Hello,
The Multimedia team at the Wikimedia Foundation is working to enable Commons support for 3D objects in the .STL file format. 

https://phabricator.wikimedia.org/T3790

While the technical work is well underway the Legal team at the foundation recently shared some points addressing 3D files from a legal perspective. Particularly concerns around patented objects and objects that are weapons.

https://meta.wikimedia.org/wiki/Wikilegal/3D_files_and_3D_printing

I encourage Commonists interested in discussing the details of this feature to participate in a discussion in preparation for the feature. I have shared this on the Commons Village Pump if you would like to discuss further. 

https://commons.wikimedia.org/wiki/Commons:Village_pump#Wikilegal_post_on_3D_files_and_3D_printing

Yours,
Chris Koerner
Community Liaison
Wikimedia Foundation