I was trying to use a Rockwell Automation motor, the MPL-x310x-xJ72AA and after downloading and opening the file I noticed it was a surface only model...I couldn't add weight to it.
I was wondering if this is a 3D content Central issue or if its a problem with Rockwell Automation's model.
Here's a link to the part http://www.3dcontentcentral.com/secure/download-model.aspx?catalogid=3604&id=215553
This is what the part looks like in Solidworks
Its a "shell"
Any help or information would be greatly appreciated.