Creating Angular Dimensions

This task shows you how to create angular dimension annotations.

• When the dimension supports are related to a parameter (sketch's constraints, knowledge, etc) for which tolerances are still defined, they are set to the dimension tolerances.

1. Click Dimensions  in Annotations toolbar.

2. Select the surfaces as shown on the part.

   A linear dimension appears during the creation process before you select the second surface.

   The angular dimension appears. If the angular dimension does not appear, right-click the dimension and from the contextual menu select Angle.

3. Right-click the angular dimension and select Angle Sector > Sector 4 from the contextual menu. 

   The angular dimension is modified.

4. Click outside any geometry to end the dimension creation process.

5. Right-click the angular dimension and select Dimension.1 object > Angle Sector > Sector 1 from the contextual menu.

   The angular dimension sector is modified.

If the Always try to create semantic tolerances and dimensions option and the Always try to create semantic general tolerances on dimensions option have been selected, the dimension is set as semantic. The Toleranced Angular Size icon is displayed in the specification tree and the angular dimension named Angular Size.1 during the dimension creation process.

6. Select the two surfaces as shown, to create semantic angular dimension.
7. Click Tolerancing Advisor in Annotations toolbar.
   The Semantic Tolerancing Advisor dialog box appears.
   The buttons and options available in the dialog box depend on your selection.

   The Propagation Selection options are displayed according to the type of face selected depending on the canonicity. In this scenario the options are not used. For more information, refer to Propagating Geometry Selection for Feature Creation.

8. Click Angle Creation . The Limit of Size Definition dialog box appears.

   The angular dimension is previewed and the Limit of Size Definition dialog box appears, offering the following options: General Tolerance: Lets you define a pre-defined class of tolerance; see Tolerances for the default class setting.   From R18 onwards, the standards for general tolerance, ISO 2768-1 (1989) and ANSI B4.3 – 1978 are supported for angular dimensions. If the semantic standard ISO is used, then the Standard field in the Limit of Size Definition dialog box allows you to choose between ISO 2768-f or ISO 2768-m or ISO 2768-c or ISO 2768-v. If the semantic standard ASME is used, then the Standard field will give only one option of ANSI B4.3-1978. According to ISO and ASME standards, only the nominal value of the dimension is displayed in 3D. The tolerance values are not displayed. The numerical values of the general tolerance can be seen without editing the dimension through the tooltip text. The angular general tolerance values are displayed through a tooltip in a yellow text box, when the mouse is moved over the dimension, both in the specification tree and in the 3D. The general tolerance values will always be displayed in degrees/minutes/seconds in the tool tip. The values in millimeters per 100mm and in milliradians as described in the ANSI B4.3-1978 standard are not supported. The general tolerance values of angular dimensions are based on the shortest length of the two legs forming the angle. Depending on this shortest length, the tolerance values have been defined for the standards (ISO, ANSI). In this case three angular dimensions are created with different leg lengths. You can see that for the same angular value, the tolerance value changes depending on the shortest leg length. The following cases of semantic angle dimensions are supported: angle of a conical face, angle between two non parallel planar faces, angle between a cylindrical and a planar face that not parallel and angle between two cylindrical faces. Numerical values: Lets you define the Upper Limit and optionally the Lower Limit (provided you clear the Symmetric Lower Limit option). Single limit: Lets you enter a minimum or maximum tolerance value. Use the Delta / nominal field to enter a value in relation to the nominal value. Information: Lets you to set the dimension as information (ISO-based standards)/ reference (ASME-based standards). The information/reference dimension is displayed enclosed by parentheses in geometry window.

9. Click OK. The angle is created.
10. Click Close in the Semantic Tolerancing Advisor dialog box.
11. The numerical description of the angle can be changed using the Numerical Properties toolbar.

    In this case change the Numerical Display Description to NUM.ARAD and Precision to 0.00100.

    The dimension is updated.

12. To edit the semantic angular dimension, right-click it and select Angular Size.1 object > Definition....
    The Limit of Size Definition dialog box appears.
    You will see that in the Numerical values, Upper Limit and Lower Limit, the unit has been changed from min to rad even if the knowledge unit is still Degree, Minute, Second (Tools > Options > General > Parameters and Measures, Units tab).

    From R18 onwards, the contextual menus Add Multiple Values and Add Range are not supported, in the Limit of Size Definition dialog box, Numerical values, Upper Limit and Lower Limit fields.

13. Change the Upper Limit to 0.005rad.
14. Click OK.
    The dimension is updated.