Hello...
I'm using Mach 3 with a HobbyCNC 3-axis board, and I'm having trouble with arbitrary loss of steps...
This has happened several times now, usually on the Y or X axes... For instance, today I was milling polystyrene foam wings, at ~150 IPM... Light cuts, 0.005" per pass... I had cut a pair of wing beds and a wing, no problem... I go to cut the other wing, and it was about 50% finished when the X-axis suddenly lost ~1", and destroyed the part. I canceled the job, and returned the axes to home, and sure enough, the home point had moved by ~1" in the X-direction.
I checked the mechanical systems (it's a DIY mill, so sometimes things slip), but everything was in order. I was sitting right there, watching it run, so I know that it didn't stall on anything, either. Also, at 150 IPM, the steppers aren't being pushed too hard, the machine can jog (or rough-cut foam) at 350 IPM without skipping.
Any suggestions, at least as to where I should start trouble-shooting? Could this be caused by a dirty power supply? For what it's worth, I'm running a shopvac and the 'spindle' (a Hitachi router) off the same circuit as the computer and stepper controller, and I've been meaning to get a surge protector for about two months now...
~Luke