Posted by Jake Atkinson on 05/10/2015 12:15:16:
It sounds mechanical, it has lots of grease and runs fine but just cant get rid of the noise plus when it is inside a guitar body the wood amplifies the sound.
The pickup slides perfectly fine with little effort but when i try and use a normal dc motor with no gears to slow it down it simply doesnt move.
I would expect the pickup be to very easy to move just using ones little finger. Lots of grease is not needed, and may well be a hinderance. Ideal would be a little light machine oil, say sewing machine oil.
Is it safe to assume that the pickup doesn't move anything except itself? How fast do you need it to move, and how accurate does placement have to be? Without knowing full details I would have thought that a stepper motor driving through a leadscrew should be fine. Stepper motors generate most torque at low speeds. While the stepper motor drive would be open loop I not sure if there is any need for a closed loop servo system?
The axes on my CNC mill are open loop stepper motor driven and they repeat to better than 0.01mm.
Andrew