I was trying my fifth or so rotary carve and, as recommended, went through the calibration menu. Started the calibration, marked my material, hit enter, and it rotated actually about 3 and 1/2 times around, then it slowed down and kept rotating, about 50 seconds per rotation. That never stopped. I tried several times, tried turning the machine off and on, tried reseating the memory card, tried a different memory card, tried reinstalling the rotary jig, tried pushing down even harder on the head, but it kept doing this. So I tried doing a rotary carve (a rotary lithopane), and it carved the first row, then went into the slow rotation and kept on doing that. Clearly something is stuck or missing somewhere. Did I knock something loose? I did blow the sawdust out of the machine just before this, but I didn't stuck the blower into the machine itself. I hope not, anyway.
Any suggestions welcome.