Y motor seems to be losing torque on X moves
My Y axis just started slipping when my x moves. I think the motor is losing torque or something is slipping. When the X moves the Y also moves a bit.
Not sure where to start? Bad motor? Bad driver? I do have some spare drivers, that I Guess I can test. Could it be that?
This printer has been working really well for a long time, and this just started during my last print.
Now when I try and Ztilt it wont finish the last spot, because it will be driven off the bed.
Thanks for any help
Solution:Jump to solution
OMG.... I'm m kinda embarrassed to report that I found a issue, probably the issue......A timing pulley had slipped off the motor somehow and was just free spinning....sigh
28 Replies
do your toolhead moves in X axis during Y moves?
check the if the pulleys are still tight on the motor shafts.
It does not. Only X moves make Y move
interesting because in both cases both motors do pretty much the same kind of work.
if the pulleys are fine would you mind making a video o the problem?
if pulleys aren't the problem, i'd check the bearing stacks in XY joints, both if belts aren't rubbing on flanges and the bearing themselves, one of them could gone bad, and it's binds during X moves
Ok. Ill make a video tonight.
You can see me moving only the X axis here, and then, homing both x and y. Notice it moves ok on Y only, but when moving X it skips and stutters along the Y, like the motor is skipping or something
Wanted to bump this....im still pretty stumped
What do your input shaper results show? My guess is you have some serious binding going on. How does the gantry move when the printer is off? Does pushing the gantry forward and back in the Y direction also cause the toolhead to move in the X direction?
It feels to move pretty smoothly to me when off. Its hard to move it in a single axis by hand without it sliding in the other. But, it seems to be fine.
Things i would check: grub screws on the pulleys, cable and all the crimps to the motor, smooth movement of the rails and belt allignement.
So, new information. I was able to reproduce the issue with power off. So I think its mechanical, not electrical. It still only happens on X movements, but I can feel it, sorta jump/give/slack etc like there is a definite snapping motion.
I have tried tightening the belts to make sure, and I checked the bearing by hand best I can without disassembling it.
I watched the gears on the motors spin while I manually moved it around, but I didn't see any visible slipping
oddly enough....with power and running the ztilt, it doesn't seem to be slipping anymore
hmmm
well....maybe not...but perhaps it improved, still testing
so, it IS working better
But as you can see, its still shifting sometimes, but not all the time?
So, its worth noting, that I did buy some gates belts instead of the ones that came with it
If I overtensioned the belts could it have caused damage to the motor shafts?
yes, which is why looser is better
It does seem to have a sorta "spot" where it jumps harder than anywhere else.....I guess I need to check and replace some stuff....sigh
How would you guys approach this? Just rebuild the whole gantry?
I would take a systematic approach -
* determine if it is the belts - remove the belts and see if you still have that "spot"
* determine if it is bearings - loosen the belts so the motors are disengaged. Then using your hands move the belt back and forth over each set of bearings. Do they move smoothly?
* determine if it is a motor - remove the belts and have the motor try the same moves. Does it lose steps? is it wobbling?
basically you need to isolate different parts of the system and test them individually
yeah. basic trouble shooting. But I wasn't sure which parts would be the most likely culprit, that is which ones bear the most load from the belts
Hrmm it seems to be a specific spot across the X where it happens the worst
You can feel it sorta lose grip for half a second and yank the Y
I disconnected the belts from the back of the toolhead, and played around pulling them back and forth manually, but didnt feel the same reaction
Solution
OMG.... I'm m kinda embarrassed to report that I found a issue, probably the issue......A timing pulley had slipped off the motor somehow and was just free spinning....sigh
At least I found it before I started tearing it all apart
So many issues in here are something coming loose, glad you found it!
Im not 100% sure thats the only issue, but pretty sure
at least 2 people in this thread suggested you check the pulleys... it's a lot easier to help if you check the suggestions when they happen.
Blue thread locker helps to keep them from backing out
I did check them...but the embarrassing part is how I checked them....lol. I looked up and saw that they were spinning just fine.....I totally didnt think to look to see if the motor shaft was also spinning
In my defense, I only get time to work on it after 10pm and I wake up around 6am
lol