you use it when you are given a distance and an angle from a known coordinate location. All angles are measured with 0 degrees at 3:00 o’clock. The angles are positive in the counterclockwise direction and negative in the clockwise direction. See Figure 10-4.

Figure 10-4 The Polar Coordinate System

A polar coordinate is entered into AutoCAD as a distance, a less than symbol, and an angle. In all cases, the @ symbol must precede the distance. i.e.

@6<45

means ‘ from the last point, go 6 units at an angle of 45 degrees, positive, starting at 3 o’clock ‘. AutoCAD always assumes positive as default, therefore, the positive sign can be omitted. i.e.

@5<-60

WORKALONG: Using the Polar Coordinate System – Part 1

Workalong and complete the following steps to solve the angles and polar coordinates. If necessary, use paper and pencil. Do not use AutoCAD.

Step 1

Study the figure and solutions for numbers 1 to 6. Solve the answers for numbers 7 to 11. (Figure Step 1)

Figure Step 1

AUTHOR’S COMMENTS: The answers are at the end of the module. Do not look at the answers until you think you have correctly solved each one.

Object A Solution:

1. Find the polar coordinate A TO B: @2<0
2. Calculate the first angle: 180 – 150 = 30 degrees
3. Find the polar coordinate B TO C: @2<30
4. Copy the 30 degree angle to the next corner.
5. Calculate the second angle: 180 – 110 = 70 degrees
6. Add the two angles: 30 + 70 = 100
7. Find the polar coordinate C TO D: @ <
8. Copy the angle 100 to the next corner.
9. Calculate angle DD: DD =
10. Find angle EE: EE =
11. Find the polar coordinate D TO E: @ <

Step 2

Study the figure and find the solutions for numbers 1 to 11. (Figure Step 3)

Figure Step 2

AUTHOR’S COMMENTS: The answers are at the end of the module. Do not look at the answers until you think you have correctly solved each number.

Object B Solution:

1. Find polar coordinate A TO B @ <
2. Calculate angle AA:
3. Find polar coordinate B TO C @ <
4. Copy angle AA to the next corner
5. Calculate angle BB
6. Find angle CC
7. Find polar coordinate C TO D @ <
8. Copy angle CC to the next corner
9. Calculate angle DD
10. Find angle EE
11. Find polar coordinate D TO E @ <

WORKALONG: Using the Polar Coordinate System – Part 2

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 10-1.

Step 3

Create layers: Object and Construction. (Figure Step 3)

Figure Step 3

Step 4

Set layer: Object as the current layer and enter the LINE command, as shown below, to draw the object. (Figure Step 4A)

Figure Step 4A

Command: L

Specify first point: 2.5,4.5

(Start with an absolute Cartesian Coordinate.)

Specify next point or [Undo]: @3<0

(A to B is a horizontal line which is zero degrees.)

Specify next point or [Undo]: @2<90

(B to C is a vertical line at 90 degrees.)

(Figure Step 4B)

Figure Step 4B

AUTHOR’S COMMENTS: Refer to the dimensioned drawing in Figure Step 4 when you construct this drawing and try to understand the polar coordinates that you are entering.

Specify next point or [Close/Undo]: @2<45

(C to D is 45 degrees positive.)

(Figure Step 4C)

Figure Step 4C

Specify next point or [Close/Undo]: @1.5<100

(D to E)

(Figure Step 4D)

Figure Step 4D

Specify next point or

[Close/Undo]: @1<180

(E to F is a horizontal line at 180 degrees.)

(Figure Step 4E)

Figure Step 4E
MUST KNOW: AutoCAD measures angles starting with 0 degrees at 3:00 o’clock. Positive angles are measured in the counterclockwise direction and negative angles are measured in the clockwise direction.

Specify next point or [Close/Undo]: @2<225

(F to G)

(Figure Step 4F)

Figure Step 4F

Specify next point or [Close/Undo]: @1.5<165

(G to H)

Specify next point or [Close/Undo]: C

(Use Close for H to A)

Specify next point or [Close/Undo]:

Command:

(Figure Step 4G)

Figure Step 4G

Step 5

Your completed drawing should match the figure. (Figure Step 5)

Figure Step 5

Step 6

Save and close the drawing.

Figure 10-5 Object Snap Mode – Intersection

WORKALONG: Using the Object Snap Mode – Intersection

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 10-2.

Step 3

Create the layers: Object and Construction. Set layer: Construction as the current layer. (Figure Step 3)

Figure Step 3
Figure Step 4A

Step 4

Refer to the figures and enter the LINE command, as shown below, to draw four construction lines. (Figure Step 4A and 4B)

Command: L

LINE Specify first point: 2,5

Specify next point or [Undo]: @4<0

Specify next point or [Undo]: @2<90

Specify next point or [Close/Undo]: @1<90

Specify next point or [Close/Undo]: @3<180

Specify next point or [Close/Undo]: @1<180

Specify next point or [Close/Undo]: @1<270

Specify next point or [Close/Undo]: C

Figure Step 4B

AUTHOR’S COMMENTS: Note how I drew the rectangle by drawing lines from endpoint to endpoint of the object’s geometry. This workalong is teaching you a drawing technique that will help you improve your drawing speed.

Step 5

Ensure that osnap is enable and then draw an additional construction line by snapping to the endpoint of the existing line and 1 unit in the -X direction. (Figure Step 5A and 5B)

Figure Step 5B
Figure Step 5B

AUTHOR’S COMMENTS: As I commented in Step 4, I drew the rectangle by drawing lines from endpoint to endpoint of the object’s geometry. In this step, I can now snap to endpoint of line that is 2 inches long. Even though you cannot see the endpoint of the line, osnap will find it easily by move the graphic cursor over the line.

Step 6

Set layer: Object as the current layer. Enter the LINE command and enable osnap. Draw the perimeter lines of the object by snapping to the endpoints of the construction lines. (Figure Step 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H, and 6J)

Figure Step 6A
Figure Step 6B
Figure Step 6C
Figure Step 6D
Figure Step 6E
Figure Step 6F
Figure Step 6G
Figure Step 6H
Figure Step 6J

Step 7

On layer: Construction , draw two construction lines by snapping to the endpoint of the existing lines as shown in the figure. (Figure Step 7)

Figure Step 7

Step 8

Enter the CIRCLE command and draw a 1 diameter circle locating its center point by

snapping to intersection of the two construction lines you drew in Step 7. (Figure Step 8A and 8B)

Figure Step 8A
Figure Step 8B

Step 9

Freeze layer: Construction. (Figure Step 9)

Figure Step 9

Step 10

Save and close the drawing.

Key Principles

Key Principles in Module 10

  1. The Polar Coordinate System is used to draw lines using a distance and an angle from a known coordinate location.
  2. By default, an AutoCAD polar coordinate measures angles starting 0 degrees at 3:00 o’clock.
  3. In a polar coordinate, positive angles are measured counterclockwise and negative angles are measured clockwise.
  4. A polar coordinate is entered into AutoCAD as a distance, a less than symbol, and an angle. In all cases, the @ symbol must precede the distance.

Lab Exercise 10-1

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 10-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object Lines Red

Step 1

Start a new drawing using the template shown above.

Step 2

Setup the layers using the Layering Scheme.

Step 3

Draw the object shown in the figures using the layering scheme. (Figure Step 3A and 3B)

Figure Step 3A

 

Fig Step 3B
Completed Drawing

Step 4

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Inches.

Step 5

Check your drawing with the key. The key name is the same as the drawing name.

Step 6

If you have any errors, turn layer: Key off and correct your drawing. If you cannot correct it, start it over from the beginning.

Step 7

Turn layer: Key on to check your drawing. If it is still inaccurate, go back to Step 6.

Step 8

Turn layer: Key off.

Step 9

Save and close the drawing.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and can not complete it on your own, use the following hints to help you.

Hint1

See the figure for the polar coordinates. (Figure Hint 1)

Figure Hint 1

Hint 2

Draw the line from J to I by snapping to the endpoints. (Figure Hint 2)

Figure Hint 2

Hint 3

The solutions to the angles at G and F are shown in the figures. (Figure Hint 3A and 3B)

Figure Hint 3A

 

Figure Hint 3B

Lab Exercise 10-2

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 10-2 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object Lines Red

Step 1

Start a new drawing using the template shown above.

Step 2

Setup the layers using the Layering Scheme.

Step 3

Draw the object shown in the figures using the layering scheme. (Figure Step 3A and 3B)

Figure Step 3A
Figure Step 3B
Completed Drawing

Step 4

Enter the UNITS command. In the Units dialogue box, set the Insertion Units to Millimeters.

Step 5

Check your drawing with the key. The key name is the same as the drawing name.

Step 6

If you have any errors, turn layer: Key off and correct your drawing. If you cannot correct it, start it over from the beginning.

Step 9

Save and close the drawing.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hint. If you get stuck and cannot complete it on your own, use the following hint to help you.

Hint 1

See the figure for the polar coordinates. (Figure Hint 1)

Figure Hint 1

Lab Exercise 10-3

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 10-3 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Angle Bracket All drawing objects Blue

Step 1

Draw the front view of the angle bracket shown in the dimensioned drawing using the layering scheme. (Figure Step 1A, 1B, and 1C)

Step 2

All objects should be on layer Angle Bracket and display blue.

 

Figure Step 1A
Angle Bracket
Figure Step 1B
Figure Step 1C
Completed Drawing

Step 3

Set the insertion units and check your drawing with the key. Turn layer: Key off and freeze layer: Construction.

Step 4

Save and close the drawing.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints.

Hint 1

This figure shows my construction drawing objects. Your construction drawing objects do not have to match as there are may ways to construct an object. I use circles rather an arcs, whenever possible, as they are easier to construct. (Figure Hint 1)

 

Figure Hint 1

Angle A = 40 degrees

Angle B = 125 degrees

Angle C = 150 degrees

Angle D = 30 degrees

Angle E = 215 degrees

Angle F = 35 degrees

Angle G = 75 degrees

Angle H = 105 degrees

Angle J = 135 degrees

Angle K = 120 degrees

Angle L = 211 degrees

Angle M = 324 degrees

Object A Solution:

1.      Find the polar coordinate A TO B: @2<0
2.       Calculate the first angle: 180 – 150 = 30 degrees
3.       Find the polar coordinate B TO C: @2<30
4.     Copy the 30 degree angle to the next corner.  
5.       Calculate the second angle: 180 – 110 = 70 degrees
6.       Add the two angles: 30 + 70 = 100 degrees
7.       Find the polar coordinate C TO D: @3<100
8.       Calculate angle DD: 180 – 100 = 80 degrees
9.       Find angle EE: 100 + 80 = 180 degrees
10.   Find the polar coordinate D TO E: @2<180

Object B Solution:

1.       Find polar coordinate A TO B @3<0
2.       Calculate angle AA: 180 – 135 = 45 degrees
3.       Find polar coordinate B TO C @3<45
4.   Copy angle AA to the next corner  
5.       Calculate angle BB 180 – 105 = 75 degrees
6.       Find angle CC 45 + 75 = 120 degrees
7.       Find polar coordinate C TO D @2<120
8.  Copy angle CC to the next corner  
9.       Calculate angle DD 180 – 120 = 60 degrees
10. Find angle EE120 + 60 = 180 degrees  
11.   Find polar coordinate D TO E @3<180

 

11

Module 11: Competency Test 2 Open Book

Learning Outcomes

When you have completed this module, you will be able to:

  1. Within a one-hour time limit, complete a written exam and a lab exercise without the aid of a key.

The AutoCAD 2D book was written with competency based modules. What that means is that you have not completed each module until you have mastered it. The Competency Test module contains multiple choice questions and a comprehensive lab exercise to test your mastery of the set of modules that you completed. There are no answers or keys supplied in a Competency Test module since it is meant to be checked by your instructor. If there are any parts of this module that you have trouble completing, you should go back and reread the module or modules containing the information that you are having trouble with. If necessary, redo as many lab exercises required until you fully understand the material.

If you are Completing this book:

Multiple Choice Questions

Select the BEST answer.

  1. What object snap mode is used to snap to the center point of a line?
    1. Halfpoint
    2. Center
    3. Quadrant
    4. Midpoint
    5. Endpoint
  2. What scale should almost all objects be drawn in an AutoCAD drawing?
    1. 1:50
    2. 1:10
    3. 1:2
    4. Full Scale
    5. You don’t draw in scale in AutoCAD
  3. What is the name of the visual aid that helps the user locate object snap modes more efficiently?
    1. Snapmode
    2. AutoSnap
    3. SnapAuto
    4. AutoCADSnap
    5. AutoMode
  4. What coordinates are the best to set the lower left corner of the limits of the drawing?
    1. 0,0
    2. 2,2
    3. 4,4
    4. 6,6
    5. 8,8
  5. What is the smallest rectangle that will fit around all of the existing objects in the drawing called?
    1. The drawing border
    2. The drawing grid
    3. The drawing mode
    4. The drawing extents
    5. The drawing size
  6. What command sets the number of vectors that AutoCAD uses when it regenerates circles and arcs?
    1. VIEWRES
    2. REGEN
    3. CIRCLE
    4. ARC
    5. VIEW
  7. What function key toggles Autosnap on and off?
    1. F1
    2. F2
    3. F3
    4. F4
    5. F5
  8. What is the name of the four object snap mode locations that are located around the circumference of a circle?
    1. Center
    2. Midpoint
    3. Endpoint
    4. Points
    5. Quadrants
  9. Which one of the following best describes the polar coordinate @10<125?
    1. From the last point, go 12.5 units at an angle of negative 10 degrees
    2. From the last point, go 10 units at an angle of negative 125 degrees
    3. From the last point, go 125 units at an angle of positive 10 degrees
    4. From the last point, go 10 units at an angle of positive 125 degrees
    5. From the last point, go 125 units at an angle of negative 10 degrees
  10. What polar coordinate would draw the same angle as @5<225?
    1. @5<-125
    2. @5<-225
    3. @5<-135
    4. @5<-145
    5. @5<-165

Lab Exercise 11-1 OPEN BOOK

Drawing Name Template Units
AutoCAD 2D Lab 11-1 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object Line, circle and arcs Red

Step 1

Setup the layers using the Layering Scheme shown above.

Step 2

Draw the object shown in the figure using the layering scheme. (Figure Step 2A and 2B)

Figure Step 2A
AUTHOR’S COMMENTS: Do not delete the construction lines.

 

Figure Step 2B

Step 3

Draw all construction objects on layer: Construction.

AUTHOR’S COMMENTS: Draw the construction lines (shown as dashed lines in the drawing for clarity) by snapping to the endpoints of the lines, endpoint of the 60 radius arc and the center of the 5 diameter circle. Locate the 10 diameter circles with their center located at the intersections of the construction lines.

Step 4

When complete, freeze layer: Construction.

Step 5

Save and close the drawing.

AUTHOR’S COMMENTS: There is no key for this lab.

III

Part 3

12

Module 12: Fillets

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe tangency and explain how to locate the point of tengency.
  2. Describe a fillet.
  3. Apply the FILLET command to construct fillets between two drawing objects.
  4. Describe the object snap mode Tan.
  5. Apply the LINE command using the object snap mode Tan to draw lines tangent to arcs and circles.

Geometry Lesson: Tangency

A point of tangency is the theoretical point where a line joins an arc, two arcs join each other, or two circles join each other making a smooth transition. A line is tangent to a circle or an arc when it passes touching only one point on the circle or arc. The tangent point is located where a line drawn perpendicular from the center of the circle or arc touches the line. Study Figure 12-1.

Figure 12-1
Tangency – Part 1

A fillet is a tangent arc. A tangent arc must be tangent at both ends where it connects to existing lines or arcs. Figure 12-2 shows five examples of fillets.

Figure 12-2
Tangency – Part 2

AutoCAD Command: FILLET

The FILLET command is used to draw a tangent arc. It inserts an arc tangent to the two existing

drawing objects selected in the command.

Shortcut: F

Modify Toolbar
Modify Pull-down
Home Ribbon

WORKALONG: Using the FILLET Command

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 12-1.

Step 3

Create layers: Object and Construction. Set layer: Object as the current layer.

Figure Step 4A

Drawing Outside the Box

AUTHOR’S COMMENTS: Up to this point in the book, you have been drawing lines knowing the exact location and length of the lines. In this module, you will learn how to draw lines without knowing their exact length. You must know the exact start point of the line and the line’s direction. You guess at its length either drawing it longer or shorter than its actual length. It is best to draw it longer. You then trim or extend the lines to their exact length using the FILLET command. This workalong will teach you how to do this.

Step 4

Using the LINE command and referring to the figures, draw the 6 lines to match the figure. (Figure Step 4A and 4B)

Figure Step 4B

Step 5

Using the LINE command, draw the vertical line. (Figure Step 5A and 5B)

Figure Step 5A
Figure Step 5B

AUTHOR’S COMMENTS: To draw this line, you must know its start point. Figure Step 5B shows how I solved the start point of the line. Since you don`t know the exact length of the line, guess at the length and try to draw it longer. I drew it 3.5 inches. Ensure you understand how I solved for the start point.

Step 6

Using the LINE command, draw the inclined line. First you have to solve the angle. Guess at the length and try to make it longer. After you know the angle and the length, snap to end point of the existing to start the line. (Figure Step 6A and 6B)

Figure Step 6A
Figure Step 6B

AUTHOR’S COMMENTS: Figure Step 6B shows the three steps I used to solve the angle of the line. Draw it longer than required since you don`t know its exact length. I drew it 2.0 inches long.

Step 7

Using the principles you just learned, use the LINE command to draw the two lines on the left side of the object. (Figure Step 7)

Figure Step 7

Step 8

Enter the FILLET command, as shown below, and select the two vertical lines to insert the fillet (tangent arc). (Figure Step 8A, 8B, and 8C)

Command: FILLET

Current settings: Mode = NOTRIM, Radius = 0.5000

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: T

Enter Trim mode option [Trim/No trim] <No trim>: T

Select first object or [Undo/Polyline/Radius/Trim/Multiple]:

Command: (This commands simply sets the FILLET command to trim objects when filleted. You only have to do this the first time you use the FILLET command or if you re-set it to NOTRIM.)

Command: FILLET

Current settings: Mode = TRIM, Radius = 0.0000

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: (Pick left vertical line)

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: (Pick right vertical line)

Select second object or shift-select to apply corner:

Command:

Figure Step 8A                                               Figure Step 8B
Figure Step 8C

AUTHOR’S COMMENTS: When the lines selected in the FILLET command are parallel, AutoCAD will automatically calculate the radius of the arc for you, regardless of the current radius setting. Note how the radius is set to zero in this example.

Step 9

Enter the FILLET command, as shown below, to insert a 0.5 radius fillet between the two lines. (Figure Step 9A. 9B, and 9C)

Command: FILLET

Current settings: Mode = TRIM, Radius = 0.0000

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: R

Specify fillet radius <0.0000>: 0.5 (Set the radius for the fillet.)

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: (Pick right vertical line)

Select second object or shift-select to apply corner: (Pick the horizontal line)

Command:

Figure Step 9A                                          Figure Step 9B                                       Figure Step 9C
AUTHOR’S COMMENTS: Since this fillet is inserted between lines that are not parallel, you must set the radius of the fillet. In this case, 0.5.

Step 10

Using what you learned in Step 9, insert the 0.5 radius fillet on the other side to match the figure. (Figure Step 10)

Figure Step 10

Step 11

Using what you learned in Step 9 and 10, insert the two 0.75 radius fillets on top left and right corners. (Figure Step 11)

Figure Step 11
AUTHOR’S COMMENTS: Ensure that you set the radius in the FILLET command to 0.75 before you select the lines to fillet.

Step 12

Insert the four 1.0 radius fillets to match the figure. (Figure Step 12)

Figure Step 12

Step 13

Enter the CIRCLE command and draw 1.0 diameter circle by snapping to the center of the arc to locate the its center. The completed drawing should match the figure. (Figure Step 13A and 13B)

Figure Step 13A
Figure Step 13B

AUTHOR’S COMMENTS: The circle and arc share the same center point. Ensure that AutoSnap is set to locate centers and Osnap is enabled. Use the CIRCLE command and snap to the center of the arc to locate the center of the circle.

Step 14

Save and close the drawing.

Figure 12-3
Object Snap Mode – Tangent

WORKALONG: Drawing Tangent Lines

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 12-2.

Step 3

Create the layers: Object and Construction. Set Layer: Construction as the current layer.

Step 4

Referring to the figures, draw the 2 radius circle with its center at 10,10. (Figure Step 4A and 4B)

Figure Step 4A
Figure Step 4B

Step 5

Using polar coordinates, enter the LINE command, two times, to draw two construction lines. Start each line starting at the center of the circle and ending at the center of the other two circles. (Figure Step 5)

Figure Step 5

Step 6

Draw circles locating their centers at the endpoints of the lines you drew in Step 5. (Figure Step 6)

Figure Step 6

Step 7

Enter the LINE command, as shown below, to draw a line tangent to the two circles. Enter the TAN object snap mode manually by typing it in on the keyboard. (Figure Step 7)

Command: LINE

Specify first point: TAN to P1

Specify next point or [Undo]: TAN to P2 Specify next point or [Undo]:

Command:

Figure Step 7

AUTHOR’S COMMENTS: Notice how you have to enter TAN for both ends of the line. It is a very common error to forget to enter it at the second end. Do not use AutoSnap, enter them manually by typing TAN on the keyboard and then press Enter. Note the AutoSnap marker when AutoCAD is finding the tangent location on the circle.

Step 8

Using what you learned in Step 7, enter the LINE command and draw a line tangent to the two circles as shown in the figure. (Figure Step 8)

Figure Step 8

Command: LINE

Specify first point: TAN to P3

Specify next point or [Undo]: TAN to P4

Specify next point or [Undo]:

Command:

AUTHOR’S COMMENTS: Note the AutoSnap Marker icon that displays when you use the TAN object snap mode.

Step 9

Using what you just learned, insert the two tangent lines as shown in the figure. (Figure Step 9)

Figure Step 9

Step 10

Using the FILLET command, insert a 3.0 radius fillet as shown in the figures. (Figure Step 10A , 10B, and 10C)

Figure Step 10A
Figure Step 10B
Figure Step 10C

Step 11

Change the layer of the objects from layer: Construction to layer: Object to match the figure. (Figure Step 11)

Figure Step 11

Step 12

Freeze layer: Construction. (Figure Step 12)

Figure Step 12

Step 13

Insert a 2.0 radius fillet to complete the drawing. (Figure Step 13)

Figure Step 13

Step 14

Save and close the drawing.

WORKALONG: Drawing Construction Techniques

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 12-3.

Step 3

Create layers: Object and Construction. Set layer: Construction as the current layer.

Step 4

Referring to the figures, enter the LINE command and draw the lines shown in the figures in two steps. (Figure 4A, 4B, and 4C)

Figure Step 4A
Figure Step 4B                                                      Figure Step 4C

AUTHOR’S COMMENTS: Draw the vertical line on the left side any length over 4 inches. The length is not important at this time.

Step 5

Enter the LINE command, as shown below, to draw two lines. (Figure Step 5)

Command: L

Specify first point:<Osnap on> (end) P1

Specify next point or [Undo]: @2<150

(Since you don’t know the length of the line, draw a line of any length at the correct angle.)

Specify next point or [Undo]:

Command: L

Specify first point: (end) P2

Specify next point or [Undo]: @3<210

(Draw any length line at the correct angle.)

Specify next point or [Undo]:

Command:

Figure Step 5

Step 6

Enter the FILLET as shown below. Set the radius to 0 to create perfect corners. (Figure Step 6A and 6B)

Command: FILLET

Current settings: Mode = TRIM, Radius = 0.3500

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: R

Specify fillet radius <0.3500>: 0

(Set the radius to zero.)

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: P3

Select second object or shift-select to apply corner: P4

Command: F

(F is the shortcut for the command FILLET.)

Current settings: Mode = TRIM, Radius = 0.0000

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: P5

Select second object or shift-select to apply corner: P6

Command:

Figure Step 6A                                                                                  Figure Step 6B
AUTHOR’S COMMENTS: By setting the fillet radius to zero, the FILLET command will trim the lines to create perfect corners.

Step 7

Change the layer of the necessary lines to reside on layer: Object. Freeze layer: Construction. (Figure Step 7)

Figure Step 7

Step 8

Save and close the drawing.

USER TIP: To insert an arc at the end of two parallel lines, use the FILLET command.Regardless of what radius is currently set in the FILLET command, AutoCAD will draw a tangent arc using the one-half distance between the lines as the radius. The lines do not have to be the same length.

Command: FILLET

Current settings: Mode = TRIM, Radius = 0.0

(Notice how the radius is set to zero. It can be any size.)

Select first object or [Polyline/Radius/Trim]: P1

(The first line you pick will retain it’s original length and the second one will be trimmed or extended.)

Select second object: P2

Command

Before

USER TIP: By setting the radius of the FILLET command to zero, the FILLET command will square the lines to make a perfect corner. The lines can be too short or too long or a combination of the two as shown in the figure on the right.

Before After

Key Principles

Key Principles in Module 12

  1. Point of tangency is the theoretical point where a line joins an arc, two arcs join each other, or two circles join each other making a smooth transition.
  2. A fillet is a tangent arc. To construct a fillet, use the FILLET command. The rule of thumb to follow is ‘ If the arc you are drawing is tangent to both objects it is connecting to, use the FILLET command. If the arc is tangent to one or neither of the objects, use the ARC command ‘.
  3. Use the LINE command and the TAN object snap mode to draw lines tangent to two circles or arcs. Make sure that you apply it to both ends of the line.
  4. By setting the radius of the FILLET command to zero, the FILLET command will square two lines to make a perfect corner.

Lab Exercise 12-1

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 12-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object Lines, circle and arcs Red

Step 1

Draw the object shown in the figures using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A

AUTHOR’S COMMENTS: Do not delete the construction lines.

 

Figure Step 1B
Completed Drawing

Step 2

Set the insertion units and check your drawing with the key.

Step 3

Turn layer: Key off and freeze layer: Construction.

Step 4

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hint. If you get stuck and cannot complete it on your own, use the following hint to help you.

Hint 1

The dashed line shown in the dimensioned drawing indicates that the lines should be constructed tangent to the small circle from the circles on either end of the object. After the lines are inserted tangent to both circles, you can then insert the fillet. (Figure Hint 1)

 

Figure Hint 1

Lab Exercise 12-2

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 12-2 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object Lines, circles and arcs Red

Step 1

Draw the object shown in the dimensioned drawing using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A
AUTHOR’S COMMENTS: Do not delete the construction lines
Figure Step 1B
Completed Drawing

Step 2

Set the insertion units and check your drawing with the key.

Step 3

Turn layer: Key off and freeze layer: Construction.

Step 4

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Draw a construction line from the midpoint of the line across the bottom of the slot 95 units in the positive Y direction. Draw a circle with its center at the end of the line. (Figure Hint 1)

Figure Hint 1

Hint 2

Since you don’t know the exact length of the lines shown in the figure, draw them any length but in the correct direction. When you insert the fillets, the line will automatically be trimmed. (Figure Hint 2)

Figure Hint 2

 

13

Module 13: Object Properties

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe object properties, linetype, and linetype scale.
  2. Describe how to assign and edit linetypes ByLayer and set their linetype scale.
  3. Apply the PROPERTIES and LTSCALE commands to display and edit properties of drawing objects and set the linetype scale of objects.
  4. Describe how to select objects using a pick, a window, and a crossing window.

Object Properties

Figure 13-1
Properties of a Line

AutoCAD stores all existing objects and their properties in a database file called the drawing file. The name of the file is the drawing name that you assigned to the drawing and AutoCAD automatically assigns the extension .dwg. The drawing file stores all existing drawing objects along with the properties of each object in a database. The drawing objects that have been taught up to now are lines, circles, and arcs. Figure 13-1 displays the properties of a line.

When an existing drawing is opened, AutoCAD reads the drawing file and uses it to construct the objects from the database and displays the objects in the Graphic window. The REGEN command does the same thing for the current drawing.

The PROPERTIES command opens the Properties window. Properties of existing drawing objects can be modified using commands or they can be edited in the Properties window. It is faster and easier to edit the properties in the Properties window but not all of the properties can be edited using it. AutoCAD grays the boxes of the properties that cannot be changed in the window. See Figure 13-1.

Without entering a command, one or more objects in the current drawing can be selected using the pick box. The selected object(s) will highlight and the data will appear in the Properties window. If more then one object is selected, only the properties which are common to all of the selected objects will display. To unselect objects, press the Esc key.

Figure 13-2 shows the Properties window where only one line was selected by the user. This can be seen in the box located in the top left corner of the window. This box will display what object(s) is currently selected and its properties are displayed below in the window.

Figure 13-2
The Properties Dialogue Box

Linetypes

A linetype is a repeating pattern of dots, dashes, text, objects, or blank spaces displayed on a drawing object. Up to this point in the book, the default linetype Continuous has been assigned to all objects. See Figure 13-3. A continuous linetype displays solid. In this module, linetypes will be assigned ByLayer. The template files that you are using are only loaded with the Continuous linetype. Before a linetype can be assigned to a layer, it must be loaded into the current drawing’s database. All loaded linetypes will remain in the drawing file for future use. If required, they can be purged out of the drawing file. Purging is taught in Module 34.

Figure 13-3
Continuous Linetype

AutoCAD Command: PROPERTIES

The PROPERTIES command opens the Properties window.

Shortcut: CTRL+1

Standard Toolbar
Tools Pull-down
Properties Window
View Ribbon

AutoCAD Command: LTSCALE

The LTSCALE system variable is used to set the global linetype scale for the drawing.

Shortcut: LTS

MUST KNOW: The AutoCAD drawing file contains all of the data that relates to the drawing in a database. When an existing drawing is opened, AutoCAD uses the drawing file to construct the drawing objects in the Graphic window. When the current drawing is saved, AutoCAD updates the drawing file. AutoCAD adds the extension .dwg to the user assigned drawing name. For example, if you name the drawing House Plan, AutoCAD will name the file House Plan.dwg, when the file is saved.

MUST KNOW: Before AutoCAD displays the linetype on a drawing object, it multiplies the scale factor set in LTSCALE times the linetype scale property that is assigned to the drawing object.

For example, if the LTSCALE is set to 5 and the drawing object’s linetype scale property is set to 2, AutoCAD will display the object with the linetype scale of 10. In other words, it will display the linetype 10 times larger then its normal display.

It is best to set the LTSCALE to 1 and set the drawing object’s linetype scale property to the setting to display the desired linetype and that makes it easier for you to set the linetype scale.

For example, if the LTSCALE is set to 1 and the objects linetype scale property is set to 10, AutoCAD will display the drawing object with the linetype scale of 10 or 10 times its normal display.

USER TIP: The Quick Properties window will open automatically when a drawing object is double clicked with the left mouse button. This saves you one step when editing or inquiring about the object’s properties.

WORKALONG: Working with Linetypes and Linetype Scales

Step 1

Start a new drawing using template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 13-1.

Step 3

Open the Layer Properties Manager window and create the layers: Hidden, Object 1, and Object 2. (Figure Step 3)

Figure Step 3

Step 4

Click layer: Hidden to select it. Select Continuous. This will open the Select Linetype dialogue box. (Figure Step 4)

Figure Step 4

AUTHOR’S COMMENTS: As you can see, the only linetype currently loaded in the drawing is Continuous.

Step 5

Click the Load button to open the Load or Reload Linetypes dialogue box. The name in the File box will be one of the following: (Figure Step 5).

ACAD.LIN – English

ACADISO.LIN – Metric

Figure Step 5
Figure Step 5

AUTHOR’S COMMENTS: There is an english and a metric linetype file. The template that was used to start the drawing dictates the file that the dialogue box will display.

USER TIP: It easier to load all the linetypes into your current drawing rather then selecting them individually. To do this, click any linetype to select it and then press Ctrl+A. This will select all linetypes.

Step 6

Scroll down until you find the linetype: DASHDOT. Select it as shown in the figure. (Figure Step 6)

Figure Step 6

Step 7

While holding down the Ctrl key, scroll down until you find the linetypes: HIDDEN and PHANTOM2. Select them. They will highlight as shown in the figure. Click OK to close the dialogue box. (Figure Step 7).

Figure Step 7

AUTHOR’S COMMENTS: You must hold the Ctrl key down to select more then one linetype at the same time.

Step 8

The linetypes you selected in Step 7 will display in the Select Linetype dialogue box. Click OK to close the dialogue box. (Figure Step 8)

Figure Step 8

AUTHOR’S COMMENTS: There are now 4 linetypes loaded in this drawing.

Step 9

In the Layer Properties Manager window, click layer: Hidden and click the linetype: Continuous. In the Select Linetype dialogue box, select the linetype: HIDDEN and then click OK. (Figure Step 9)

Figure Step 9

Step 10

Using what you just learned, change the linetype for layer: Object 1 to linetype: DASHDOT and layer: Object 2 to the linetype: PHANTOM2. (Figure Step 10)

Figure Step 10

Step 11

Change the colors of the layer: Hidden to blue and layer: Object 1 to red to match the figure. (Figure Step 11)

Figure Step 11

Step 12

Draw three 2-inch diameter circles on layer 0 locating their centers at the coordinates shown in the figure. (Figure Step 12)

Figure Step 12

Step 13

Open the Properties window and select the top left circle. While it is selected, change it to layer: Hidden as shown in the figure. (Figure Step 13)

Figure Step 13

Step 14

Select the center circle. In the Properties window, change it to layer Object 1. (Figure Step 14)

Figure Step 14

Step 15

Select the bottom right circle. In the Properties window, change it to layer: Object 2. Your drawing should now appear as shown in figure. (Figure Step 15A and 15B)

Figure Step 15A
Figure Step 15B

Step 16

Select the top left circle. In the Properties window, change the Linetype scale property to 0.750. (Figure Step 16)

Figure Step 16

Step 17

Select the middle circle. In the Properties window, change the Linetype scale property to 0.500. (Figure Step 17)

Figure Step 17
USER TIP: Understanding and using object properties to edit and inquire about drawing objects is very important to your drawing speed and production. Whenever possible, use the Properties window to edit objects rather than using AutoCAD commands to do the same thing.

Step 18

Select the bottom circle. In the Properties window, change the Linetype scale property to 1.500. (Figure Step 18)

Figure Step 18

AUTHOR’S COMMENTS: You can see that by changing the Linetype scale property of the object, It changes it’s appearance.

Step 19

Enter the LTSCALE system variable as shown below and ensure that it is set to 1.

Command: LTSCALE

Enter new linetype scale factor <1.0000>:

Command:

AUTHOR’S COMMENTS: If it is not set to 1, enter 1 to the prompt.
AUTHOR’S COMMENTS: If possible, always leave the LTSCALE system variable set to 1.

Step 20

Your completed drawing should appear as shown in the figure. (Figure Step 20)

Figure Step 20

Step 21

Save and close the drawing.

Selecting Objects

After entering a command that requires you to select one or more objects, AutoCAD will display the Select object: prompt. To draw faster, it is important for you to be able to select objects in the most time efficient method since many commands require object selection. There are many methods of selecting objects and they will be taught in future module. In this module, the pick, window, and crossing window methods are taught. See Figure 13-4.

Figure 13-4 Selecting Objects Using Pick, Window, and Cross Window

WORKALONG: Selecting Objects

Step 1

Open the drawing: AutoCAD 2D Lab 12-2. (Figure Step 1)

Figure Step 1

Step 2

Using the SAVEAS command, save and name the drawing:

AutoCAD 2D Workalong 13-2.

Step 3

Enter the ERASE command as shown below. When you are prompted to Select objects, select the circle with the pickbox and press the Enter key. (Figure Step 3A and 3B)

Command: ERASE

Select objects:

Command:

Figure Step 3A
Figure Step 3B
AUTHOR’S COMMENTS: It is important to understand that when you select objects by selecting them with the pickbox, only one object is selected per pick. If there are more then one circle with the same diameter at the same location, there would still be a circle remaining after you execute the ERASE command.

Step 4

Enter the ERASE command. When prompted to Select objects, select two locations to form a window. You must select the locations on opposite corners from left to right. A window is colored blue and has a solid line around it. Press Enter to execute the command. (Figure Step 4A and 4B)

AUTHOR’S COMMENTS: A window must be selected from left to right and will select only the objects that are located totally inside the window. In this case, the arc. The lines that are not totally inside the window will not be selected.
Figure Step 4A
Figure Step 4B
AUTHOR’S COMMENTS: It is important to understand that when you select objects using a window, all of the objects that are totally inside the window are selected. If there is more then one arc with the same radius at the same location, all of them would also be erased.

Step 5

Enter the U command to undo that last command. The arc you just erased will redisplay on the drawing. (Figure Step 5)

Figure Step 5
MUST KNOW: It is very important to understand how objects are selected. If you use the pick method to select the objects, AutoCAD will select only one object, even though two or more objects are located exactly at the same location. If you select the objects using either the window or cross window method, AutoCAD will select all of the objects, even though two or more objects are located exactly at the same location.

Step 6

Enter the ERASE command. When you are prompted with the Select objects prompt, select two locations moving from right to left. The two locations must be the opposite corners of the crossing window. Press Enter to execute the command. (Figure Step 6A and 6B)

Figure Step 6A
Figure Step 6B

AUTHOR’S COMMENTS: A crossing window must be selected from right to left and will select all of the objects that the window crosses and all of the objects that are located totally inside the crossing window. In this case, the arc and the two lines.

Step 7

Enter the U command as many times as required to display the drawing as shown in the figure. (Figure Step 7)

Figure Step 7
MUST KNOW: It is very important to understand how objects are selected. If you use the pick method to select the objects, AutoCAD will select only one object, even though two or more objects are located exactly at the same location. If you select the objects using either the window or cross window method, AutoCAD will select all of the objects, even though two or more objects are located exactly at the same location.

Step 8

Without entering a command and using what you learned earlier, place a window as shown in the figure. All of the objects that are totally inside the window will highlight and display grips. Press the Delete key to delete the objects. (Figure Step 8A, 8B, and 8C)

Figure Step 8A                                                             Figure Step 8B                                                  Figure Step 8C

Step 9

Enter the U command to undo that last command. The arcs and line you just erased will redisplay on the drawing.

Step 10

Without entering a command and using what you learned earlier, place a crossing window as shown in the figure. All of the objects that cross the window and all of the objects that are totally inside the window will be selected and display grips. Press the Delete key to delete the objects. (Figure Step 10A, 10B, and 10C)

Figure Step 10A
Figure Step 10B
Figure Step 10C

Step 11

Enter the U command to undo that last command.

Step 12

Save and close the drawing.

Geometry Lesson: A Compound Fillet

A compound fillet is two or more tangent arcs used to create a continuous curve. Study Figure 13-5. Note the small dashed line. It is a drafting standard to indicate that the 3 R (Radius) arc is tangent to the line and small circle as shown in Step 1. The 1 R tangent arc is then inserted tangent to 3 R arc and the large circle as shown in Step 2. Since they are tangent arcs, you would use the FILLET command, two times, to draw them.

Figure 13-5
A Compound Fillet
Step 1                                                                                                        Step 2
USER TIP: Always leave the setting for LTSCALE to 1 and set the drawing object’s linetype scale property to the setting to display the desired linetype.

Key Principles

Key Principles in Module 13

  1. AutoCAD stores all existing drawing objects and their properties in a database file called the drawing file. The name of the file is the drawing name with the extension .dwg.
  2. A linetype is a repeating pattern of dots, dashes, text, objects, or blank spaces displayed on the object. It is an appearance only and does not change the object in any way.
  3. The individual linetype scale property multiplies the scale factor it is set to times the existing scale factor of the global linetype scale (LTSCALE). It is best to set LTSCALE to 1 at all times.
  4. If you use the pick method to select the objects, AutoCAD will select only one object, even though two objects are exactly located at the same location. If the same objects are selected using either the window or cross window method, AutoCAD will select all objects even if they are at the exact same location.

Lab Exercise 13-1

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 13-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A
AUTHOR’S COMMENTS: Do not delete the construction lines.
Figure Step 1B
Completed Drawing

Step 2

Set the insertion units and check your drawing with the key.

Step 3

Turn layer: Key off and freeze layer: Construction.

Step 4

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

See the following step:

Step 1

Draw the lines, circles and arcs as shown in the figure. (Figure Hint Step 1)

Figure Hint Step 1

Step 2

Draw two horizontal lines, of any length, starting at the ends of the arc on the left. (Figure Hint Step 2)

Figure Hint Step 2

Step 3

Insert a 1 radius fillet between the horizontal line and the circle. (Figure Hint Step 3)

Figure Hint Step 3

Step 4

Insert a 2 radius fillet between the two circles on the top right and another one between the horizontal line and circle on the bottom left. (Figure Hint Step 4)

Figure Hint Step 4

Step 5

Insert a 3 radius fillet between the two circles on the bottom right. (Figure Hint Step 5)

Figure Hint Step 5

Step 6

Using the Properties window, change the layer of the arcs to layer: Object. (Figure Hint Step 6)

Figure Hint Step 6

Step 7

Freeze layer: Construction. (Figure Hint Step 7)

Figure Hint Step 7

Step 8

Using the FILLET command, insert three fillets, using the applicable radius, between the arcs. (Figure Hint Step 8)

Figure Hint Step 8

Lab Exercise 13-2

Time allowed: 20 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 13-2 N/A N/A
Layering Scheme
Layer Name Objects on Layer Color Line Type
Outline Outline of object Red Phantom 2
Circle Full circles Green Border 2
Slot The slot Blue Dashed 2

Step 1

Open the drawing: AutoCAD 2D Lab 13-1.

Step 2

Using the SAVEAS command, save the drawing with the name: AutoCAD 2D Lab 13-2.

Step 3

Open the Layer Property Manager window and change the linetypes of the layers to match the layering scheme shown above.

Step 4

Using the Properties window, change the layers of the objects to match the layering scheme shown above.

Step 5

Change the linetype scale of each object to match the figure. (Figure Step 5)

Figure Step 5
AUTHOR’S COMMENTS: You will have to guess at the linetype scale and then adjust it. Do your best to match the figure, by eye, as closely as you can.

Lab Exercise 13-3

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 13-3 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A
AUTHOR’S COMMENTS: Do not delete the construction lines.

Step 2

Set the insertion units and check your drawing with the key.

Step 3

Turn layer: Key off and freeze layer: Construction.

Step 4

Save and close the drawing.

Figure Step 1B
Completed Drawing
AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

See the following steps:

Step 1

Draw the lines and circles as shown in the figure. (Figure Hint Step 1)

Figure Hint Step 1

Step 2

Enter the FILLET command and set the radius to 400. For the first object, select the large circle on the left. For the second object, select the middle circle on the right. (Figure Hint Step 2A, 2B, and 2C)

Figure Hint Step 2A
Figure Hint Step 2B
Figure Hint Step 2C

Step 3

Using what you learned in Step 2, insert the compound bottom fillet. You will have to change the radius to 500. (Figure Hint Step 3)

Figure Hint Step 3

Step 4

Enter the FILLET command and set the radius to 150. For the first object, select the fillet inserted in Step 2. For the second object, select the large circle on the right. Figure Hint Step 4A, 4B, and 4C)

Figure Hint Step 4A
Figure Hint Step 4B
Figure Hint Step 4C

Step 5

Using what you learned in Step 4, insert the fillet on the bottom. (Figure Hint Step 5)

Figure Hint Step 5

Step 6

Insert a 25 radius fillet between the circles on the left. (Figure Hint Step 6)

Figure Hint Step 6

Step 7

Change the layer of the fillets to layer: Object. (Figure Hint Step 7)

Figure Hint Step 7

Step 8

Freeze layer: Construction. (Figure Hint Step 8)

Figure Hint Step 8

Step 9

Insert two 15 radius fillets between the arcs on the left. (Figure Hint Step 9)

Figure Hint Step 9

Lab Exercise 13-4

Time allowed: 20 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 13-4 N/A N/A
Layering Scheme
Layer Name Objects on Layer Color Line Type
Circles All circles Blue Dashed
Arcs All arcs Magenta Phantom

Step 1

Open the drawing: AutoCAD 2D Lab 13-3.

Step 2

Using the SAVEAS command, save the drawing with the name: AutoCAD 2D Lab 13-4.

Step 3

Open the Layer Property Manager window and change the linetypes of the layers to match the layering scheme shown above.

Step 4

Using the Properties window, change the layers of the objects to match the layering scheme shown above.

Step 5

Change the linetype scale of each object to match the figure. (Figure Step 5)

Figure Step 5

AUTHOR’S COMMENTS: You will have to guess at the linetype scale and then adjust it. Do your best to match the figure, by eye, as closely as you can.

14

Module 14: Trimming and Extending

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe the geometry of regular polygons.
  2. Apply the TRIM and EXTEND commands to shorten and lengthen drawing objects at selected cutting edges.

Geometry Lesson: Regular Polygons

A polygon is defined as any plane figure bounded by straight lines. A regular polygon is a polygon that has equal angles, equal sides, and can be inscribed or circumscribed around a circle. AutoCAD has a command to automatically construct polygons and it will be taught in a future module. For now, it is important for you to be able to construct polygons using geometry.

The first nine regular polygons are shown in Figure 14-1.

Figure 14-1
Regular Polygons

Any regular polygon can be inscribed in or circumscribed around a circle as shown, using a hexagon, in Figure 14-2.

Figure 14-2
Inscribed and Circumscribed Regular Polygon

It is important to understand and know the geometry involved to construct a triangle, square, hexagon, and octagon as shown in Figure 14-3. Study each one and try to understand how they are constructed and the angles used to construct them.

Figure 14-3
Geometry of Four Regular Polygons

The following are the steps used to draw a hexagon in an AutoCAD drawing. See Figure 14-4.

Step 1

Draw 6 lines on layer Construction from the center to each corner, 60 degrees apart.

Step 2

Draw six lines snapping from the end of one line to the end of the next line.

Step 3

Turn layer Construction off.

Figure 14-4
Drawing a Hexagon

Trimming and Extending

Not every object can be drawn using exact coordinates or locations as has been taught to this point in the book. There are times where it is essential that objects be drawn to approximate lengths and sizes and then trimmed or extended to their exact size and location. This does not mean that you can guess at the size and location of the objects. Objects must still be drawn with 100 percent accuracy. The length can be approximated and then adjusted using the TRIM or EXTEND commands. These two commands are a big part of you becoming more productive.

In AutoCAD 2021 there have been changes to the Trim and extend commands and the default settings will not produce the expected results in the following tutorials. The default MODE setting, QUICK, will give access to the [cutting edges/Crossing/mode/Project/erase] options, which should be set as explained later in this tutorial. Then, as a last step, the mode should be set to standard. This will produce the expected behavior of TRIM and EXTEND. If you do not see the above options, set the MODE to Quick, make the setting changes and then restore the MODE setting to Standard.

USER TIPS: With both the TRIM and EXTEND commands, a very common beginner’s error is picking the wrong objects first. Always select the cutting edge object(s) first, press the Enter or Space next, and then select the objects to be trimmed or extended.

AutoCAD Command: TRIM

The TRIM command is used to shorten objects to meet the edges of other objects. It is not required for the object being trimmed to intersect with the object forming the cutting edge.

Shortcut: TR

Modify Toolbar
Modify Pull-down
Home Ribbon

AutoCAD Command: EXTEND

The EXTEND command is used to lengthen objects to meet the edges of other objects. It is not required for the object being extended to intersect with the object forming the cutting edge.

Shortcut: EX

Modify Toolbar
Modify Pull-down
Home Ribbon

WORKALONG: Using the TRIM and EXTEND Commands

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 14-1.

Step 3

Create the layers: Object and Construction. Set layer: Construction as the current layer.

Step 4

Using the figures as a reference, enter the LINE command, as shown on the below, to draw the construction lines shown in Figure Step 4B. (Figure Step 4A and 4B)

Figure Step 4A

Command: L

Specify first point: 2.5,4.5

Specify next point or [Undo]: @1,0

Specify next point or [Undo]: @2,0

Specify next point or [Close/Undo]: @1,0

Specify next point or [Close/Undo]: @0,4

Specify next point or [Close/Undo]: @0,1

Specify next point or [Close/Undo]: @-3,0

Specify next point or [Close/Undo]: @2<220

Specify next point or [Close/Undo]:

Command: L

Specify first point: (end) P1

Specify next point or [Undo]: @0,5

Command: L

Specify first point: (end) P2

Specify next point or [Undo]: @1<145

(The length of this line can be any length but the direction must be accurate. I purposely drew it shorter to demonstrate the EXTEND command.)

Command:

Figure Step 4B

AUTHOR’S COMMENTS: Notice how the object is drawn with a series of construction lines that go from point to point on the object rather than from corner to corner. This is done so that the endpoints of the lines can be used as snap point later in the construction.

Step 5

Enter the TRIM command as shown below. (Figure Step 5).

Command: TRIM

Current settings: Projection=UCS, Edge=None

Select cutting edges …

Select objects or <select all>:

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: E

Enter an implied edge extension mode [Extend/No extend] <No extend>: E

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]:

Command:

AUTHOR’S COMMENTS: The Edge option in the TRIM command should be set to Extend most of the time. Once it is set on your computer, it will stay that way until you change it.

Command: TRIM

Current settings: Projection=UCS, Edge=Extend

Select cutting edges …

Select objects or <select all>: P3 1 found

Select objects: P4 1 found, 2 total

(These lines are the cutting edges.)

Select objects:

(Press enter or space.)

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P5

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P6

(These are the lines to trim. Select the line close to the end to be trimmed.)

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]:

Command:

Figure Step 5

Step 6

Enter the EXTEND command, as shown below, to extend the line to top line in object. (Figure Step 6A and 6B)

Command: EXTEND

Current settings: Projection=UCS, Edge=Extend

Select boundary edges …

Select objects or <select all>: P7 1 found

(The cutting edge.)

Select objects:

(Press enter or space.)

Select object to extend or shift-select to trim or [Fence/Crossing/Project/Edge/Undo]: P8

(The line to extend. Select the line close to the end that is to be extended.)

Select object to extend or shift-select to trim or [Fence/Crossing/Project/Edge/Undo]:

Command:

Figure Step 6A
Figure Step 6B

Step 7

Draw three construction lines starting at the midpoint of the bottom line. (Figures Step 7)

Command: L

Specify first point: (mid) P9

Specify next point or [Undo]: @0,1

Specify next point or [Undo]: @0,1.5

Specify next point or [Close/Undo]: @0,1.5

Specify next point or [Close/Undo]:

Command:

Figures Step 7

AUTHOR’S COMMENTS: Notice how the three lines are drawn end to end even though they look like one line. This is done to establish the endpoints so that they can be snapped onto later to construct the object.

Step 8

Enter the LINE commands, as shown below, to insert the construction lines for the hexagon. Each line starts at the end of the construction line drawn in Step 7. (Figure Step 8)

Command: L

Specify first point: (end) P10

Specify next point or [Undo]: @.5<30

Specify next point or [Close/Undo]:

Command: L

Specify first point: (end) P10

Specify next point or [Undo]: @.5<90

Specify next point or [Close/Undo]:

Command: L

Specify first point: (end) P10

Specify next point or [Undo]: @.5<150

Specify next point or [Close/Undo]:

Command: L

Specify first point: (end) P10

Specify next point or [Close/Undo]: @.5<210

Specify next point or [Close/Undo]:

Command: L

Specify first point: (end) P10

Specify next point or [Undo]: @.5<270

Specify next point or [Close/Undo]:

Command: LINE Specify first point:

Command: L

Specify first point: (end) P10

Specify next point or [Undo]: @.5<330

Specify next point or [Close/Undo]:

Command:

Figure Step 8

Step 9

Enter the LINE command, as shown below, to construct the lines for the hexagon. Ensure that you have Autosnap enabled and you snap to the endpoints of the lines. (Figure Step 9)

Command: L

Specify first point: (end) P11

Specify next point or [Undo]: (end) P12

Specify next point or [Undo]: (end) P13

Specify next point or [Close/Undo]: (end) P14

Specify next point or [Close/Undo]: (end) P15

Specify next point or [Close/Undo]: (end) P16

Specify next point or [Close/Undo]: (end) P11

Specify next point or [Close/Undo]:

Command:

Figure Step 9

Step 10

Enter the LINE and CIRCLE commands, as shown below, to draw the slot. (Figure Step 10A and 10B)

Command: L

Specify first point: (end) P17

Specify next point or [Undo]: @1,0

Specify next point or [Undo]:

Command: L

Specify first point: (end) P17

Specify next point or [Undo]: @-1,0

Specify next point or [Undo]:

Command: C

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: (end) P18

Specify radius of circle or [Diameter]: D

Specify diameter of circle: .5

Command: C

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: (end) P19

Specify radius of circle or [Diameter] <0.2500>:

Command: L

Specify first point: (quad) P20

Specify next point or [Undo]: (quad) P21

Specify next point or [Undo]: Command: L

Specify first point: (quad) P22

Specify next point or [Undo]: (quad) P23

Specify next point or [Undo]:

Command:

Figure Step 10A
Figure Step 10B
AUTHOR’S COMMENTS: Ensure that you snap to the object snap mode shown before each pick in the command.

Step 11

Enter the commands, as shown below, to draw the construction objects for the bottom arc. (Figure Step 11A and 11B)

Command: C

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: (end) P24

Specify radius of circle or [Diameter]: D

Specify diameter of circle: 1

Command: L

Specify first point: (cen) P25

Specify next point or [Undo]: (end) P26

Specify next point or [Undo]:

Command: L

Specify first point: (cen) P25

Specify next point or [Undo]: (end) P27

Specify next point or [Undo]:

Command:

Figure Step 11A
Figure Step 11B
AUTHOR’S COMMENTS: I find it easier to draw circles rather than arcs. Then I trim them to construct the required arc.

Step 12

Enter the TRIM command, as shown below, to create the slot. (Figure Step 12A and 12B)

Command: TRIM

Current settings: Projection=UCS, Edge=Extend

Select cutting edges …

Select objects or <select all>: P28 1 found

Select objects: P29 1 found, 2 total

Select objects:

(Press enter or space.)

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P30

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P31

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]:

Command:

Figure Step 12A
Figure Step 12B

Step 13

Enter the TRIM command, as shown below, to create the bottom arc. (Figure Step 13A and 13B)

Command: TRIM

Current settings: Projection=UCS, Edge=Extend

Select cutting edges …

Select objects or <select all>: P32 1 found

Select objects: P33 1 found, 2 total

Select objects: P34 1 found, 3 total

Select objects:

(Press enter or space)

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P35

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]:P36

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P37

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]:

Command:

Figure Step 13A
Figure Step 13B

Step 14

Enter the TRIM command, as shown below, to trim the line on the top right. (Figure Step 14A and 14B)

Command: TRIM

Current settings: Projection=UCS, Edge=Extend

Select cutting edges …

Select objects or <select all>: P38 1 found

Select objects:

(Press enter or space)

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P39

Select object to trim or shift-select to extend or

[Fence/Crossing/Project/Edge/eRase/Undo]:

Command:

Figure Step 14A
Figure Step 14B

Step 15

Change the layer of the objects that you want to reside on layer: Object. (Figure Step 15)

Figure Step 15

Step 16

Freeze layer: Construction. Your completed drawing should appear as shown in the figure. (Figure Step 16)

Figure Step 16

Step 17

Save and close the drawing.

MUST KNOW: The Edge option in the TRIM and EXTEND commands should always be set to Extend as shown below. Step 5 will show you how to set it. See also the 2nd paragraph in the notes on Trim an Extend.

Command: TRIM

Current settings: Projection=UCS, Edge=Extend

USER TIP: The TRIM and EXTEND commands areinterchangeable. If you enter either command, you can change over to the other command by holding down the Shift key. i.e.
Command: TRIM (See Figure Step 1.)

Current settings: Projection=UCS, Edge=None
Select cutting edges …Select objects or <select all>: P1 1 found
Select objects: P2 1 found, 2 total
Select objects: P3 1 found, 3 total
Select objects: P4 1 found, 4 total

Select objects:

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: E

(Enter the Edge option.)

Enter an implied edge extension mode [Extend/No extend] <No extend>: E

(Set it to Extend. This allows you to trim or extend when the objects do not physically touch.)

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P5

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P6

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P7

(Press and hold down the Shift key to change to the EXTEND command.)

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P8

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P9

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]: P10

Select object to trim or shift-select to extend or [Fence/Crossing/Project/Edge/eRase/Undo]:

Command:

Figure Step 2                                                                                                      Completed Drawing

Key Principles

Key Principles in Module 14

  1. To improve your drawing productivity, draw the location and direction of objects with 100 percent accuracy but at an arbitrary length. Adjust the length with the TRIM or EXTEND commands.
  2. With both the TRIM and EXTEND commands, select the cutting edge objects first, press the Enter or Space key, and then select the object(s) to trim or extend.
  3. The TRIM and EXTEND commands are interchangeable by holding down the Shift key to change from one command to the other.

Lab Exercise 14-1

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 14-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object 1 All objects Red

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A
AUTHOR’S COMMENTS: Do not delete the construction lines.
Figure Step 1B

Step 2

Set the insertion units and check your drawing with the key.

Step 3

Turn layer: Key off and freeze layer: Construction.

Step 4

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Draw the lines in the correct location and direction but to any length and then trim or extend them. (Figure Hint 1)

Figure Hint 1

Hint 2

The lines in Figure Hint 2A must be drawn tangent to tangent (see Module 12) while the lines in Figure Hint 2B can be draw either tangent to tangent or quad to quad. (Figure Hint 2A and 2B)

Figure Hint 2A                                                                                    Figure Hint 2

Hint 3

The figure shows the construction lines. (Figure Hint 3)

Figure Hint 3

Lab Exercise 14-2

Time allowed: 30 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 14-2 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Linetype Color
Construction Construction objects Continuous 253
Circle 1 Outside circle Center2 Red
Circle 2 Inside circles Continuous Red
Slots Slots Dashdot2 Blue

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A

AUTHOR’S COMMENTS: Do not delete the construction lines.

Figure Step 1B
Completed Drawing

Step 2

Set the insertion units and check your drawing with the key.

Step 3

Turn layer: Key off and freeze layer: Construction.

Step 4

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Step 1

Draw only four construction lines at the correct angle as shown in the figure. Extend them to other side of the large circle. That will save you from drawing all 8 lines. (Figure Step 1A and 1B)

Figure Step 1A
Figure Step 1B

Step 2

Draw 8 circles locating their centers at the intersection of the lines and circle. (Figure Step 2)

Figure Step 2

Step 3

Draw 2 large circles by showing AutoCAD the radius by snapping to the intersection of the small circle and line. (Figure Step 3)

Figure Step 3

Step 4

Trim the large circles. (Figure Step 4)

Figure Step 4

Step 5

Trim the slots. (Figure Step 5)

Figure Step 5

Lab Exercise 14-3

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 14-3 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Concrete Block All objects Blue

Step 1

Draw the top view of the concrete block shown in the figure using the layering scheme. (Figure Step 1A, 1B, and 1C)

Figure Step 1A
Figure Step 1B Concrete Block
Figure Step 1C Completed Drawing

Step 2

Set the insertion units and check your drawing with the key. Turn layer: Key off and freeze layer: Construction.

Step 3

Save and close the drawing.

15

Module 15: Offsetting Objects

Learning Outcomes

When you have completed this module, you will be able to:

  1. Apply the OFFSET command to insert objects parallel to existing objects.
  2. Apply the ID command to establish temporary reference locations.
  3. Describe and apply the object snap mode Perpendicular.

Offsetting

The OFFSET command allows you to create a drawing object parallel to an existing drawing object at a specified distance from the original object. OFFSET is a powerful command and if used when applicable, will change the way you construct objects and improve your drawing productivity. The drawing objects lines, circles, and arcs can be offset plus many others that you will be learning later in the book.

AutoCAD Command: OFFSET

The OFFSET command is used to create a drawing object parallel to an existing drawing object at a specified distance from the original object.

Shortcut: O

Modify Toolbar
Modify Pull-down
Home Ribbon

AutoCAD Command: ID

The ID command is used to return the coordinate location for a point in Model or Paper space.

Shortcut: none

Inquiry Toolbar
Tools Pull-down
Home Ribbon
Figure 15-1
Object Snap Mode – Perpendicular
MUST KNOW: Using the ID command to set a reference point or the lastpoint is a useful drawing tool. Once you pick an ID point, ignore the actual coordinates. On the next command, use an @ to locate a coordinate location from the ID point.

WORKALONG: Offsetting Objects

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 15-1. (Figure Step 2)

Figure Step 2

Step 3

Create the layers: Object and Construction. Set layer: Construction as the current layer.

MUST KNOW: When a drawing object is offset, the newly constructed offset drawing object will reside on the same layer as the original object, regardless of the current layer. If you want the newly created object to be on a different layer than the original object, you will have to change it’s properties after it is offset.

Step 4

Enter the LINE command, as shown below, to create the outline of the object. (Figure Step 4)

Command: L

Specify first point: 4,4

Specify next point or [Undo]: @-2.5,0

Specify next point or [Undo]: @0,5.5

Specify next point or [Close/Undo]: @4.5,0

Specify next point or [Close/Undo]: @0,-2.5

Specify next point or [Close/Undo]: @-2,0

Specify next point or [Close/Undo]: C

Command:

Figure Step 4

Step 5

Enter the commands, as shown below, to draw the circles and fillets. (Figure Step 5A and 5B)

Command: C

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: (mid) P1

Specify radius of circle or [Diameter] <0.1000>: (end) P2

(When possible, it is always better to show AutoCAD a distance rather then entering it on the keyboard.)

Command: C

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: (mid) P1

Specify radius of circle or [Diameter] <0.7500>: D

Specify diameter of circle <1.5000>: 1

Command: F

Current settings: Mode = TRIM, Radius = 0.0000

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: R

Specify fillet radius <0.0000>: 0.75

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: P3

Select second object or shift-select to apply corner: P4

Command: F

Current settings: Mode = TRIM, Radius = 0.7500

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: R

Specify fillet radius <0.7500>: 0.5

Select first object or [Undo/Polyline/Radius/Trim/Multiple]: P5

Select second object or shift-select to apply corner: P6

Command:

Figure Step 5A
Figure Step 5B

Step 6

Use the TRIM command to trim the circle. (Figure Step 6)

Figure Step 6

Step 7

Enter the OFFSET commands, as shown below. (Figure Step 7)

Command: OFFSET

Current settings: Erase source=No Layer=Source OFFSETGAPTYPE=0

Specify offset distance or [Through/Erase/Layer] <Through>: 0.5

(Set the offset distance.)

Select object to offset or [Exit/Undo] <Exit>: P10

(Select the object to offset.)

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P11

(Select which side of the object to offset it on.)

Select object to offset or [Exit/Undo] <Exit>: P12

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P13

Select object to offset or [Exit/Undo] <Exit>:P14

Command: OFFSET

Current settings: Erase source=No Layer=Source OFFSETGAPTYPE=0

Specify offset distance or [Through/Erase/Layer] <0.5000>: 1.5

(Set the offset distance.)

Select object to offset or [Exit/Undo] <Exit>: P14

(Select the object to offset.)

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>:P15

(Select which side of the object to offset it on.)

Select object to offset or [Exit/Undo] <Exit>:

Command: OFFSET

Current settings: Erase source=No Layer=Source OFFSETGAPTYPE=0

Specify offset distance or [Through/Erase/Layer] <1.5000>: 2.75

Select object to offset or [Exit/Undo] <Exit>: P16

Specify point on side to offset or [Exit/Multiple/Undo]

<Exit>:P17

Select object to offset or [Exit/Undo] <Exit>:

Command:

Figure Step 7

Step 8

Using the FILLET command, insert a 0.5 radius fillet on all four corners. (Figure Step 8)

Figure Step 8

Step 9

Enter the OFFSET command, as shown below. (Figure Step 9)

Command: O

Current settings: Erase source=No Layer=Source

OFFSETGAPTYPE=0

Specify offset distance or [Through/Erase/Layer] <Through>: 0.5

Select object to offset or [Exit/Undo] <Exit>: P26

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P27

Select object to offset or [Exit/Undo] <Exit>: P28

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P29

Select object to offset or [Exit/Undo] <Exit>: P30

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P31

Select object to offset or [Exit/Undo] <Exit>:

Command:

Figure Step 9

Step 10

Using what you already learned, trim the lines to finish the bottom cutout. (Figure Step 10A and 10B)

Figure Step 10A
Figure Step 10B

Step 11

Enter the OFFSET command, as shown below, to offset the inside feature. (Figure Step 11A and 11B)

Command: O

Current settings: Erase source=No Layer=Source OFFSETGAPTYPE=0

Specify offset distance or [Through/Erase/Layer] <Through>: 0.25

Select object to offset or [Exit/Undo] <Exit>: P32

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P33

Select object to offset or [Exit/Undo] <Exit>: P34

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P33

Select object to offset or [Exit/Undo] <Exit>: P35

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P33

Select object to offset or [Exit/Undo] <Exit>: P36

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P33

Select object to offset or [Exit/Undo] <Exit>: P37

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P33

Select object to offset or [Exit/Undo] <Exit>: P38

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P33

Select object to offset or [Exit/Undo] <Exit>: P39

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P33

Select object to offset or [Exit/Undo] <Exit>: P40

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P33

Select object to offset or [Exit/Undo] <Exit>:

Command:

Figure Step 11A
Figure Step 11B
USER TIP: It is faster to draw circles than it is to draw arcs. To improve your drawing speed, when an arc is required draw a circle instead. Then trim the circle to complete the required arc.

Step 12

Use the ID command to establish a lastpoint. Enter the CIRCLE command immediately following to insert the four circles using the lastpoint as a reference. (Figure Step 12)

Command: ID

Specify point: (end) P41

X = 1.5000

Y = 4.000

Z = 0.0000

(The ID command establishes a known reference point or an @ or lastpoint.)

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @0.75,1.25

(Now the @ can be used to measure the center of the circle from the end of the line selected in the ID command.)

Specify radius of circle or [Diameter]: D

Specify diameter of circle: 0.25

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @1,0

Specify radius of circle or [Diameter] <0.1250>: (Accept the default.)

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @0,1

Specify radius of circle or [Diameter] <0.1250>: (Accept the default.)

Command: C

CIRCLE Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @-1,0

Specify radius of circle or [Diameter] <0.1250>: (Accept the default.)

Command:

AUTHOR’S COMMENTS: Using the ID command to set a reference point is a very useful tool for you. Once you pick an ID point, ignore the actual coordinates. On the next command, use an @ to locate a coordinate location from the ID point. Make sure you understand the concept.

Figure Step 12

Step 13

Change the layer of the objects that you want to reside on layer: Object.

Step 14

Freeze layer: Construction and your drawing should appear as shown in the figure. (Figure Step 14)

Figure Step 14

Step 15

Save and close the drawing.

WORKALONG: Drawing Construction Techniques

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 15-2. (Figure Step 2)

Figure Step 2

Step 3

Create the layers: Object and Construction. Set layer: Construction as the current layer.

Step 4

Using Figure Step 2 as an reference, draw lines to construct the perimeter of the object. (Figure Step 4)

Figure Step 4

Step 5

Using what you already learned, trim the lines to complete the outline. (Figure Step 5)

Figure Step 5

Step 6

Enter the ID command, as shown below, to establish a lastpoint. Draw the circle using the reference point you established with the ID command. (Figure Step 6)

Figure Step 6

Command: ID

pecify point: (end) P1

X = 2.0000

Y = 5.5000

Z = 0.0000

(The lastpoint or the @ being established.)

Command: C

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: @1,1.5

(The center of the circle is now located using the reference point established in the ID command above. These commands must be entered back to back.)

Specify radius of circle or [Diameter] <2.6770>: D

Specify diameter of circle <5.3539>:

Command:

Step 7

Enter the OFFSET command, as shown below, to insert the inside offsets. (Figure Step 7)

Command: O

(Shortcut for the OFFSET command)

Current settings: Erase source=No Layer=Source OFFSETGAPTYPE=0

Specify offset distance or [Through/Erase/Layer] <0.00>: 0.75

(Setting the offset distance.)

Select object to offset or [Exit/Undo] <Exit>: P2

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>: P3

(First the object is selected (P2) and then the side of the object (P3) to place the offset. The location for P3 can be anywhere as long as it is above the line to be offset.)

Select object to offset or [Exit/Undo] <Exit>:

(With what you already learned, finish the other two offsets as shown in Figure Step 7.)

Command:

Figure Step 7

Step 8

Enter the CIRCLE command, as shown below, to insert a circle by snapping its center to the intersection of the offset lines. (Figure Step 8)

Command: C

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: (int) P8

(Snap to locate the center of the circle at the intersection of the two offset lines.)

Specify radius of circle or [Diameter] <0.5000>: .25

Command:

Figure Step 8

Step 9

Draw a line between the centers of the circles. (Figure Step 9)

Command: L

Specify first point: (cen) P9

Specify next point or [Undo]: (cen) P10

(Draw a construction line by snapping to center point of the circles.)

Specify next point or [Undo]:

Command:

Figure Step 9

Step 10

Extend the construction line to the circle`s circumference. (Figure Step 10A and 10B)

Command: EX

Current settings: Projection=UCS, Edge=Extend

Select boundary edges …

Select objects or <select all>: P11 1 found

Select objects:

(Press enter or space.)

Select object to extend or shift-select to trim or

[Fence/Crossing/Project/Edge/Undo]: P12

Select object to extend or shift-select to trim or [Fence/Crossing/Project/Edge/Undo]:

Command:

Figure Step 10A
Figure Step 10B
AUTHOR’S COMMENTS: The construction line was drawn from center to center and then extended to the circumference of the circle to locate the tangent point for the arc to be inserted. A line between centers locates the tangent point of the arcs.

Step 11

Draw a circle snapping to the center of the large circle for its center location and snapping to the intersection of the construction line and the lower circumference of the small circle for the radius. (Figure Step 11)

Figure Step 11
AUTHOR’S COMMENTS: If possible, always show AutoCAD a measurement instead of entering the number on the keyboard. Always snap to exiting geometry when you do this.

Step 12

Using the same principle that you learned in Step 11, insert the other two circles. Ensure that you snap one circle to the center of the small circle and the other to the intersection of the tangent line and circle circumference. (Figure Step 12A and 12B)

Figure Step 12A
AUTHOR’S COMMENTS: Circles were used rather then arcs because it is easier to draw circles than arcs. Once the circle is drawn, it can easily be trimmed to complete the arc. This is a much faster drawing technique.
Figure Step 12B
AUTHOR’S COMMENTS: In Step 11 and 12, you are showing AutoCAD the radius of the circles by snapping to the intersection of the construction line and circle. Whenever you can, always show AutoCAD and distance rather then typing it on the keyboard.

Step 13

Draw a circle locating its center at the intersection of the large circle’s centerline and the horizontal construction line. (Figure Step 13)

Command: C

Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: (int) P15

Specify radius of circle or [Diameter]: .25

Command:

Figure Step 13

Step 14

Using what you already learned, trim the circles to complete the slot. (Figure Step 14)

Figure Step 14

Step 15

Enter the LINE command, as shown below, to draw a line from the center of the larger circle and snapping perpendicular to the inclined line. (Figure Step 15)

Command: L

Specify first point: (cen) P16

Specify next point or [Undo]: perp to P17

(It is much faster to type in the osnap mode perp then setting it in Autosnap.)

Specify next point or [Undo]:

Command:

Figure Step 15

Step 16

Using what you already learned, offset the lines to create top feature. (Figure Step 16)

Figure Step 16

Step 17

Trim the lines to complete the top cutout. (Figure Step 17)

Figure Step 17

Step 18

Change the layer of the objects to layer: Object. Freeze layer: Construction to complete the drawing. (Figure Step 18)

Figure Step 18

Step 19

Save and close the drawing.

Key Principles

Key Principles in Module 15

  1. The OFFSET command is a very useful command. When used at the right times, it will improve your drawing speed and change the way you construct objects in AutoCAD.
  2. When a drawing object is offset, the newly constructed offset drawing object will reside on the same layer as the original object, regardless of the current layer.
  3. The ID command can be used to established a known reference point or an @. The reference point can then be used, in the next command, to measure from.

Lab Exercise 15-1

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 15-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

AUTHOR’S COMMENTS: Do not delete the construction lines.

 

Figure Step 1B Completed Drawing

Step 2

Set the insertion units and check the drawing’s accuracy.

Step 3

Turn layer: Key off and freeze layer: Construction.

Step 4

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Draw the line perpendicular to inclined line and then offset the inclined line. Draw a circle with its center located at the intersection of the lines. Offset the perpendicular line using the radius of the circle as the distance and trim. (Figure Hint 1)

Figure Hint 1

Hint 2

Insert offset lines as construction lines to locate the centers of the three circles. Then draw the lines tangent to the circles. (Figure Hint 2)

Figure Hint 2

Hint 3

The figure shows the construction lines. (Figure Hint 3)

Figure Hint 3

Lab Exercise 15-2

Time allowed: 60 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 15-2 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A

AUTHOR’S COMMENTS: Do not delete the construction lines.

Step 2

Set the insertion units and check the drawing’s accuracy.

Step 3

Turn layer Key off and freeze layer Construction.

Step 4

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.

Figure Step 1B
Completed Drawing

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hint. If you get stuck and cannot complete it on your own, use the following hint to help you.

Hint 1

See the figure and the following seven steps:

Figure Step 1

Step 1

Draw a construction line from the center of the bottom circle to the center of the upper circle.

Step 2

Extend the line to the upper circumference of the circle.

Step 3

Draw circles using the intersection of the tangent line and circle to show AutoCAD the radius.

Step 4

Draw the bottom circle at the intersection of the construction circle and line.

Step 5

Trim the circles.

Step 6

Draw the inner circles.

Step 7

Offset the arcs and trim to complete. (Figure Hint 1)

Lab Exercise 15-3

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 15-3 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Door All lines Blue

Step 1

Set the LIMITS as follows:

The lower left corner to: 0.0,0.0

The upper right corner to: 100,150

Step 2

Enter the ZOOM Extents command.

Step 3

Draw the object shown in the figures using the layering scheme. (Figure Step 3A, 3B, and 3C)

Figure Step 3A
Figure Step 3B Exterior Door
Figure Step 3C
Completed Drawing

Step 4

Set the insertion units and check your drawing with the key. Turn layer: Key off and freeze layer: Construction.

Step 5

Save and close the drawing.

16

Module 16: Competency Test 3 Open Book

Learning Outcomes

When you have completed this module, you will be able to:

  1. Within a one-hour time limit, complete a written exam and a lab exercise without the aid of a key.

The AutoCAD 2D book was written with competency based modules. What that means is that  you have not completed each module until you have mastered it. The Competency Test module contains multiple choice questions and a comprehensive lab exercise to test your mastery of the  set of modules that you completed. There are no answers or keys supplied in a Competency Test module since it is meant to be checked by your instructor.  If there are any parts of this module   that you have trouble completing, you should go back and reread the module or modules  containing the information that you are having trouble with. If necessary, redo as many lab exercises required until you fully understand the material.

If you are Completing this book:

Multiple Choice Questions

Select the BEST answer.

  1. Objects can be trimmed and extended in the same command. After it is trimmed or extended, depending on the initial command entered, which key can be pressed to apply the opposite command?
    1. Shift
    2. Alt
    3. Esc
    4. Ctrl
    5. Space
  2. What extension does AutoCAD automatically add to the users assigned drawing name when a drawing is saved?
    1. .drw
    2. .dgw
    3. .drg
    4. .dwg
    5. .dgn
  3. Which one of the following statements best describes a good use for the ID command?
    1. To extend an object to where it intersects another
    2. To trim an object to where it intersects another
    3. To insert a tangent
    4. To change the properties of an
    5. To set a reference
  4. What command is used to change the global linetype scale for the current drawing?
    1. LINE
    2. PLINE
    3. LTSCALE
    4. LINETYPE
    5. POLYGON
  5. Which one of the following best describes a crossing window when selecting objects?
    1. Selects all objects totally inside the window but not the ones that it crosses.
    2. Selects all objects that it crosses and the ones outside the window.
    3. Selects all objects totally inside the window and the ones it crosses.
    4. Selects only the objects that totally cross the window.
    5. Selects all the objects that are outside the window.
  6. What type of AutoCAD drawing object does the FILLET command insert?
    1. circle
    2. pline
    3. arc
    4. line
    5. point
  7. What command is used to insert a tangent arc between two lines?
    1. POLYGON
    2. FILLET
    3. LINE
    4. TRIM
    5. EXTEND
  8. What layer will the newly constructed drawing object reside on when it is created using the OFFSET command? Select the BEST answer.
    1. It won’t be on any layer.
    2. The same layer as the object being offset.
    3. On the layer you specify in the command.
    4. The current Layer
    5. Layer zero
  9. Which one of the following statements best describes the OFFSET command?
    1. Creates an object perpendicular to an existing object at a specified distance.
    2. Creates an object tangent to an existing object at a specified distance.
    3. Creates an object parallel to an existing object at a specified distance.
    4. Creates an object where it intersects an existing object at a specified distance.
    5. Creates an object at the same location as the existing object.
  10. What command is used to insert a line tangent to two circles?
          1. FILLET
          2. INSERT
          3. LINE
          4. EXTEND
          5. POLYGON

Lab Exercise 16-1 OPEN BOOK

Drawing Name Template Units
AutoCAD 2D Lab 16-1 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Draw the object shown in the figure. (Figure Step 1A and 1B)

Figure Step 1A
Completed Drawing
Figure Step 1B

Step 2

Draw all construction objects on layer: Construction. When complete, freeze layer: Construction.

Step 3

Save and close the drawing.

AUTHOR’S COMMENTS: There is no key for this lab. Do not delete the construction objects.

IV

Part 4

17

Module 17: Inquiry and Measurement

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe the geometry of a right angle triangle.
  2. Describe a point, point styles, and object snap mode node.
  3. Apply the system variable SNAPANG to rotate the graphic cursor.
  4. Apply the ORTHO, POINT, DIVIDE, and MEASURE commands.
  5. Apply the UNITS, DIST, and PROPERTIES commands to set the display units, make inquiries about drawing objects, measure distances, and angles.

Geometry Lesson: A Right Angle Triangle

Figure 17-1 and 17-2 show the geometry of a right angle triangle. Understanding this theory will help you to complete your AutoCAD drawings.

Figure 17-1
Geometry of a Right Angle Triangle
Figure 17-2
Geometry of a Right Angle Triangle

Geometry Lesson: Using Circles to Measure

When a measurement is required along an inclined line as shown in Step 1, Figure 17-3, the OFFSET command cannot easily be used to make that measurement. The best method of making the measurement is by drawing a construction circle with a 1 unit radius. Use the end of the inclined line as the center location for the circle. All points on the circumference of the circle will be the radius distance (1 unit) from the center of the circle as shown in the Step 2. Draw the 0.60 diameter circle locating its center at the intersection of the construction circle and the inclined line as shown in the Step 3.

Step 1                                                          Step 2                                                            Step 3
Figure 17-3
Using Circles to Measure

Points

A point is an AutoCAD drawing object that is one pixel in size. Its only geometry property is one XY coordinate.

Point Style

Since a point is nothing more then one pixel in size, it will not display very well in the drawing. If it is located under an existing drawing object, it will not be visible at all. Points can be set to display with an assigned style to make them easier to see and use. The point style for the current drawing is set with the Point Style dialogue box. To open the Point Style dialogue box, select Point Style in the Format Pull-down menu, See Figure 17-4 and 17-5. The size of the points can be set relative with the screen size or an absolute size. To display the points style at the correct size, when the point size is set relative to the screen, the drawing must be regenerated using the REGEN command.

Figure 17-4
Point Style
Figure 17-5
Point Style Dialogue Box
Figure 17-6
Object Snap Mode – Node

AutoCAD Command: POINT

The POINT command is used to insert a point.

Shortcut: PO

Draw Toolbar
Draw Pull-down
Home Ribbon

Rotating the Crosshairs

The crosshairs can be rotated to any angle. Its default rotation angle is 0 degrees, as shown in Figure 17-7. When the rotation angle is 0 degrees, the X axis is horizontal and the Y axis is vertical. There are times when it can be very helpful if the crosshairs are rotated to an angle other than 0 degrees, as shown in Figure 17-8. The SNAPANG system variable is used to set the rotation angle of the crosshairs.

Figure 17-7
Crosshairs in The Normal Position Rotated 0 degrees
Figure 17-8 Crosshairs Rotated 45 degrees
MUST KNOW: It can be very confusing if SNAPANG is set to 90, 180, or 270 degrees since the crosshairs looks just like the default or 0 degrees. You can check its setting by entering the SNAPANG system variable on the command line and ensure it is set to 0.

The DIVIDE Command

The DIVIDE command is used to divide a drawing object by inserting points on the object at calculated XY locations. It does not change the object in any way, it simply inserts points on it. It is important that the current layer is set to layer Construction when the DIVIDE command is used. That way, the points can be easily isolated from the object it is dividing. On lines and arcs, the DIVIDE command starts calculating from the endpoint of the selected object.

The DIVIDE command works different when dividing circles. Since a circle does not have an endpoint, the DIVIDE command will place the first point where the positive X axis of the crosshairs intersects the circle.

The MEASURE Command

The MEASURE command is used to divide a drawing object by inserting points on the object at specified distances along the object. It does not change the object in any way, it simply inserts points on it. It is important that the current layer is set to layer Construction when the MEASURE command is used. That way, the points can easily be isolated from the object being measured. The MEASURE command always starts the first measurement from the closest endpoint to the location where the object is selected.

The MEASURE command works different when measuring circles. Since a circle does not have an endpoint, the MEASURE command will start measuring at the point where the positive X axis of the crosshairs intersects the circle.

AutoCAD Command: ORTHO

The ORTHO command is used to lock the crosshairs to allow it to move only horizontal or vertical. When enabled, it applies to most commands. The current Ortho mode is displayed on the Status bar. The function F8 key toggles ortho mode off and on.

Shortcut: F8

AutoCAD Command: DIVIDE

The DIVIDE command is used to insert points an equal distance apart by dividing the length of the drawing object selected by the number of divisions entered. The object being divided is not changed in any way by the command.

Shortcut: DIV

Draw Pull-down
Home Ribbon

AutoCAD Command: MEASURE

The MEASURE command is used to insert points on a drawing object at a specified distance. The object being measured is not be changed in any way by the command.

Shortcut: ME

Draw Pull-down

WORKALONG: Using the POINT, DIVIDE and MEASURE Commands

Step 1

Start a new drawing using the template: 2D English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 17-1. (Figure Step 2)

Figure Step 2

Step 3

Create the layers: Object and Construction. Set layer: Construction as the current layer.

Step 4

Using what you learned earlier in the book, refer to Figure Step 2 and draw lines around the perimeter of the object. (Figure Step 4)

Figure Step 4

Step 5

From the Format Pull-down menu, select Point Style . This will open the Point Style dialogue box. Select the point style (center with black background) as shown in the figure. Set the Point Size to 3% and enable Set Size Relative to Screen. (Figure Step 5A and 5B)

Figure Step 5A
Figure Step 5B

AUTHOR’S COMMENTS: Setting the point relative to the screen means that regardless of the zoom factor of the screen, the points will always display the same size. You must execute the REGEN command to force AutoCAD to display the points size relative to the current zoom factor.

Step 6

Enter the DIVIDE command, as shown below, and select the inclined line on the right. (Figure Step 6A and 6B)

Command: DIVIDE

Select object to divide: P1

Enter the number of segments or [Block]: 8

Command:

Figure Step 6A
Figure Step 6B

AUTHOR’S COMMENTS: Since the line is divided into 8 segments, seven points are inserted along the line. Points are not inserted at the ends of the lines.

Step 7

As taught earlier in the book, use the OSNAP command to open the Drafting Settings dialogue box. Enable the Node object snap mode. (Figure Step 7)

Figure Step 7
AUTHOR’S COMMENTS: A node is the object snap mode for a point.

Step 8

Press F8 to enable Ortho mode. Check to ensure that it is enabled by checking the Status bar. (Figure Step 8)

Figure Step 8

AUTHOR’S COMMENTS: When Ortho mode is enabled, the LINE command will only draw horizontal or vertical lines assuming that the crosshairs is set to the default angle.

Step 9

Enable object snap and draw 8 horizontal lines by snapping to the points (nodes) as the first point of each line. The length of the lines is not important. (Figure Step 9)

Figure Step 9

AUTHOR’S COMMENTS: You must enter the LINE command 8 times to draw the 8 lines. To work faster, press the Enter or Space key to renter the last command.

Step 10

Draw 7 vertical lines by snapping to the points (nodes) as the first point of each line. The length of the lines is not important. Disable Ortho mode. (Figure Step 10)

Figure Step 10

Step 11

Trim the lines to form the steps as shown in the figure. (Figure Step 11)

Figure Step 11

Step 12

Draw a line by snapping to midpoint on the top left inclined line and the midpoint of the bottom line.

AUTHOR’S COMMENTS: Ensure that you snap to midpoint of both lines.

Step 13

Using the DIVIDE command, divide the line into four segments. (Figure Step 13)

Figure Step 13

Step 14

Set layer: Object as the current layer. Enter the CIRCLE command and draw the three 0.40 diameter circles by snapping to the points (nodes) to locate the center of each circle. (Figure Step 14)

Figure Step 14

Step 15

Set layer: Construction as the current layer.

Step 16

Draw a construction line from the top corner to the bottom corner as shown in the figure. Ensure that you snap to the endpoints of the lines. (Figure Step 16)

Figure Step 16

Step 17

Draw a 0.5 radius construction circle with its center located at the top corner as shown in the figure. Trim the line. (Figure Step 17A and 17B)

Figure Step 17A
Figure Step 17B

Step 18

Enter the MEASURE command, as shown below, to insert points every 0.4325 units along the line. (Figure Step 18)

Command: MEASURE

Select object to measure: P2

Specify length of segment or [Block]: 0.4325

Command:

Figure Step 18
AUTHOR’S COMMENTS: Ensure that you select the line (P2) closest to the end of the line that you want to start the measurement from.

Step 19

The drawing should now appear as shown in the figure. To demonstrate how the point size relative to the screen works, zoom in on your drawing until it fills the screen. Then execute the REGEN command. Notice how the point style size for the points changes. Zoom back out and execute the REGEN command again. (Figure Step 19)

Figure Step 19

Step 20

Set layer: Object as the current layer. Insert 12 – 0.125 diameter circles. One with its center located at the end of the line and the others with their centers located on the points that you inserted with the MEASURE command in Step 18. (Figure Step 20)

Figure Step 20
AUTHOR’S COMMENTS: It helps if you zoom in close to insert the circles.

Step 21

Set layer: Construction as the current layer. Enter the ID command, as shown below, and snap to the endpoint of the bottom line to establish a reference point. (Figure Step 21)

Command: ID

Specify point: (end) P3

X = 1.7500 Y = 4.0000 Z = 0.0000

Command:

Figure Step 21

AUTHOR’S COMMENTS: I used the ID command in Step 21 to establish a reference point. I used that reference point in Step 22 to insert the first point. I inserted it using the @ (the ID reference point or lastpoint) location and measured from it. Ensure that you understand how the reference point was used. Note that it must used in the next command entered after the ID command is executed.

Step 22

Enter the POINT command, as shown below, to draw 3 points at the locations of the center of polygons. (Figure Step 22)

Command: POINT

Current point modes: PDMODE=34 PDSIZE=-3.0000 Specify a point: @.75,1.5

Command: POINT

Current point modes: PDMODE=34 PDSIZE=-3.0000 Specify a point: @0,-1

Command: POINT

Current point modes: PDMODE=34 PDSIZE=-3.0000

Specify a point: @2.25,0

Command:

Figure Step 22

Step 23

Draw three 0.5 diameter circles using the points as the location of the center of the circles. Ensure that you snap to the node when locating the center of each circle. (Figure Step 23)

Figure Step 23

Step 24

Using the DIVIDE command, divide the top left circle into 6 segments. (Figure Step 24)

Figure Step 24
AUTHOR’S COMMENTS: Note how the first point is located along the X axis of the cursor. Six segments was used since a hexagon has six sides.

Step 25

Enter the SNAPANG system variable as shown below to change the angle of the cursor to 90 degrees.

Command: SNAPANG

Enter new value for SNAPANG <0>: 90

Command:

Step 26

Enter the DIVIDE command and divide the bottom left circle into 6 segments. (Figure Step 26)

Figure Step 26

AUTHOR’S COMMENTS: Note how the first point is located along the X axis that has been rotated 90 degrees.

Step 27

Enter the system variable SNAPANG as shown below to change the angle of the crosshairs to 22.5 degrees.

Command: SNAPANG

Enter new value for SNAPANG <90>: 22.5

Command:

Step 28

Enter the DIVIDE command and divide the bottom right circle into 8 segments. (Figure Step 28A and 28B)

Figure Step 28A
Figure Step 28B

AUTHOR’S COMMENTS: Note how the first point is located along the X axis that has been rotated 22.5 degrees. 22.5 degrees is one-half of 45 degrees which is the angle between the corners of an octagon. Eight segments were used since an octagon has 8 sides.

Step 29

Use the SNAPANG system variable, as shown below, to change the angle of the crosshairs to 0 degrees.

Command: SNAPANG

Enter new value for SNAPANG

<22.5>: 0

Command:

AUTHOR’S COMMENTS: Ensure that you always set the SNAPANG system variable back to zero when you have finished working with it.

Step 30

On layer Object, draw the lines for the hexagons and the octagon by snapping from point to point (node to node) as shown in the figure. (Figure Step 30)

Figure Step 30

Step 31

Change the layer of any objects that you want to reside on layer Object. Freeze layer Construction. Your completed drawing should appear as shown in the figure. (Figure Step 31)

Figure Step 31

Step 32

Save and close the drawing.

MUST KNOW: The MEASURE command inserts points at a specified distance. It starts measuring at the end of the object nearest where it is selected. It may not end up with an equal distance at the other end of the object. Make sure that the current layer is Construction before you execute this command to ensure that the points will be easily to isolate from the object it is measuring.

Making Inquiries

The DIST and PROPERTIES commands are used to measure distances, find sizes, and locations of drawing objects. Before using these commands, it is important to understand the importance of the UNITS command.

Displaying Units

AutoCAD stores the drawing object’s properties and locations to a very high degree of accuracy. When the drawing object’s properties are displayed, either on the Command Line or in the Properties window, AutoCAD uses the setting in the Drawing Units dialogue box to display these properties rounded off as per the current settings. The answers are always displayed in drawing units but the precision and format of the answers is controlled by the settings in the Drawing Units dialogue box.

AutoCAD Command: UNITS

The UNITS command is used to open the Drawing Units dialogue box. It is used to set the way AutoCAD displays inquiries or drawing object properties.

Shortcut: UN

 

Format Pull-down

AutoCAD Command: DIST

The DIST command is used to measure distances between two XY coordinate locations.

Shortcut: DI

Inquiry Toolbar
Tool Pull-down
Home Ribbon

Geometry Lesson: Finding the Shortest Distance Between the Circumference of Two Circles

To find the shortest distance between the circumference of two circles, draw a construction line from the center of one circle to the center of the other as shown in Step 1. Measure the distance between the intersections of the lines and circles as shown in Step 2. If the line is trimmed as shown in Step 3, the length of the line is the shortest distance between the circle’s circumference. See Figure 17-9.

Step 1                                                     Step 2                                                   Step 3
Figure 17-9
Finding the Shortest Distance Between the Circumference of two Circles

WORKALONG: Using Inquiry Commands

Step 1

Open the drawing: AutoCAD 2D Workalong 17-1 . Using the SAVEAS command, save the drawing with the name: AutoCAD 2D Workalong 17-2. (Figure Step 1)

Figure Step 1

Step 2

Enter the UNITS command. It will open the Drawing Units dialogue box. Set the dialogue box to match the figure. (Figure Step 2)

Figure Step 2

Step 3

Enter the DIST command, as shown below, to measure the distance between the center of the circle and the end of the line as shown in the figure. Ensure that you snap to the center of the circle and the endpoint of the line. (Figure Step 3)

Command: DIST

Specify first point: (cen) P1

Specify second point: (end) P2

Command:

Figure Step 3

Step 4

Press F2 to open the Text window. The answer to the DIST command will display as shown in the figure. (Figure Step 4)

Figure Step 4
AUTHOR’S COMMENTS: The measured distance is 1.393831 units. The angle of the line is 174.21 degrees. For an explanation of delta X and delta Y, see the Geometry Lesson: A Right Triangle.
AUTHOR’S COMMENTS: Note that AutoCAD displays the answers to the DIST command to 6 decimal places. That is the precision that was set in the Length Precision in the Drawing Units dialogue box in Step 2.

Step 5

Press F2 to close the Text window.

Step 6

Draw a construction line from the center of circle to center of circle as shown in the figure. Ensure that you snap to the centers of the circle at both ends. Enter the DIST command as shown below to measure the shortest distance between circumferences of the circles by snapping to intersection of the construction line and the circles. (Figure Step 6)

Command: DIST

Specify first point: (int) P3

Specify second point: (int) P4

Command:

Figure Step 6

Step 7

Press F2 to open the Text window. The answer to the DIST command will display as shown in the figure. (Figure Step 7)

Figure Step 7

Step 8

Trim the construction line as shown in the figure. (Figure Step 8)

Figure Step 8
MUST KNOW: AutoCAD stores the accuracy of the drawing object’s properties to a very high degree. The UNITS command is used to set the format and precision which instructs AutoCAD how to display answers in the Properties window and to the users inquiry commands.

Step 9

Open the Properties window. Without entering a command, select the line. The Properties window will display the length of the line. (Figure Step 9)

Figure Step 9

AUTHOR’S COMMENTS: The length of the line (0.622819) and the angle of the line (111.27 degrees or 111.27 + 180.00 = 291.27) should match the answers in the DIST command in Step 7.

Step 10

Set the Drawing Units dialogue box, as shown in the figure. (Figure Step 10)

Figure Step 10

AUTHOR’S COMMENTS: Note that the Length Precision is set to 8 decimals and the Angle Type is set to display in Degree/Minutes/Seconds with a Precision of no decimals.

Step 11

Draw a line from the center of the circle to the vertex on the hexagon as shown in the figure. (Figure Step 11)

Figure Step 11

Step 12

After trimming the line, select it. Check its length and angle in the Properties window. (Figure Step 12)

Figure Step 12

AUTHOR’S COMMENTS: Your answers and the ones in the figure should match. Note the angle is now displayed in the Degree/Minutes/Seconds. If you drew the line from the vertex of the hexagon to the center of the circle, the angle will be 15d45’48”. Both answers are correct since each line always has two angles depending which direction the line was drawn.

Step 13

Turn layer: Construction off. Enter the ID command and snap to the center of the circle. Press F2 to open the Text window. (Figure Step 13A and 13B)

Figure Step 13A
Figure Step 13B

Step 14

Select the circle as shown in the figure. Take note that the Properties window displays the XY center location plus the radius, diameter, circumference, and area of the circle. (Figure Step 14)

Figure Step 14

AUTHOR’S COMMENTS: Note that the Length Precision is set to 8 decimals.

Step 15

With the Properties window open, select the line as shown in the figure. Figure Step 15)

Figure Step 15

Step 16

Save and close the drawing.

Geometry Lesson: Finding the Centroid of any Triangle

To find the centroid (geometrical center) of any triangle, draw construction lines from each vertex to the midpoint of the opposite line of the triangle. The centroid of the triangle is the intersection of the three lines. See Figure 17-9.

Figure 17-9
Finding the Center of a Triangle

Key Principles

Key Principles in Module 17

  1. A point is an AutoCAD drawing object that is one pixel in size.
  2. A node is the object snap mode for a point.
  3. AutoCAD stores the accuracy of the drawing object’s properties and locations to a very high degree. The UNITS command is used open the Drawing Units dialogue box where the you can set the format of how AutoCAD displays these properties and locations.
  4. The DIVIDE command insert points on the object by dividing the object’s length or perimeter into an equal number of segments specified by the user.
  5. The MEASURE command inserts points on an object at a user specified distance.

Lab Exercise 17-1

Time allowed: 45 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 17-1 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

AUTHOR’S COMMENTS: Do not delete the construction lines. HOR = Horizontal and VER = Vertical.
Figure Step 1A
Figure Step 1B
Completed Drawing

Step 2

Set the insertion units and check your drawing with the key.

Step 3

Turn layer: Key off and freeze layer: Construction.

Step 4

Using either the DIST command or the Properties window, find the following answers with the precision of 8 decimal places:

  1. Length of arc A: ______________________
  2. Distance from the center of circle C to center of circle E. ______________________
  3. Shortest distance from corner B to the circumference of circle C. ______________________
  4. The circumference of circle D: ______________________

(Check your answers on the key)

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Using the DIVIDE command, divide the large circle into 26. (Figure Hint 1)

Figure Hint 1

Hint 2

Rotate the cursor 7.5 degrees and divide the 40 diameter circle into 5. (Figure Hint 2)

Figure Hint 2

Hint 3

Rotate the cursor 30 degrees and divide the 75 diameter circle into 6. (Figure Hint 3)

Figure Hint 3

Hint 4

Draw 6 – 20 diameter circles locating their centers on the points. (Figure Hint 4)

Figure Hint 4

Hint 5

To draw the polygons, rotate the cursor to the appropriate angle as shown in the list below. (Figure Hint 5A and 5B)

Triangle = 90 degrees

Square = 45 degrees

Pentagon = 90 degrees

Hexagon = 90 degrees

Heptagon = 90 degrees

Octagon = 22.5 degrees

Figure Hint 5A
Figure Hint 5B

Lab Exercise 17-2

Time allowed: 50 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 17-2 2D English Inches
Layering Scheme
Layer Name Objects on Layer Color
Construction Construction objects 253
Object All objects Red

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

Step 2

Set the insertion units and check your drawing with the key.

Step 3

Turn layer: Key off and freeze layer: Construction.

AUTHOR’S COMMENTS: Do not delete the construction lines.

 

Figure Step 1A
Completed Drawing
Figure Step 1B

AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Using the DIVIDE command, divide the inclined line into 12. (Figure Hint 1)

Figure Hint 1

Hint 2

Construct the steps using ortho mode. (Figure Hint 2)

Figure Hint 2

Hint 3

Trim the steps and change the layer they reside on to layer: Object. Offset the inclined line and draw a circle to measure the distance along the inclined line. (Figure Hint 3)

Figure Hint 3

Hint 4

Draw the triangle by offsetting the three outsides 0.75 inches as shown in the dimensioned drawing. Using the Geometry Lesson: Finding the Centroid of any Triangle, find the centroid of the triangle and draw a 0.35 diameter circle using the intersection of the lines to locate its center. (Figure Hint 4)

Figure Hint 4

Hint 5

Offset the outside lines of the triangle 0.20 inches towards the center. (Figure Hint 5)

Figure Hint 5

Hint 6

Offset the inside lines 0.10 inches on each side. (Figure Hint 6)

Figure Hint 6

Hint 7

Trim all lines and the circle. Fillet all corners using a radius of 0.05 inches. The fillets should always be inserted last. (Figure Hint 7)

Figure Hint 7

Hint 8

Change the layer of all objects to layer: Object. (Figure Hint 8)

Figure Hint 8

18

Module 18: Layouts – Part 1

Learning Outcomes

When you have completed this module, you will be able to:

  1. Describe Model space and Paper space and explain how they are used in AutoCAD.
  2. Describe a Layout and explain how they are used in an AutoCAD drawing.
  3. Apply the MSPACE and PSPACE commands to change the working space.
  4. Describe a viewport and explain how to create, edit, lock, and set the viewport scale.
  5. Apply the MVIEW command to create viewports on layout drawings.

Model and Paper Space

Up to this point in the book, you have been drawing Model space. In this module, Paper space and layouts will be introduced. The ideal way to work in AutoCAD is to draw all real objects in Model space and draw all objects that not real, in Paper space.

Model space is a limitless three-dimensional space where the real objects of the model are drawn. For example, if you are drawing a house, everything that is part of the house such as the walls, windows, doors, etc. are drawn in Model space. All parts of the house would be drawn at full scale or full size, exactly as they exist in real life.

Paper space is a virtual two-dimensional space where all objects that are related to the plotted piece of paper, called a layout, are drawn. Objects drawn in Paper space are things like the titleblock, border, dimensions, notes, labels, and bills of material. Paper space is also drawn at full size but the units are the same units as the paper, such as inches or millimeters. The Model space units and the Paper space units do not have to be the same in a drawing.

Layouts

A layout represents a sheet of paper on which one or more scaled views of the model is created complete with such thing as dimensions, notes, border, and titleblock. Layouts are drawn in Paper space. They are an important and essential AutoCAD feature and should be used to plot all AutoCAD drawings.

As many layouts as required can be created in a drawing. The AutoCAD 2D book supplies pre- drawn layouts in two template files named ‘ 2D Layout English.dwt ‘ and ‘ 2D Layout Metric.dwt ‘. You can create your own layouts and save them in a drawing or template file. Creating your own templates is taught in the AutoCAD 2D Advanced book.

Model and Layout Tabs

The Model and Layout tabs are located along the bottom of the Graphic window as shown in Figure 18-1 and 18-2. There is only one Model tab in each drawing but there can be an unlimited number of Layout tabs. You can create your own layouts tabs. This taught in the AutoCAD 2D Advanced book.

Figure 18-1
Model – Enabled
Figure 18-2
Module Layout A Layout – Enabled

When the Model tab is enabled, all drawing objects drawn by you will be Model space objects and exist in Model space. When one of the Layout tabs is enabled, as shown in Figure 18-2, the layout drawing will be displayed. In a Layout tab, you can work in either Paper space or Model space.

The Working Space

The current space, which is either Model or Paper, is called the working space. When the MODEL icon is enabled, the working space is Model and when the PAPER icon is enabled, the working space is Paper.

When a Layout tab is enabled, the working space can be changed back and forth between Model or Paper space by toggling the PAPER/MODEL icon in the Status bar. See Figures 18-3 and 18-4. Click the MODEL icon to change the working space to Paper space or click the PAPER icon to change the working space to Model space.

Figure 18-3
Model Space is Currently the Working Space
Figure 18-4
Paper Space is Currently the Working Space

The Paper Space Icon

When a Layout tab is enabled and the working space is Paper, the Paper space icon, as shown in Figure 18-5, will display. When the icon is displayed, it is indicating to you that Paper space is the working space and all objects drawn will be Paper space objects and exist in Paper space only.

If this icon does not display, even when a layout is displayed, all objects drawn will be Model space objects and exist in Model space only.

Figure 18-5 The Paper Space Icon

AutoCAD Command: MSPACE

The MSPACE command is used to change the current working space to Model space.

Shortcut: MS

AutoCAD Command: PSPACE

The PSPACE command is used to change the current working space to Paper space.

Shortcut: PS

Viewports

A viewport is a rectangular or square hole cut through the sheet of drawing paper (the layout) so that the model can be viewed through it. See Figure 18-6. It is a 2D Paper space drawing object. The view of the model can be orientated and scaled. A layout can have an unlimited number of viewports cut through it, all viewing the same model at different scales and orientations.

Each viewport will display all visible objects that exist in Model space. If the model is changed after a viewport is created, the viewport will automatically display the changes since it is merely viewing the model. The orientation and scale of a viewport can be adjusted at any time. After a viewport is set, the display can be locked so that it cannot be accidentally changed. If changes are required, the viewport display must be unlocked before they can be made. It is best to insert the viewport on its own layer and turn that layer off before the drawing is plotted to avoid plotting the viewport drawing object.

Paper space objects like dimensions, notes, titleblocks, borders, and text are then drawn in Paper space on the sheet of paper. They are drawn full size using the same units as the paper is measured.

Figure 18-6
A Viewport

AutoCAD Command: MVIEW

The MVIEW command is used to create a viewport on a layout. It is a Paper space command and the viewport it creates is a Paper space drawing object.

Shortcut: MV

WORKALONG: Working With Layouts

Step 1

Start a new drawing using the template: 2D Layout English.

AUTHOR’S COMMENTS: Ensure that you select the correct template. The templates that you have being using to this point in the book will not be used from this module on. The new templates that you will be using are named: 2D Layout English and 2D Layout Metric.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 18-1.

Step 3

Using what you learned to this point in the book, draw the object shown in the figure on layer: Object. Draw any construction objects on layer: Construction. (Figure Step 3)

Figure Step 3

AUTHOR’S COMMENTS: You will notice that the drawing already contains the layers that you require to complete the lab exercises. They were created in the template file and will save you creating most layers in the drawings in the remaining drawings in this book.

Step 4

Freeze layer: Construction. The drawing should appears as shown in the figure. (Figure Step 4)

Figure Step 4

Step 5

Enter the OPTIONS command to open the Options dialogue box. In the Display tab, compare the settings in the Layout elements area and change them, if necessary, to match the figure. Click OK to close the dialogue box. (Figure Step 5)

Figure Step 5
MUST KNOW: Model space is a limitless three-dimensional space where the real objects of the model are drawn full scale while Paper space is a virtual two-dimensional space where all objects related to the plotted paper drawing are drawn.

Step 6

Enable layout: Module Layout A by clicking it. Your Graphic window should match the figure. (Figure Step 6)

Figure Step 6
AUTHOR’S COMMENTS: A layout is a piece of paper that can be plotted. The model is located behind the paper but cannot be seen until a hole (viewport) is cut in the paper using the MVIEW command. The paper size in Module Layout A is A size or 8 1/2X11 inches.

Step 7

Paper space should be the working space. To check that, ensure that the PAPER icon is enabled on the Status bar. (Figure Step 7)

Figure Step 7

Step 8

Set layer: Viewport as the current layer. Enter the MVIEW command, as shown below, to create a viewport on the layout. (Figure Step 8)

Command: MVIEW

Specify corner of viewport or [ON/OFF/Fit/Shadeplot/Lock/Object/Polygonal/Restore/LAyer/2/3/4] <Fit>: P1

Specify opposite corner: P2

Command:

Figure Step 8

AUTHOR’S COMMENTS: Selecting two opposite corners in the MVIEW command creates a viewport. The locations for P1 and P2 can be selected by eye. Their exact locations are not important. Imagine the viewport as cutting a hole in the piece of paper to view the model located behind the paper. Since a viewport is a drawing object, you can delete it and recreate it if you want to change its size or location. Ensure that you are in Paper space to delete a viewport. The AutoCAD 2D Advanced book teaches you how to resize viewports.

Step 9

Change the working space to Model by clicking the PAPER icon on the Status bar. After you do that, it will display MODEL as shown in the figure. (Figure Step 9A and 9B)

Figure Step 9A
Figure Step 9B

AUTHOR’S COMMENTS: Note that when the working space is Model, the crosshairs will only display inside the viewport (the hole in the paper).

Step 10

Enter the ZOOM Extents command to display all model objects in the viewport. (Figure Step 10)

Figure Step 10

Step 11

Change the working space to Paper space. (Figure Step 11)

Figure Step 11

AUTHOR’S COMMENTS: Note that when the working space is Paper, the crosshairs will display to cover the complete Graphic window. This means that you can draw anywhere in the Graphic window. All objects drawn, while the working space is Paper, will be Paper space objects.

Step 12

Open the Properties window. Without entering a command, select the viewport. It will highlight, as shown in the figure, and grips will display on the four corners. While the viewport is selected, pull down the Standard scale property and set it to 1:2. (Figure Step 12A and 12B)

Figure Step 12A
Figure Step 12B

Step 13

While the viewport is selected, pull down the Display locked property and set it to Yes. (Figure Step 13)

Figure Step 13

AUTHOR’S COMMENTS: When the Display locked property is set to Yes, the viewport cannot be altered by zooming and panning. That means that the scale cannot be changed. It is best to always lock the viewport display after it is set to protect it from accidentally being changed.

Step 14

Your completed layout should appear as shown in the figure. (Figure Step 14)

Figure Step 14

AUTHOR’S COMMENTS: The model in this viewport is set to a scale of 1:2 or one-half size of the original size of the model.

Step 15

Enable the display of layout: Module Layout B. (Figure Step 15)

Figure Step 15
AUTHOR’S COMMENTS: The paper size in Module Layout B is B size or 11X17 inches.

Step 16

Using what was taught in Step 8, enter the MVIEW command, two times, to create two viewports. After creating the viewports, change the working space to Model and click inside the left viewport. Enter the ZOOM Extents command. Click inside the viewport on the right and enter the ZOOM Extents command again. Change the working space to Paper and the layout should appear similar to the figure. (Figure Step 16)\

Figure Step 16

Step 17

Using what was taught earlier in the workalong, select the viewport on the left and set the scale to 2:1. (Figure Step17)

AUTHOR’S COMMENTS: Paper space must be the working space to select the viewport.

Step 18

Change the working space to Model and click inside viewport on the left. (Figure Step 18)

Figure Step 18

Step 19

Without changing the zoom, pan of the model as shown in the figure. Change to Paper space. (Figure Step 19)

Figure Step 19

Step 20

Using what was taught earlier in the workalong, use the Properties window and check to ensure that the scale is still set to 2:1. Lock the display. (Figure Step 20)

Figure Step 20
AUTHOR’S COMMENTS: The model in this layout is set to a scale of 2:1 or two times the size of the original model.

Step 21

Using what was taught earlier in the workalong, zoom and pan the model in the right viewport. Set the Custom scale to 3 and lock the display. (Figure Step 21A and 21B)

Figure Step 21A
Figure Step 21B
Figure Step 21C

 

AUTHOR’S COMMENTS: The model in this layout is set to a scale of 3:1 or three times the size of the original model.

Step 22

Turn layer: Viewport off. Your layout should appears as shown in the figure. (Figure Step 22)

Figure Step 22

Step 23

Save and close the drawing.

Figure 18-7
Layout Paper Sizes
USER TIP: Type your textbox content here.
MUST KNOW: There are two completely different spaces to work in when you are drawing in AutoCAD. They are called Model space and Paper space. The real objects that you are drawing should be drawn in Model space and all other objects that are part of the description of the object, are drawn in Paper space.Objects created in Model space can only be modified when the working space is Model and should alway be drawn at full size using the appropriate model drawing units. Objects drawn in Paper space can only be modified while the working space is Paper. The paper units may differ from the model units.

MUST KNOW: After you use the MVIEW command to create a viewport in the layout, you should always execute the ZOOM Extents command immediately after. Before you enter the ZOOM Extents command, change the working space to Model. After executing the command, you will be able to see all the visible model objects in the viewport. You can then zoom and pan the model to set the desired view.

Zoomed to the Extents
View zoomed and Panned

Key Principles

Key Principles in Module 18

  1. Model space is a limitless three-dimensional space where the real objects of the model are drawn.
  2. Paper space is a virtual two-dimensional space where all objects related to the piece of paper, called a layout, are drawn. Objects drawn in Paper space are things like the titleblock, border, dimensions, notes, labels, and bills of material.
  3. A viewport is a rectangular or square hole cut through a sheet of drawing paper (layout) so that the model can be viewed at a specified scale and orientation.
  4. The current space, which is either Model or Paper, is called the working space. Objects drawn in Model space are model space drawing objects and objects drawn in Paper space are paper space drawing objects.

Lab Exercise 18-1

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 18-1 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Gasket All objects Red

Step 1

Draw the top view of the gasket shown in the figure using the layering scheme. (Figure Step 1A, 1B, and 1C)

Figure Step 1A
Figure Step 1B
Gasket
Figure Step 1C Completed Drawing

Step 2

Set the insertion units and check your drawing with the key. Turn layer: Key off and freeze layer: Construction.

Step 3

In layout: Module Layout A4, on layer: Viewport, create a viewport using the MVIEW command. Pan the model as shown in the figure. Set the scale to 1:1 and lock the display. (Figure Step 3)

Figure Step 3

Step 4

In layout: Module Layout A1, on layer Viewport, create three viewports using the MVIEW command. Pan the model as shown in the figure and set the custom scale of the top left viewport to 1:1, the bottom left viewport to 4:1, and the one on the right to 6:1. Lock the display of all three viewports. (Figure Step 4)

Figure Step 4

Step 5

Turn layer: Viewport off. (Figure Step 5)

Figure Step 5

AUTHOR’S HINTS: When you are setting the viewport scale and a standard scale is not available to you, simply type in the scale number in the Custom scale property as shown in the figure below. In this example the scale of 6:1 is entered as 6. If the scale you want to enter is 1:4, then you enter 0.25 (1 divided by 4). Setting custom scale is taught in a future module aand creating standard scales is taught in the AutoCAD 2D Advanced book.

Lab Exercise 18-2

Time allowed: 40 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 18-2 2D Metric Millimeters
Layering Scheme
Layer Name Objects on Layer Color
Wrench All objects Blue

Step 1

Draw the top view of the wrench shown in the figure using the layering scheme. (Figure Step 1A, 1B, and 1C)

Figure Step 1A
Open End Wrench
Figure Step 1B
Figure Step 1C
Completed Drawing

Step 2

Set the insertion units and check your drawing with the key. Turn layer: Key off and freeze layer: Construction.

Step 3

In layout: Module Layout A4, on layer: Viewport, create a viewport using the MVIEW command. Pan the model as shown in the figure. Set the scale to 1:1 and lock the display. (Figure Step 3)

Figure Step 3

Step 4

In layout: Module Layout A4, on layer: Viewport, create two additional viewports using the MVIEW command. Pan the model as shown in the figure. Set the scale to 2:1 and lock the display. (Figure Step 4)

Figure Step 4
AUTHOR’S HINT: The following steps show how one end of the wrench is constructed: Use the same principles to draw the other end.

Step 1

Draw the construction lines for the circle and center lines. I am showing only one end in the following figures.

Step 2

Offset the inclined center line on each side. On the left side of the wrench the offset distance is 6.5 mm.

Step 3

Extend the top offset line to the vertical center line.

Step 4

Using the end of the line that you just extended as the center, draw a circle with radius of the small arc. On the left side of the wrench it is 13 mm. I drew it in red to help you identify it.

Step 5

Using the intersection of the circle you just drew and the inclined line as the center, draw a circle with the radius of the small arc. On the left side of the wrench it is 13 mm. I drew it in blue to help you identify it.

Step 6

Extend the bottom offset line to the circle.

Step 7

Trim the blue circle. I removed the red circle to help you. You can leave it in your drawing as a construction line.

Step 8

Finish the trim to complete the left side of the wrench.

19

Module 19: Text – Part 1

Learning Outcomes

When you have completed this module, you will be able to:

1 Describe single line text, text style, and text justification.

2 Apply the STYLE, TEXT, and DDEDIT commands to format, insert, and edit single line text.

Text

In this module, formatting, inserting, and editing single line text is taught. Single line text is text that is inserted as a single line, is edited one line at a time, and each line is a individual drawing object. Module 25 teaches multiline text.

Text Style

The STYLE command is used to create and format text styles plus used to set the current text style. A text style contains text properties, is user created, named, and saved in the drawing. As many text styles as required can be created and saved in each drawing. The current text style is the text style that will be assigned to text that is inserted in the drawing using the TEXT command.

A good example to explain text style is to use the text font. Font is a text property that is set in a text style. If you want to change the font of an existing text object on the drawing, the style property of the text must be changed. This is done using Properties window. Simply find the text style assigned to the selected text and then change the font property of that style. All existing text, with that style, will change to reflect the new font assigned. If you only want to change the font of the selected text, defined a new text style with the font required and change the style assigned to the selected text.

All AutoCAD drawings contain a text style named Standard. It is special style that cannot be deleted or purged from the drawing. It should not be used as it may cause problems in the drawing sometime in the future. The reason for this will be taught later in the book. For now, create your own text style or use ones that already exist.

Text Justification

Text justification is a property attached to text objects that locates the text in relation to its insert point selected by the you in the TEXT command. There are many ways to justify text and it is important for you to know how, where, and when to use each one. In this module, the left, middle, and right justified text are taught. Figure 19-1 shows how a text object would justify itself if inserted at the selected locations P1, P2, and P3. If you do not specify a justification when inserting text, the default justification is left.

Figure 19-1 Text Justification

Text Height

Text height is a property assigned to the text drawing object and not to the text style. In almost all cases, the text height property, in the text style, should be set to zero. When it is set to zero, AutoCAD allows you to change the text height of text inserted with that style. It also allows the text style to automatic scale text in a dimension.

AutoCAD Command: STYLE

The STYLE command is used to create, format, and edit text styles. It also is used to set the current text style.

Shortcut: ST

Text Toolbar

 

Format Pull-down

Home Ribbon

AutoCAD Command: TEXT

The TEXT command is used to insert single line text.

Shortcut: TE

Text Toolbar
Draw Pull-down
Home Ribbon

 

Figure 19-2
Object Snap Mode – Insert

AutoCAD Command: DDEDIT

The DDEDIT command is used to edit existing text objects.

Shortcut: Double click the text.

Text Toolbar

 

Modify Pull-down
USER TIP: If a text object is double clicked, the Edit Text dialogue box will open automatically with the text selected, ready to be edited. This is a fast way to edit single line text and almost eliminates the use of the DDEDIT command. Text contents can also be edited in the Properties window.

WORKALONG: Creating Text Styles and Inserting Single Line Text

Step 1

Start a new drawing using the template: 2D Layout English.

Step 2

Save and name the drawing: AutoCAD 2D Workalong 19-1.

Step 3

Enter the STYLE command. It will open the Text Style dialogue box. (Figure Step 3)

Figure Step 3
AUTHOR’S COMMENTS: The Standard text style is a special style that all drawings contain. It cannot be deleted or purged from the drawing. I suggest that you do NOT use it. It is better to create your own styles.

Step 4

Click the New button to open the New Text Style dialogue box. (Figure Step 4)

Figure Step 4

Step 5

Enter the name: Module 19-1 in the Style Name box as shown in the figure. Click OK to save and close the dialogue box. (Figure Step 5)

Figure Step 5

Step 6

Check to ensure that the Current text style is set to: Module 19-1. (Figure Step 6)

Figure Step 6

Step 7

In the Font Name: box, pull down the list and select the font: romans.shx. (Figure Step 7)

Figure Step 7
AUTHOR’S COMMENTS: Once you pull down the font name list, type the first letter of the name of the font you are looking for. In this case, R. That will force the list to jump directly to the font names that begin with the letter R.

Step 8

Do not change any other items. The Text Style dialogue box should now appear as shown in the figure. Click the Close button to save and close the dialogue box. (Figure Step 8)

Figure Step 8
AUTHOR’S COMMENTS: In almost all cases, the text height in the Text Style dialogue box should be set to zero. When it is set to zero, the text height for any text assigned that style can be set and changed to any height you desire. If it is set to a value other then zero, the text height of all text assigned that text style property will not be allowed to be changed.

Step 9

Enable layout: Module Layout A. (Figure Step 9)

Figure Step 9

Step 10

Set layer: Text as the current layer.

Step 11

Enter the TEXT command, as shown below, to insert text on the drawing. (Figure Step 11)

Command: TEXT

Current text style: “Module 19-1” Text height: 0.2000

(The defaults will display. Ensure that Module 19-1 is the current default style.)

Specify start point of text or [Justify/Style]: 1,9

(This is the insert point. By default, the text will be left justified)

Specify height <0.2000>: 0.35

Specify rotation angle of text <0>:

(Press Enter to leave the rotation angle at 0 degrees.)

THIS IS MODULE 19

(Type the text and press Enter)

(Press Enter again)

Command:

Figure Step 11

Step 12

Enter the TEXT command, as shown below, to insert text on the drawing. (Figure Step 12)

Command: TE

Current text style: “Module 19-1” Text height: 0.3500 Specify start point of text or [Justify/Style]: 0.5,3.5 Specify height <0.3500>: 0.25

Specify rotation angle of text <0>: 45

THIS IS STYLE MODULES 19-1

(Press Enter)

INSERTED AT 0.25 TEXT HEIGHT

(Press Enter)

IT IS ROTATED AT 45 DEGREES

(Press Enter)

Command:

Figure Step 12

Step 13

Enter the TEXT command, as shown below, to insert text on the drawing. (Figure Step 13)

Command: TE

Current text style: “Module 19-1” Text height: 0.0250

Specify start point of text or [Justify/Style]: J

Enter an option [Align/Fit/Center/Middle/Right/TL/TC/TR/ML/MC/MR/BL/BC/BR]: R

(Setting a right justification.)

Specify right endpoint of text baseline: 5,2

Specify height <0.2500>: 0.175

Specify rotation angle of text <45>: 0

THIS TEXT IS RIGHT JUSTIFIED.  (Press Enter)

Command:

Figure Step 13

Step 14

Save and close the drawing.

WORKALONG: Editing Single Line Text

Step 1

Open the drawing: AutoCAD 2D Workalong 19-1.

Step 2

Using the SAVEAS command, save it with the name: AutoCAD 2D Workalong 19-2.

Step 3

Using what you learned in the first workalong, enter the STYLE command and create a new text style named: Module 19-2. Set the text style to match the figure. (Figure Step 3)

Figure Step 3
USER TIP: The Style toolbar at the top of you Graphic window is very handy to execute the STYLE command or set the current text style.

Step 4

Enable the display of layout: Module Layout A. (Figure Step 4)

Figure Step 4

Step 5

Double click the text at the top of the drawing to enter edit mode. (Figure Step 5)

Figure Step 5

Step 6

With the text in edit mode, change the text to read THIS IS EDITED TEXT. (Figure Step 6)

Figure Step 6

USER TIP: If the text editor does not open when you double click the text object, enter the DBLCLKEDIT system variable, as shown below, and set to ON.

Command: DBLCLKEDIT

Enter new value for DBLCLKEDIT <OFF>: ON

Command:

MUST KNOW: In the Text Style dialogue box, the text height should almost always be set to zero. When it is set to zero, AutoCAD allows you to change the text height of text assigned that style. It also allows the text style to automatic scale text in a dimension.

Step 7

Open the Properties window. Select the three lines of text as shown in the figure. While the text is selected, pull-down the Style property list and select layout: Module 19-2. Press Enter and then Esc to clear the selected text. (Figure Step 7A and 7B)

Figure Step 7A
Figure Step 7B

Step 8

Select the bottom line of the rotated text as shown in the figure. In the Properties window, change the Rotation angle property to 30. (Figure Step 8)

Figure Step 8

Step 9

While the text is selected, change the Contents property as shown in the figure. (Figure Step 9)

Figure Step 9

Step 10

Select the bottom text line. In the Properties window, change the Justification property to Middle, the Height property to 0.2, and the Contents property as shown in the figure. (Figure Step 10A, 10B, and 10C)

Figure Step 10A
Figure Step 10B
Figure Step 10C

Step 11

Double click the text and edit it as shown in the figure. (Figure Step 11)

Figure Step 11

Step 12

Your completed layout should appear as shown in the figure. (Figure Step 12)

Figure Step 12

Step 13

Save and close the drawing.

USER TIP: When using a pull down window with lists, such as the font list in the Text Style dialogue box, and you know the name of the font you want to use, enter the first letter of the font after you pullthe list down. The list will jump to the font names that start with that letter. This should work for all software written to Window’s standards.

MUST KNOW: The Standard text style is a special style and cannot be deleted or purged out of the drawing. It is best NOT to use this text style in your drawings. It is much better to create your own styles.
USER TIP: The Styles toolbar has a Pull-down menu that you can use to set the current text style. This is a great feature to quickly change the current text style to speed drawing production.
USER TIP: The text height, style, rotation angle, content, justification, width factor, and obliquing angle are text properties and can be changed in the Properties window. The font is controlled by the style property. If you want to change the font of an existing text object, change its style. Simply open the Properties window and single click the text to edit its properties.

Key Principles

Key Principles in Module 19

  1. Single line text is text that is inserted as a single line, can be edited one line at a time, and each line is its own drawing object.
  2. The text style defines the text properties, like the font and width of the text. To change the font of a text, its style property must be changed.
  3. The text height should almost always be set to zero in the Text Style dialogue box.
  4. The Standard text style is a special text style that is contained in every drawing. It cannot be deleted or purged. It is best not to use this text style in your drawings.
  5. The text height, style, rotation angle, content, justification, width factor, and obliquing angle are text properties and can be changed in the Properties window.
  6. To edit text, double click it. This will automatically open the Edit Text dialogue box with the selected text, ready to be edited. This is a very fast way to edit single line text and almost eliminates the use of the DDEDIT command. Text contents can also be edited in the Properties window.

Lab Exercise 19-1

Time allowed: 60 minutes.

Drawing Name Template Units
AutoCAD 2D Lab 19-1 2D Layout English Inches

Step 1

On layer: Object, draw the object shown in the figure. (Figure Step 1A and 1B)

AUTHOR’S COMMENTS: Do not delete the construction objects.
Figure Step 1A
Figure Step 1B Completed Drawing

Step 2

Draw all construction objects on layer: Construction.

Step 3

Set the insertion units and insert the key. Check the drawing for accuracy.

Step 4

Turn layer: Key off and freeze layer: Construction.

Step 5

In layout: Module Layout A, on layer: Viewport, create a viewport using the MVIEW command. Pan the model as shown in the figure. Set the scale to 1:1 and lock the display. (Figure Step 5)

Figure Step 5

Step 6

In layout: Module Layout B, on layer: Viewport, create two viewports using the MVIEW command. Pan the model as shown in the figure and set the custom scale of the left viewport to 1.5:1 and the one on the right to 4:1. Lock the display of both viewports. (Figure Step 6)

Figure Step 6

Step 7

Turn layer: Viewport off. (Figure Step 7)

Figure Step 7

Step 8

Save and close the drawing.

AUTHOR’S CONSTRUCTION TECHNIQUES: The following steps are the construction technique suggested by the author to help you learn how to construct objects using AutoCAD. It is only the suggested method and if you can complete the drawing accurately using a different construction technique, that is what is important. You may want to compare your construction technique with the authors.
AUTHOR’S CONSTRUCTION HINTS: Do your best to complete the lab exercise drawing without using the following hints. If you get stuck and cannot complete it on your own, use the following hints to help you.

Hint 1

Once you have drawn the outer boundary and the inner construction lines (Step 3 above), use the OFFSET command to construct most of the remaining drawing.