Stepper help

So I’m stuck on a stepper problem, my x axis stepper is behaving erratically and I can’t put my fingure on the problem. All the other steppers work fine. I’m using urat 2208s and all the v refs are set the same. But the x axis seems to jitter and move back and forth even when traveling in the same direction (so I command it +10mm and sometimes it moves right and sometimes it moves left) I have posted a video (link below). After the “driver error” I do an m122 everything looks normal but I do have a x register value of 0xC0:0F:00:20. I’m hoping someone has run into this before and can point me in the right direction.

Private video.

But erratic is usually just a poor connection somewhere. The only other thing it has been was travel or feedrates being way out of wack, or the step multiplier being wrong.

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Video should be fixed. I thought about a connection issue and tested it, everything seems good but I will check it again.I say eratic but it is repeatable and somewhat predictable, as in it always moves the commanded distance, I just do not know if it will move in the proper direction. It also never just stops or does not respond. And it always results in the same driver error. Travel, and step multiplier are the same as the y axis that is running smoothly (and should have more mass than the x axis). That said I will try to slowing it down.


Not at the computer to watch the vid but if it changes directions randomly check the direction pin on your stepper driver.

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I would guess a loose wire. Or a loose grub screw.

I’m rechecking the cable now (probably build a new one just to be safe. But how would a loose grub screw make the carrage go in the opposite direction? I will check it anyway but that just doesn’t make sense to me.

I guess you’re right. I was thinking there might be some tension trying to pull it back and the pulley slipped. But there aren’t any forces pulling it back.

ok i thought i was missing something big XD especially since it moved back with precise movements, i could see maybe a little bit of backlash or something but if i commanded +10 move it moved to the right 10mm, then if i did the same command again it would move left 10mm. so i removed the existing cable and tested it again, all came back fine. removed the X driver and looked for issues but did not see anything wrong with the direction pin. so i decided to build a new cable just to be safe. tested it out and it works!

for the record i was really hoping it was the grub screw… now i have to pull everything out of my Z cable chain and re run it with the new wire T_T

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