Clamping leadscrew coupler

I have been having trouble getting a good coupler design working on the Z axis of a new printer I'm working on. This was the final result. It couples a 5mm motor shaft with a 10mm lead screw. If you need another size, let me know, and I'll make it. Also, I can share whatever format OnShape exports.

It's basically a collet with two clamps. Three screws clamp it down, and it works very well so far. Self-centering, strong, clamps really well.

**Update 14 March 2016**: Uploaded collet for 5mm motor to 8mm leadscrew, and .step files for collet and clamps. The same clamps will work fine.