Y motor random jerking, weirdness

Hi all. I started having an issue with my Y axis randomly making erratic movements in place. See the video I uploaded. I checked my connections, they’re all fine. The jerky movement starts and stops randomly. There is also considerable high-pitched whiting coming from my steppers. is that normal?

If it was working before and is flakey now, I’d put my money on one of the motor wires having an intermittent connection. Look for places where the wires flex as the axis moves. Could also be a bad wire-to-pin connection even if the outer plastic parts of the connectors are still together.


That sounds like a wiring problem. Something is affecting the wiring harness somewhere.

High pitched whine is normal, it happens with almost all stepper motors to some extent. Some drivers are better at reducing it than others, but it’s been there for all of hte stepper motors that I use to greater or lesser extents.

I agree with Tom and Dan that wiring is likely the cause. Grub screws on the connection to the steppers can also cause this problem. There are some low probability causes, but I wouldn’t go there until you ruled out wiring and grub screws.

That’s definitely a connector (electrical) issue.

This helped me a lot to troubleshoot failed wires:

Thanks for the replies everyone. Looks like it was indeed a wiring problem. Replaced a few jumpers and now we’re back in business