Original Ultimaker, X-axis stops moving intermittently - solved

[modemch 0]

Hi,

I have an original Ultimaker, with a self-built heated bed (powered by mains, so no additional load on the main board). The belts are tight, but not too tight - I can move the head with two fingers, as long as the axes are oiled. Other than that the printer is unmodified.

Recently the printer started to have a problem with layers shifted on the X-axis, and now it's happening pretty much constantly. I got it on video at

- about a minute in, as it's doing the infill, you can see that the X-axis stops moving for a second or so, and then resumes. I've also seen it jump, maybe 50 millimeters or so, print a bit there, and then jump back approximately the same amount. The clicking in the video is much less noisy in person, and appears to be benign - the belts don't appear to be skipping steps or riding up the pulleys.

I've tried swapping the X&Y stepper drivers, but the problem did not move to a different axis. I'm at a loss at this point, unable to print anything. Thanks in advance for any help.

 

[gr5 2,172]

It's most likely one of the 2 X limit switches. Are the cables getting tangled up in the belts maybe? When a limit switch triggers for a given axis the other axis keeps going.

You can unplug the X switch on the right side as you really don't need it. Marlin has "software endstops" which work quite well. If that's the problem switch then you are "done". If it's the left one you have to figure out whats going on. I would turn off power and hook up a multimeter to the far end of the limit switch cable (under the UM) and then push the head around and poke at the wires and such.

 

[modemch 0]

It's most likely one of the 2 X limit switches. Are the cables getting tangled up in the belts maybe? When a limit switch triggers for a given axis the other axis keeps going.

You can unplug the X switch on the right side as you really don't need it. Marlin has "software endstops" which work quite well. If that's the problem switch then you are "done". If it's the left one you have to figure out whats going on. I would turn off power and hook up a multimeter to the far end of the limit switch cable (under the UM) and then push the head around and poke at the wires and such.

 

Thanks, I'll check this out. I do have an Ulticontroller though - wouldn't it say that a limit switched was hit if this was the case?

 

[modemch 0]

Actually, upon some introspecting I've realized that I haven't heard the electronics fan in a while, and after checking it was barely spinning. Adding some oil made it spin much better, and so far the same print is going much further than it got in the past. Looks like the stepper driver was overheating and shutting off intermittently, most likely my x-belts are tighter and require more current.