Stepper problem?

I was cutting some plastic today and all of a sudden one of my steppers started acting up. I have linked a video

I am using an SKR Pro with 2209 drivers and dual end stops, its been running flawlessly.

I have checked all connections, wiring, bearings, everything I can think of. I can shut off the unit and move it by hand and it’s smooth all the way through travel. I swapped the drivers around to make sure it wasn’t a driver problem. I loosened the belts and ran the motor without any resistance and it runs fine, but as soon as I put the belt back on it starts doing this again. I think maybe the stepper motor itself? It is only this one motor and it happens either direction.

  1. check your grub screws. The pulleys may be slipping on the motor shaft.

  2. if you can, before you turn off the machine, after this kind of trouble, send M122 and take a look at the response. If there is a loose connection or it is overheating, there are flasg to indicate that.

Grub screws are tight. M122 doesn’t show anything out of normal

Well I swapped a stepper and it’s doing the same thing so definitely not a motor

The video makes it look as if the motor goes cranky when it passes an opening in the spoilboard- but it can only be a coincidence…

Well I figured it out. I traced it down to a bad wire to that stepper. I am using the tape measure trick for wire management and when the tape would flex in a certain spot it was causing the motor to miss steps. I have pulled all the wire and it actually looks fine, but I guess there is a broken spot somewhere.

I will get the wires replaced and should be good to go…

The good news is I now have all new firmware loaded and have thoroughly gone through the whole machine. :slight_smile:

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That’s great! Should be good for a while now.

I am surprised the tmc didn’t say OLA or OLB from M122.

New wires to that stepper solved the problem.

My guess is it was reading fine in the position that I ran the M122? No idea… crazy issue but solved. Thanks for the help!

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