That sounds awesome Pete!

As for the hysteresis/memory issues, maybe it can be tuned for in software? Hysteresis usually is predictable, so I'm thinking it would just need to calculate an overshoot based on the anticipated deflection angle of the laser.

Kindof like backlash compensation on CNC systems.

The peachy team would need to get a test setup to collect data on memory vs deflection angle, and then generate a lookup table based on

1) the angle of the axis,

2) the direction that axis is presently moving.

3) the present speed of the axis.

4) the future direction of the axis (acceleration or deceleration)

This is all rather challenging, and I personally would have great difficulty implementing it. Officially it would be called feed forward hysteresis compensation.

I wonder if there is any way to provide inexpensive closed loop feedback from the moving mirrors, because in that case you could get accurate positioning with a basic PID controller.

I do remember that there are magnets on the mirrors... maybe a hall sensor could detect some positioning info? Or maybe if the magnet is moving quickly, a sense coil could get the EMF, send that EMF voltage wave back to the controller, then integrated the wave to provide the positional data (plus a constant) of the system based on Faraday's Law.

Important to note, that this EMF value can be considered as the "I" in the PID.... it may be possible to get a "P" or proportional feedback in some other way.

These are just ideas, so please correct me if Im wrong in any part.