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

AutoCAD’s Menu Systems

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

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

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

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

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

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

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

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

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

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.

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

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.

Step 21

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

Figure Step 21

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

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

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

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

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

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

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

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.

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

Step 3

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

Figure Step 3

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

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

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

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

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

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.

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

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

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

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

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

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

Step 18

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

Figure Step 18

Key Principles

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:

• A Using the NEW command, start a new drawing using the template: 2D Metric
• B Save and name the drawing with the name: AutoCAD 2D Lab 02-2
• C Save the drawing in the folder:

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

• D Using the CLOSE command, close the

Step 8

Complete the following:

• A Using the OPEN command, open the drawing: AutoCAD 2D Lab 02-2
• B Using the SAVEAS command, save and name the drawing: AutoCAD 2D Lab 02-3
• D Using the CLOSE command, close the drawing.

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

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

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

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

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

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

Step 11

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

Figure Step 11

Step 12

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

Figure Step 12

Step 13

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

Figure Step 13

Step 14

Save and close the drawing.

Key Principles

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 ‘.

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:

Step 4

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

Figure Step 4

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

Step 5

Save and close the drawing.

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.

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

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

Step 5

Save and close the drawing.

Key Principles

Lab Exercise 4-1

Time allowed: 30 minutes.

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

Step 5

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

Figure Step 5

Step 6

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

Figure Step 6

Step 7

Save and close the drawing.

Hint 1

See Figure Hint 1.

Figure Hint 1

Lab Exercise 4-2

Time allowed: 30 minutes.

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

Step 6

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

Figure Step 6

Hint 1

See Figure Hint 1.

Figure Hint 1

Lab Exercise 4-3

Time allowed: 30 minutes.

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.

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

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

Step 4

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

Figure Step 4

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

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

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.

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.

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

Key Principles

Lab Exercise 5-1

Time allowed: 30 minutes.

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

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

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

Figure Step 7

Step 8

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

Figure Step 8A

Figure Step 8B

Step 9

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

Figure Step 9A

Figure Step 9B

Hint 1

Figure Hint 2

Lab Exercise 5-2

Time allowed: 40 minutes.

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

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

Step 8

Save and close the drawing.

Hint 1

Figure Step Hint 1

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:

• Without the aid of an instructor, complete the written test and the lab exercise.
• In a classroom with an instructor, the instructor will give instructions on what to do after this module has been completed.

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

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

Step 5

Save and close the drawing.

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

Draw Toolbar

Draw Pull-down

Home Ribbon

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

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

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

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

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.

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

Lab Exercise 7-1

Time allowed: 40 minutes.

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.

Hint 1

(Figure Hint 1)

Figure Hint 1

Lab Exercise 7-2

Time allowed: 40 minutes.

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.

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:

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

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

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

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

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

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

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

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

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

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.

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

Lab Exercise 8-1

Time allowed: 30 minutes.

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.

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.

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.

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.

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.

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.

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.

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

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

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

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

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:

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

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

Step 14

Save and close the drawing.

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

Key Principles

Lab Exercise 9-1

Time allowed: 40 minutes.

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

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.

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.

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

Figure Step 2B
Completed Drawing

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.

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

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

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

Object A Solution:

Step 2

Study the figure and find the solutions for numbers 1 to 11. (Figure Step 3)

Figure Step 2

Object B Solution:

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

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

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

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

Lab Exercise 10-1

Time allowed: 30 minutes.

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.

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.

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.

Hint 1

See the figure for the polar coordinates. (Figure Hint 1)

Figure Hint 1

Lab Exercise 10-3

Time allowed: 40 minutes.

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.

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:

Object B Solution:

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:

• Without the Aid of an Instructor, complete the written test and the lab exercise.
• In a Classroom with an Instructor, the instructor will give instructions on what to do after this module has been completed.

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

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

Figure Step 2B

Step 3

Draw all construction objects on layer: Construction.

Step 4

When complete, freeze layer: Construction.

Step 5

Save and close the drawing.

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

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

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

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

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

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

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

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

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:

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

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

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

Lab Exercise 12-1

Time allowed: 30 minutes.

Step 1

Draw the object shown in the figures using the layering scheme. (Figure Step 1A and 1B)

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

Save and close the drawing.

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.

Step 1

Draw the object shown in the dimensioned drawing using the layering scheme. (Figure Step 1A and 1B)

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

Save and close the drawing.

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

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

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

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

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

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

Step 18

Select the bottom circle. In the Properties window, change the Linetype scale property to 1.500. (Figure Step 18)

Figure Step 18

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:

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

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)

Figure Step 4A

Figure Step 4B

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

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

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

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

Key Principles

Lab Exercise 13-1

Time allowed: 30 minutes.

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

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

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.

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

Lab Exercise 13-3

Time allowed: 30 minutes.

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A

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

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.

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

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.

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

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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

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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

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:

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

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)

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

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

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.

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

Lab Exercise 14-1

Time allowed: 40 minutes.

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

Figure Step 1A

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.

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.

Step 1

Draw the object shown in the figure using the layering scheme. (Figure Step 1A and 1B)

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

Save and close the drawing.

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.

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.

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

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AutoCAD Command: ID

The ID command is used to return the coordinate location for a point in Model or Paper space.

Shortcut: none

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Figure 15-1
Object Snap Mode – Perpendicular

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.

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

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:

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>: 1 

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

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

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

Figure Step 12B

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

Lab Exercise 15-1

Time allowed: 40 minutes.