Creating a Belt/Chain Assembly Feature

Use the Belt/Chain assembly feature to model systems of belts and pulleys or chains and sprockets.

The Belt/Chain assembly feature creates:
  • Belt mates to constrain the relative rotation of the pulley components.
  • A sketch containing a closed chain of arcs and lines describing the path of the belt.


The software calculates the length of the belt based on the positions of the pulleys. Optionally, specify the length of the belt and have the pulley positions adjust, at least one pulley must have an appropriate degree of freedom.

You can select to automatically create a part that contains the belt sketch and add the part to the assembly. In the part file, use the sketch as a sweep path to create a solid belt.

You can create belts using blocks in sketches.

To create a belt/chain assembly feature:

  1. Click Belt/Chain (Assembly toolbar) or Insert > Assembly Feature > Belt/Chain.
  2. Specify the PropertyManager options.
  3. Click .

    In the FeatureManager design tree, the following appear:

    • A Belt feature. The belt length appears next to the feature.
    • A BeltMates folder (under Mates ), containing mates between adjacent pulleys.
      To see the belt curve when the PropertyManager is closed, select the Belt feature in the FeatureManager design tree.
    If you selected Create belt part, a part containing the belt sketch is created and added to the Belt folder in the assembly. The part has:
    • An external reference to the assembly.
    • A LockToSketchMate that constrains the belt part to the belt sketch.
    • Custom properties Belt Length and Belt Thickness.

    If you selected Engage belt, you can drag to rotate one pulley to see all the pulleys rotate. Video: Assembly Belt Engaged

    If you did not select Engage belt, you can reposition one pulley without causing the others to rotate. Video: Assembly Belt Disengaged