On second thought; the problem might be me, not the steppers. My vario doesnt have quite the motion range of the stepper (~230 vs 270 degree?), so on every power cycle, I bump the needle against the edges to calibrate/center. In my defense, the stepper itself seems to do this too, it doesnt seem to have internal endswitches, so I assumed this was fine. But now Im guessing this is causing me to strip the plastic gears. I'll need to add a microswitch or optical switch or something to detect a known needle position, and use that to calibrate its position. If anyone has suggestions for something SMALL, Im all ears.
Meanwhile, I'll put one stepper at work non stop without the LCD cover, so it cant bump in to anything, and see how that fares.