Assembly Design > Top Down Design > Skeleton Models > About Creating Geometry for a Motion Skeleton Model
  
About Creating Geometry for a Motion Skeleton Model
Before creating a design skeleton for a motion skeleton, you must create geometry references. Use the Datum Coordinate System tool to create a coordinate system and the Datum Plane tool to create datum planes for the motion skeleton.
Enter Sketcher to design your mechanism by sketching entities that will create the geometry. When you exit Sketcher, the sketched entities become separate curve entities. These curves are used as the body skeletons that define the body structure of the mechanism.
You must select entities from the design skeleton to create a body skeleton. The entities selected must be sufficient to define a Mechanism body. The body skeleton geometry is therefore, an External Copied Geometry feature of the design skeleton. Bodies so created are placed in relation to one another with predefined sets. A predefined constraint set (pin, slider, cylinder, ball, bearing) is automatically defined based on the selected geometry and sketching assumptions. Motion axes are automatically created. Other predefined constraint sets can be manually configured on the Component Placement tab.