[Manoel]

Originally Posted by MikeDubreuil

I'm not particualrly mechanical but I'll give it a shot...

I'm going to call the pink piece that is supposed to move the output head. If you were to run a threaded piece of round stock through the tapped output head, and then turned the round stock the output head to move. A good choice of motor would be the globe motor to turn the round stock. If you added a rotation sensor to the round stock you could create some software to fairly acurately shift the transmission for you.

Yeah, that's exactly what I was talking about...
Yay for non-mechanicals chiming in...