- Chapter Objectives
- 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
Dimensioning
AutoCAD’s dimensioning tools can automatically measure distances and place dimensions on your drawing. You can simply select objects and let AutoCAD add the appropriate dimensions, or you can tell AutoCAD what type of dimension you want to place and what object or points you wish to dimension. You can access the dimension tools from the Dimensions panel on the Annotate tab of the ribbon shown earlier in Figure 2-29.
EXERCISE 2-17 PLACING DIMENSIONS
1 Select the Annotate tab of the ribbon to switch to the annotation tools.
2 Select the Dim Layer Override drop-down list on the Dimensions panel and set the Dim layer current.
3 Choose the Dimension tool from the Dimensions panel to start the DIM command. AutoCAD prompts you to Specify objects or specify first extension line origin or ↓.
4 Pick the line at the bottom of the drawing (point 1 in Figure 2-37). AutoCAD starts dragging a dimension from that line and prompts you to Specify dimension line location or second line for angle ↓.
Figure 2-37 Adding dimensions
5 Pick a point below the line. The dimension is placed, and AutoCAD prompts you to Select objects or specify first extension line origin or ↓.
6 Pick the line at the right side of the drawing (point 2 in Figure 2-37).
7 Drag the dimension to the right and pick a point to place it. The dimension is placed, and AutoCAD prompts you to Select objects or specify first extension line origin or ↓.
8 Select the circle and pick a point above and to the left of the circle (point 3 in Figure 2-37). The dimension is placed, and AutoCAD prompts you to Select objects or specify first extension line origin or ↓.
9 Press the down arrow and choose the Baseline option from the menu. AutoCAD prompts you to Specify first extension line origin as baseline or ↓.
10 Pick the left dimension line of the first dimension you created (point 1 in Figure 2-38). A dimension line rubber-bands from the dimension you selected.
Figure 2-38 Adding baseline dimensions
11 Make sure your Object Snap toggle is turned on in the status bar and move your cursor near point 2 shown in Figure 2-38. When the Endpoint object snap appears, pick that point to select the endpoint of that line. AutoCAD will place the dimension and start dragging a new dimension.
12 AutoCAD prompts you to Specify a second extension line origin or ↓. Press the down arrow and choose the Select option from the menu. AutoCAD prompts you to Specify first extension line origin as baseline or ↓.
13 Pick the upper dimension line of the vertical dimension (point 3 in Figure 2-38).
14 Move your cursor near point 4 shown in Figure 2-38. When the Endpoint object snap appears, pick that point to select the endpoint of that line. AutoCAD will place the dimension and start dragging a new dimension.
15 Press <Esc> twice to end the DIM command.
16 Save your drawing.
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You now have some basic dimensions on your drawing. The look and orientation of the dimensions are controlled by the dimension style.
One of the unique aspects of dimensions is their ability to update automatically as the drawing changes. This feature is called associativity, which means that dimensions are associated with the geometry and will automatically update when the geometry changes. In the next section, we’ll look at some ways to modify your drawing and see how the associative dimensions follow along.
associativity: A link between drawing objects and dimension objects. Associative dimensions will update and follow the drawing objects to which they are linked.