I agree with the others, looks more like a mechanical issue. I have a 3 XXL and have had the drag chain catch, here’s how I fixed that:
What’s frustrating is it would catch, then correct itself, so if you weren’t standing by the machine, you may not know. I’ve also had mechanical interference with hold down clamps poorly placed on my part. And I’ve had mechanical interference with things I’ve set on the router table (vac attachment has gotten me a few times…).
Also suggest a full mechanical check. Lots in the forum on this, but high-level:
- Pulley set screws (had mine slip multiple times, detailed fix posted here)
- Belt tension and teeth (had mine stretch causing skips with more aggressive cuts)
- V-wheel tension (slop in the v-wheels may be fine with initial cuts, but get worse as you get deeper)
- Stepper motor screws (make sure they are tight, not moving)
- Electrical connections at the motor and board
I haven’t had any electrical interference issues causing lost steps, but it is possible too. I would rule out all mechanical issues first before trying to chase that down. This past fall, I realized I had an embarrassing number of issues with my 3 XXL, all deferred maintenance on my part. Replaced the belts, v-wheels, checked literally every screw (multiple loose), oiled rails, checked electrical connections, etc. Runs like it’s brand new now.