An OpenSCAD module (STL also included) for a Canon EF-M lens mount (the lens side). My initial use for this was to make an adapter to connect my Canon EOS-M camera to a telescope. Hopefully this module is useful to others that want to make custom EF-M adapters.
The design has a recess for the lock pin so it should bayonet and lock like a normal lens. The bayonet fins are tapered slightly for a better fit on the camera and should allow printing without any clean-up. There's also a channel for the electrical contacts so that the mount doesn't push them in too far - I had issues in earlier designs with a pin getting stuck in the pushed-in state. The camera-side of the mount includes a small alignment dot, but I would probably add a more visible dot to whatever is added to the mount.
I was inspired by http://www.thingiverse.com/thing:10829, an EF lens mount, but did not directly use any of the design because EF-M is fairly different. The partial rotate extrude code from http://www.thingiverse.com/thing:34027 was extremely handy since it allowed me to easily make the more complex tapered bayonet fins.