Y axis movement

List item

The last couple of projects I have had a recurring issue. Midway through the cut one of my y axis moves a different amount them the other side. When I measure the distance from the gantry on both sides there is a difference of 3/8 of a inch or more. This has happened 4 or 5 times now. I have reset the wheels, the nut at the end of the threaded rod, checked screws. But is still happening. Any suggestions?

@KenM Aside from what you have already done, unplug the connectors from both Y motosr and plug them back in, making sure that they are both fully seated. Then run it back to the back until you hear that terrible end-of-the-line noise. That way you know that they are back in sync. If this does not fix it, I’m out of ideas.

Thanks for the info. I have checks that connections are tight. But I will unplug and replug the connectors as you suggested.

@KenM You mentioned the nut at the end of the threaded rod. If you are not referring to the coupler at the motor end, check them, too.

I check them for being tight. I had a issue with the x axis nut(bolt that tightens ion the threaded rod was rubbing on the bushing ) I added a washer to space out the nut. I also did that to the y axis side that seemed to be out .

I’ve had this happen a few times and after carefully checking all my V-wheels I found some loose spots. Also, as Grant said, when you run them all the way to the back and then you get the noise that they are over the limit, walk around the back of the machine and visually inspect. I’ve had one side protest but upon closer inspection I discovered the other side was out 2mm-4mm. They should both appear hard against the rear feet (the vertical gantry plates should be against the feet with no visible gap). If one or the other isn’t, you’re still out of whack.

Once you have them square at the back, run them all the way back to front a few times and visually inspect again and see if they have drifted. On my machine 848mm gets me back to front, but I’m not sure if that is the exact official distance but should get you close.


I will give this a try thank you Jeff, I have done everything you have mentioned except returning it all the to the back to make “the noise”.
I will give this a try. The more I think about it I’m wondering if it could be something with ugs or the servo because it happens mid program run.