I am planning out a rapid prototyping machine based on a 3 axis machine of old printers. I think I can do this part well enough - there is a ton of info on the internet. A mill is similar, but that ...

Divide and conquer. That's exactly what engineers at Medtronic Sofamor Danek did when they prototyped the company's latest surgical tool, a counter-torque ratchet that drives in spinal implant screws ...