Creating Datum on Non-Canonical Surfaces

You can create a datum on non-canonical surface (complex surface or prismatic surface) with the tolerancing advisor.

Before you begin: Open an existing 3D shape.
Related Topics
About Datum and Datum Target

  1. Click Tolerancing Advisor

    The Semantic Tolerancing Advisor dialog box appears.

  2. Multi-select the three spheres as shown:





    The Semantic Tolerancing Advisor dialog box is updated according to the selected surfaces.



    As you can notice, there is no Semantic Datum icon in the dialog box because it is not possible to create a datum on non-canonical surfaces, compare with Creating Semantic Datum and Datum Targets. To do this, you have to redefined the geometric surface to consider the non-canonical surfaces as an unique surface.

  3. Select One Surface in the Geometry feature type combo list in the Semantic Tolerancing Advisor dialog box.

    The Semantic Datum icon is now available.



  4. Click Semantic Datum icon (One surface):

    The Datum Definition dialog box appears.



    To define the unique surface representing the non-canonical surfaces, you have to select a plane which represents the orientation of this surface.

  5. Select the Plane direction field in the Datum Definition dialog box, and select the surface as shown on the Support component.



    The Plane direction field contains the representing surface:



  6. Click OK in the Datum Definition dialog box.

    The datum is created.

  7. Click Close in the Semantic Tolerancing Advisor dialog box.