Learning AutoCAD 2010, Volume 2 phần 4 potx

104 ■ Chapter 8: Dimensioning Dimensions for Linear Objects Guidelines ■ Always use Object Snaps to select the dimension origin points. ■ Depending on the geometry you are dimensioning you may select objects to dimension rather than specifying the endpoints. ■ A Linear dimension will be horizontal or vertical depending on the direction you drag the dimension line from the object. ■ An Angular dimension may be located inside or outside the angle depending on where you drag the arc line location. ■ To ensure that Continuous and Baseline dimensions build correctly, create the base Linear, Aligned or, Angular dimension choosing the first and second origin points accordingly. Baseline dimensions are built from the first origin point. Continuous dimensions are built from the second origin point. ■ When you select the base dimension for your Continuous or Baseline dimensions, select the dimension towards the side that you want the continued or baseline dimension to reference. ■ Adjust the location of the dimension using Grips when necessary. ■ If the origin point you selected is incorrect, zoom in closer to the object and use the grips to relocate the origin point to the object. The Dimlinear and Dimaligned commands prompt you for two points or to select an object. Press ENTER to select the object to dimension. This is often quicker than selecting two points. Lesson: Creating Dimensions ■ 105 Creating Dimensions on Curved Objects Using commands to place dimensions on curved objects in the drawing is a straightforward process. Pay attention to the command prompts as they guide you through the required selections. These dimensions can be selected from the list on the Dimensions panel. The following illustration shows a variety of dimensions for curved objects. 106 ■ Chapter 8: Dimensioning Procedure: Creating an Arc Length Dimension Use the following command to dimension the length of an arc. Command Line: DIMARC Ribbon: Annotate tab > Dimensions panel > Arc Length The following steps give an overview of creating an arc length dimension: 1. Start the Dimarc dimension command. 2. Select an arc (1). 3. Click to position the arc length dimension (2). Lesson: Creating Dimensions ■ 107 Practice Exercise: Arc Length Dimensions In this practice exercise, you draw several arcs, then use the Arc Length command to dimension the arcs. 1. To create Arc Length dimensions on the arcs you have drawn: ■ Begin the Arc Length command. ■ Select the arc (1). ■ Specify the arc length dimension location (2). 2. Repeat the Arc Length command to dimension the remaining arcs. Note: The arc length symbol can precede the dimension text, be above the dimension text, or be turned off. This symbol can be controlled using the DIMSTYLE command. Select: Modify > Symbols and Arrows > Arc Length Symbol. 108 ■ Chapter 8: Dimensioning Procedure: Creating a Radius Dimension Use the following command to dimension the radius of a circle or arc. Command Line: DIMRADIUS, DIMRAD, DRA Ribbon: Annotate tab > Dimensions panel > Radius The following steps give an overview of creating a radius dimension: 1. Start the Dimradius command. 2. Select an arc or circle (1). 3. Click to position the dimension (2). Lesson: Creating Dimensions ■ 109 Practice Exercise: Radius Dimensions In this practice exercise you use the Radius Dimension command; first, create a drawing that resembles the object shown below. Note: To ensure a manageably sized drawing, begin with a blank drawing based on the acad.dwg template. 1. To create the object to dimension: ■ Draw a rectangle. ■ Begin the Fillet command and set the fillet radius to .25 or .5. ■ Use the Polyline option of the Fillet command to fillet all 4 corners of the rectangle. Note: A rectangle is a polyline meaning all the lines are connected and recognized as a single object. ■ Begin the Offset command. ■ Specify an offset distance of .15. ■ Offset the polyline. 2. To dimension the outside fillet: ■ Begin the Radius command. ■ Select the arc (1). ■ Specify the dimension line location (2). 3. Repeat the command to dimension the inside radius (3). 110 ■ Chapter 8: Dimensioning Procedure: Creating a Jogged Radius Dimension Use the following command to dimension a radius where you want to override the center origin point of the dimension to another location. This will create a jogged radial dimension. Command Line: DIMJOGGED Ribbon: Annotate tab > Dimensions panel > Jogged The following steps give an overview of creating a jogged radius dimension: 1. Start the Dimjogged command. 2. Select an arc or circle (1). 3. Specify a center location override (2). 4. Specify a dimension line location (3). 5. Specify the jog location (4). Lesson: Creating Dimensions ■ 111 112 ■ Chapter 8: Dimensioning Practice Exercise: Jogged Radius Dimensions In this practice exercise you draw an arc and use the Jogged radius dimension command. 1. Draw an arc. 2. To create a jogged radius: ■ Enter DIMJOGGED and press ENTER. ■ Select the arc (1). ■ Specify the center point location override (2). ■ Specify the dimension line location (3). ■ Specify the jog location. Lesson: Creating Dimensions ■ 113 Procedure: Creating a Diameter Dimension Use the following command to dimension the diameter of a circle or arc: Command Line: DIMDIAMETER, DIMDIA Ribbon: Annotate tab > Dimensions panel > Baseline The following steps give an overview of creating a diameter dimension: 1. Start the Dimdiameter command. 2. Select an arc or circle (1). 3. Click to position the dimension (2). [...]... Select the line at point (2) s Position the dimension as shown 10 To create a linear dimension: s On the Dimensions panel, click Linear s Select point (1) s Select point (2) s Position the dimension as shown 130 s Chapter 8: Dimensioning 12 To create a linear dimension: s On the Dimensions panel, click Linear s Select point (1) s Select point (2) s Position the dimension as shown  14 To clean up the overlapping... point (2) s Specify the dimension line location at point (3) s Specify the jog location at point (4) 8 To create a diameter dimension: s On the Dimensions panel, click Diameter s Select the circle indicated (1) and position the dimension as shown (2) The dimensions are equally spaced 5 To create an aligned dimension: s On the Dimensions panel, click Aligned s Select point (1) as shown s Select point (2) ... panel > Break The following steps give an overview for breaking dimensions: 1 Start the Dimbreak command Lesson: Creating Dimensions s 121 2 Select the dimension to break (1) Note: Use the Multiple option to break multiple dimensions 3 Select objects to break the dimension (2) and press ENTER Note: Simply press ENTER to break the dimension automatically wherever it intersects with other objects or dimensions... DIMJOGLINE Ribbon: Annotate tab > Dimensions panel > Jog Line The following steps give an overview for adding a Jog Line to a dimension: 122 s Chapter 8: Dimensioning 1 Create a linear dimension between two points and enter the text override value to represent the stated value 2 Start the Dimjogline command and select a linear dimension 3 Click a point on the dimension to place the jog line symbol Removing... the geometry changes size, the dimension updates accordingly 1 24 s Chapter 8: Dimensioning Procedure: Adding Tolerances Use the following command to add a dimension Tolerance to your drawing: Command Line: TOLERANCE, TOL Ribbon: Annotate tab > Dimensions panel > Tolerance The following steps give an overview of adding a dimension Tolerance: 1 2 Start the Tolerance command From the Geometric Tolerance... Tolerance in the drawing Lesson: Creating Dimensions s 125 Procedure: Inspecting Dimensions Use the following command to add an inspection label to a selected dimension: Command Line: DIMINSPECT Ribbon: Annotate tab > Dimensions panel > Inspect The following steps give an overview of creating an inspection label 126 s Chapter 8: Dimensioning 1 2 Start the Diminspect command From the Inspection Dimension... Diameter Dimensions In this practice exercise you draw several circles and use the Diameter dimension command 1 1 14 To dimension the diameter of a circle: s Begin the Diameter dimension command s Select the circle (1) s Specify the dimension line location (2) s Chapter 8: Dimensioning 2 Repeat the Diameter command to dimension the remaining circles Procedure: Creating Center Marks Use the following... available in AutoCAD LT® Warning! Procedure: Ordinate Dimensions Use the following command to create Ordinate dimensions Command Line: DIMORDINATE, DIMORD Ribbon: Annotate tab > Dimensions panel > Ordinate The following steps give an overview of creating Ordinate Dimensions To dimension using Ordinate Dimensions, you must first change the Origin point Lesson: Creating Dimensions s 119 1 2 3 120 Enter UCS... Select the left end extension line 1 and 2 as shown s Right-click Click Break The selected extension lines break whenever they cross another extension line 13 To create baseline dimensions: s On the Dimension toolbar, click Baseline s The last dimension created is automatically used as the base dimension s Select point (1), point (2) , point (3), and point (4) in order s Press ENTER to complete the... command Lesson: Creating Dimensions s 117 2 Select the geometry to dimension using standard selection methods 3 By default, a series of continuous dimensions is previewed Right-click anywhere in the drawing to change the dimension types or options Available options are: Continuous, Staggered, Baseline, Ordinate, Radius, Diameter, Datumpoint, Edit, and Settings 4 Click to position the dimensions The dimensions . command. 2. Select an arc or circle (1). 3. Specify a center location override (2) . 4. Specify a dimension line location (3). 5. Specify the jog location (4) . Lesson:. 2. Start the Dimordinate command. 3. Use object snap to specify the feature location (2) , then specify the leader endpoint (3). Lesson: Creating Dimensions ■ 121 4. . dimension: 1. Start the Dimdiameter command. 2. Select an arc or circle (1). 3. Click to position the dimension (2) . 1 14 ■ Chapter 8: Dimensioning Practice Exercise: