MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration
 
Notifications
Clear all

MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration  

  RSS
mcmillion
(@mcmillion)
Active Member
MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

I assembled my MK3 kit a few weeks ago and everything has been fine. I've basically been printing nonstop with minimal issues.

Suddenly today, prints wouldn't make it past mesh leveling. I went in to redo the XYZ calibration and it won't make it past the second position, usually bombs on the first. I've redone the probe position by laying the nozzle down (almost) on the bed and using a zip tie to space the probe, but no luck. I've also tested that the probe is working with a flathead screwdriver. Any ideas?

Posted : 12/03/2018 4:58 pm
thrawn86
(@thrawn86)
Honorable Member
Re: MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

firmware version? why can't it complete? nozzle crashing?

Posted : 13/03/2018 1:35 am
x50arm
(@x50arm)
Estimable Member
Re: MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

Try wiggling the cabling coming out of the extruder while watching the light on the Pinda probe. Mine had an intermittent break in the blue wire going to the Pinda probe about one inch past where you zip tie the cabling to the extruder. When static it would appear good, but fail when it moved. I wound up splicing in a piece of wire to get back up and running. There was no evidence if physical damage to the cable jacket or wire insulation that would have led me to find this otherwise. Good luck in your troubleshooting.

Posted : 13/03/2018 2:01 am
mcmillion
(@mcmillion)
Active Member
Topic starter answered:
Re: MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

So after leaving it for a bit I tried it again tonight and after a few weird attempts it calibrated just fine and has been printing just fine ever since.

I say weird because the screen was showing abnormal things during the calibration. I managed to think to snap a shot of one. Maybe it's firmware issues?


firmware version? why can't it complete? nozzle crashing?

I'm on 5.1.1

It's not crashing, it just says it can't find the point.

Posted : 13/03/2018 3:11 am
thrawn86
(@thrawn86)
Honorable Member
Re: MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

does the light on the probe blink when it moves over the point?

latest firmware is 3.1.3, check the downloads page prusa3d.com/drivers

Posted : 13/03/2018 9:46 pm
mcmillion
(@mcmillion)
Active Member
Topic starter answered:
Re: MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

After a couple of days of printing just fine, it's failing to calibrate again.

I recorded a video of what's happening. The probe makes it to the third position and then bombs. What's weird is if you move the steel plate the probe definitely picks it up.

From what I can tell, there are no shorts in the probe wiring.

I've also updated to 3.1.3 with no change.

Posted : 16/03/2018 5:50 am
mcmillion
(@mcmillion)
Active Member
Topic starter answered:
Re: MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

So I just noticed that the right Z-axis was WAY off (it was a good 5-10mm higher than the left). Sure enough, Did the Z-axis all the way to the top and let them level out and it calibrated just fine.

Now my question is: why is the Z-axis getting out of sync over time? They both turn smoothly and nothing seems to be binding.

Posted : 16/03/2018 6:46 am
solhaga
(@solhaga)
Eminent Member
Re: MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

This can happen if the screws on the trapezoid nuts are tightened too much/uneven.
The nut is then skewed against the threaded rod of the z-axis and it cannot run freely.
It could also be the plastic cover that are tightened too much at the stepper motor.

Posted : 16/03/2018 7:00 am
michael.r52
(@michael-r52)
Eminent Member
Re: MK3 has been working fine for weeks, suddenly today can't complete XYZ calibration

Since the Z axis are wired in parallel one of them is probably getting an intermittent signal, perhaps a loose connector or broken wire. Try moving the Z axis using the menu up near max Z up and down a bit so you can try to see which axis is the problem. If you are able to do the z calibration then the software won't let the axis hit the max Z when moving from the menu. If an axis hits the top after calibration, then its the problem. If using the menu you move to the max Z and the axis are uneven then the lower one is the problem.

Posted : 16/03/2018 7:15 am
Share: