Summary I've seen these motors on sciplus for years now, and just recently saw them on amazon. Since their popularity means other people might be using them, here is a model that makes mine much more useful. Included is a picture of the kind of motor I designed this for. Instead of using the outer edges of the threads as a shaft, or paying almost a thousand dollars for a tap set for 7/16 ACME threads, clamp these to either side of the screw shaft and drive something with 40mm hex. Needs 6 m4 nuts and 6 30mm m4 screws. New version includes provision for an M3 setscrew(optional). will require two m3 nuts and two m3 setscrews. There is a gear on the shaft for driving a rotary encoder. Also included a gear for the encoder. For the curious, I use this to drive gears like the big one included in this thing.