What to Do When the First Feature Is the First Component

Assemblies that are created without any initial features, such as default datum planes, pose a problem if you want to rework them—for example, get features in before the first component, replace the first component, or reorder a component so that it’s before the first component. You can work around this by temporarily adding a skeleton model.

Retrieve the assembly in Pro/ENGINEER®, and then follow these steps.

1. Create a skeleton model. Starting from the Assembly menu, select Component, Create, Skeleton Model. Accept default name, OK. Under the Create Options dialog box, select Empty, OK.

2. Position assembly insert mode after skeleton. From the Component menu, select Insert Mode, Activate. Then select the skeleton from the model tree.

3. Create assembly datums. Create three default assembly planes by selecting the Create datum plane icon. The three datum planes will appear. Create a default coordinate system by selecting the Create coordinate system icon, Default, Done.

4. Cancel insert mode. From the Component menu, select Insert Mode, Cancel, and answer Yes to the prompt to resume.

5. Redefine first component constraints to reference created assembly datum features. From the Component menu, select Redefine. Pick the first component in the assembly, remove the default constraint, and add the new constraint using either the newly created assembly datum planes or coordinate system.

6. Delete the skeleton model.

7. Save and celebrate!

Claes Albertson is an application specialist at Tetra Pak ComTec AB in Lund, Sweden. He can be reached by email at claes.albertson@tetrapak.com.