You could add limit mates, which would allow the saddle and table to move, but only within a specified range. However, limit mates can slow performance significantly, so they should be used only when necessary (for example, for collision detection). Instead, add mates to lock the saddle and table in position, to prevent unexpected movement of these components as you add more components.
First, mate the right plane of the saddle to the right plane of the table.
If an item was already selected
in the graphics area, it appears under Mate
Selections. Right-click in the selection box and click Clear
Selections.
In the flyout FeatureManager design tree:
Expand saddle and table.
Select the following for Entities
to Mate
:
Right Plane of saddle
Right Plane of table

Accept the Coincident
mate.