To Redefine a Component as Ground
1. Right-click the component in the Model Tree and select 
from the shortcut menu. The Component Placement tab opens.
from the shortcut menu. The Component Placement tab opens.2. In the Placement tab, click the name of each Constraint Set, then right-click and choose Delete from the shortcut menu until all the constraint sets have been deleted.
3. Select User Defined from the list of predefined sets.
4. Select Default from the list of constraint types.
5. Click 
to accept the feature.
to accept the feature.6. On the ribbon, click the Mechanism tab. The component appears in the RIGID BODIES folder as Ground.
 | If you created your mechanism prior to Pro/ENGINEER 2001, ground body definitions may have been lost and may need to be redefined. |