- Introduction
- Creating a New Drawing
- Model Space and Layout Space
- Communicating with AutoCAD
- Object Snaps, Ortho Mode, and Polar Tracking
- Undo/Redo
- Grid and Snap
- Draw a Circle
- Navigating Around the Drawing
- Object Properties
- Layers
- Dimension Styles
- Dimensioning
- Modifying Drawing Objects
- Grip Editing
- Introduction to Advanced Editing Techniques
- Cleaning Up Layout Space
- Plotting and Page Setups
- Chapter Summary
- Chapter Test Questions
This chapter is from the book
This chapter is from the book
This chapter is from the book
Introduction to Advanced Editing Techniques
A few of the advanced editing techniques are indispensable in AutoCAD. In fact, these commands and techniques are used extensively when creating AutoCAD drawings, which may seem counterintuitive. Using CAD, it is not uncommon to create a drawing by drawing more than you need and then editing and refining information to make the final product. This section introduces you to a few of these techniques.
Making Parallel Copies
Sometimes it is necessary to make an exact copy of a line or circle that is a specific distance from the original. This is referred to as an offset in AutoCAD. It is possible to offset a specific distance or even through a point that you specify while maintaining a copy of the original object. It is even possible to make multiple copies.
EXERCISE 2-22 OFFSETTING OBJECTS
Choose the Offset tool from the Modify panel. AutoCAD prompts you to Specify offset distance or 
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Type .125<Enter>. AutoCAD prompts you to Select object to offset or .
Pick the horizontal line at the top of the drawing (point 1 in Figure 2-47). AutoCAD prompts you to Specify point on side to offset or .
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FIGURE 2-47 Offsetting lines
Pick a point below that line (point 2 in Figure 2-47). AutoCAD places a copy of the line .125″ below the original. AutoCAD prompts you again to Select object to offset or .
Pick the next horizontal line down from the top of the drawing (point 3 in Figure 2-47). AutoCAD prompts you to Specify point on side to offset or .
Pick a point above that line (point 4 in Figure 2-47). AutoCAD places a copy of the line .125″ above the original. AutoCAD prompts you again to Select object to offset or .
Pick the vertical line on the left side of the drawing (point 5 in Figure 2-47). AutoCAD prompts you to Specify point on side to offset or .
Pick a point to the right of that line (point 6 in Figure 2-47). AutoCAD places a copy of the line .125″ to the right of the original and prompts you again to Select object to offset or .
Pick the next vertical line to the right of the drawing (point 7 in Figure 2-47). AutoCAD prompts you to Specify point on side to offset or .
Pick a point to the left of that line (point 8 in Figure 2-47). AutoCAD places a copy of the line .125″ to the left of the original and prompts you again to Select object to offset or .
Save your drawing.
Fixing Overlapping Lines and Closing Gaps
Often it is necessary to “clean up” lines that overlap and/or do not meet exactly so that there is a gap. Remember that the key to using AutoCAD effectively is to draw everything as precisely as possible. There is no room for even the tiniest overlap or gap. These small errors can propagate larger errors when dimensions are added or parts are mated together. AutoCAD provides a number of methods for cleaning up your drawings quickly.
EXERCISE 2-23 TRIMMING AND EXTENDING OBJECTS
Choose the Trim tool from the Modify panel. The current command settings are displayed at the command line, and AutoCAD prompts you:
Current settings: Projection=UCS, Edge=None Select cutting edges... Select objects or <select all>:
Select lines 1–4 shown in Figure 2-48 and press <Enter>. AutoCAD prompts you to Select object to trim or shift-select to extend or .
Pick a point on the short line segment shown at point 1 in Figure 2-48. The vertical line is trimmed, and AutoCAD prompts you again to Select object to trim or shift-select to extend or .
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FIGURE 2-48 Trimming and extending lines
Pick the line segments shown at points 2, 3, and 4 in Figure 2-48. The lines are trimmed.
Press <Enter> to exit the Trim tool. Notice that the dimensions automatically update to reflect the new sizes.
Choose the Extend tool from the Modify panel. The current command settings are displayed at the command line, and AutoCAD prompts you:
Current settings: Projection=UCS, Edge=None Select boundary edges... Select objects or <select all>:
Select lines 3 and 4 in Figure 2-48 and press <Enter>. AutoCAD prompts you to Select object to extend or shift-select to trim or .
Press the down arrow on your keyboard or type E<Enter> and select the Extend option.
Pick a point toward the top of line 3 in Figure 2-48. The vertical line is extended, and AutoCAD prompts you again to Select object to extend or shift-select to trim or .
Pick a point on the left of line 4 in Figure 2-48. The line is extended.
Press <Enter> to exit the Extend tool.
Choose the Fillet tool from the Modify panel. The current command settings are displayed at the command line, and AutoCAD prompts you:
Current settings: Mode = TRIM, Radius = 0.0000 Select first object or
Select lines 1 and 2 near the upper-left corner in Figure 2-48. Both lines are trimmed to form a closed corner by creating a fillet with a radius of 0.00.
Choose the Erase tool from the Modify panel and erase lines 5, 6, 7, and 8 (see Figure 2-48).
Your drawing should now look like Figure 2-49. Use grips to select the dimension extension line origin as shown and attach it back to the corner of the drawing using an Endpoint object snap. Make sure the Object Snap button is on.
Save your drawing.
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FIGURE 2-49 The updated drawing