I'd thought of some kind of feed forward controller, this could work, don't know if a software FIR filter would completely solve the problems, it would be really bad for prints to have any overshoot, especially on square corners. In my intial firmware tests I was getting about 50KSamples/s on both channels so should be enough to do stuff like this. I suppose if you were being crazy mental you could interleave every valid point with the laser on with an off point at one of the extents.....hmmm!

The hysteresis fades to almost nothing with the damping system removed, unfortunately then any external vibrations cause significant wobblies and with the current drive system (when the audio buffer underruns) it is unuseable without the damping....a step reponse in drive leads to significant oscillation. I will try adding a LPF to my driver and remove the damping to see what I get.

Adding DC position feedback would be relatively trivial electronics but the mechanicals are probably going to be too precise to get decent results, also adding weight to the rotor....at that stage there's probably an argument for rigid bearings and more drive....then we've made some proper galvos......we should make these....http://elm-chan.org/works/vlp/report_e.html