Multibody Parts Versus Assemblies

Multibody parts should not replace the use of assemblies.

A general rule to follow is that one part (multibody or not) should represent one part number in a Bill of Materials. A multibody part consists of multiple solid bodies that are not dynamic. If you need to represent dynamic motion among bodies, use an assembly. Tools such as Move Component, Dynamic Clearance, and Collision Detection are available only with assembly documents.

Saving an Assembly as a Multibody Part

You can save an assembly as a multibody part document.

Saving complex assemblies as smaller part documents can be useful in various situations.
  • Makes sharing files easier. For example, you have a design of an intricate motor assembly and a potential customer wants to know if it fits in their frame. You can save the motor assembly as a part document and send the part file to potential customers without risking design integrity or transmitting a large assembly document file.
  • Simplifies large assemblies. For example, you can use the multibody part as a simplified representation of the assembly in a higher layout assembly.

To save an assembly as a multibody part document:

  1. Open an assembly document.
  2. Click File > Save As.
  3. Optional: 3DEXPERIENCE Users: If the Save As New dialog box appears, click Save to This PC.
  4. Set the Save as type to Part (*.PRT, *.SLDPRT).
    A set of options appears at the bottom of the dialog box.
  5. Select one of the following:
    • All Components to save all components as Solid Bodies .
      Components that are hidden or suppressed are not saved when you select All Components.
    • Exterior Faces to save the exterior faces as Surface Bodies .
    • Include specified components to save the visible components as Solid Bodies .
  6. Select or clear the following:
    • Preserve geometry references. Saves data for the assembly mates in the multibody part. This is useful when you use the multibody part as a simplified representation of the assembly in a higher layout assembly and then make changes later. When you change the subassembly and then save the subassembly again as a multibody part, you can replace the previous multibody part with the new multibody part, without having to recreate the mates.

      See Replacing Subassemblies with Multibody Parts.

  7. Click Save.