Failed XYZ Calibration
Hi everyone!
I'm having an issue with my new MK3s kit. I assembled the printer and ran the wizard with no problems, and managed to get some excellent prints from the supplied models. Shortly after I had to move the printer to its permanent home. I printed the vase after the move and it printed excellent, but it did seem to have issues when printing across the whole build plate. At this point I updated the firmware to 3.7, and decided to re-run the setup wizard, but the printer failed the XYZ calibration and told me to consult the manual.
From this point i have tried lowering the Pinda probe (i got as low as .6mm by feeler gauge and raising the Pinda probe to apox 1.4mm but it hits the bed at that height.) and still got the same errors. I updated to the newest firmware (released on May 13 3.7.1 i think?) Still failed. I followed the instructions on a "hard reset" and still had the same errors. I loosened all of the frame bolts and then tightened them and still cant pass the calibration. I've tightened and loosened the u-bolts on the Y axis, and tightened the X and Y belts. I still cannot get the machine to pass the calibration. Is there something else i should be looking for? I have to admit I'm very frustrated and sick of troubleshooting right now, so any help would be appreciated!
Thanks,
Jamie
RE: Failed XYZ Calibration
At which stage the XYZ calibration fails? Can you connect to the printer via a terminal? It sends a lot of useful information over USB to a terminal that can help pinpointing why the XYZ calibration fails. Most often, however, it is that the printer can't smoothly move to all the maximum X Y Z positions, because eg. cables or something else interferes with the motion during the calibration.
RE: Failed XYZ Calibration
Thank you for the reply!
it doesn't fail until after finishing the 4'th point of the calibration test. The self tests all come up ok. As far as i can tell the cables etc... are all out of the way.
I'm new to some of this, so i apologize in advance, but what type of terminal? i have my laptop that i can plug into it if that works. If there are instructions somewhere on where/how to do this ill gladly do it. I think that now knowing where to start is probably my biggest issue. I know something is off, i just cannot figure out what it is!
Jamie
RE: Failed XYZ Calibration
On Linux, I use 'minicom', on Windows, you'd probably use something like 'PuTTY'. If you look for 'terminal emulator' programs, those are programs that allow sending and receiving characters over a serial line. Such a program would allow you to talk to the printer at the gcode level manually and see what the printer thinks or is doing.
RE: Failed XYZ Calibration
Also, is there any message on the screen when it fails? I could cross-reference that to the firmware sources to see what it was trying to do at that time.
RE: Failed XYZ Calibration
Thanks for the info on the emulator also! I appreciate that, will look into that as soon as i can!
The error that displays on the LCD is (to the best of my memory) "XYZ calibration failed. consult the manual"
RE: Failed XYZ Calibration
That message corresponds to the
BED_SKEW_OFFSET_DETECTION_FITTING_FAILED
state. And that state is reached when the printer thinks the positions of the four calibration points it detected are not square. Are you sure you're calibrating with the PEI sheet removed? Is the printer homing in on the four round calibration points on the PCB correctly? (In the last phase of the calibration when it's doing a star pattern movement above the points.)
The terminal output would be very helpful in this case.
RE: Failed XYZ Calibration
The steel plate is definitely off when I'm testing. I've been using just the heat bed. when it is calibrating it seems to my eyes that the probe is over the target circles. I cannot tell if it is centered, but it is close if not perfect.
Is there something that could be loose that would cause the skew, the frame misaligned, or something in the x- axis too? Not sure this is related, but when the printer was first assembled, and I checked the skew i had a number of .03 Now, every time i run the xyz calibration and check the "skew" on the LCD it has fluctuated. any where from .06 to .31 and the last several checks it was going back down. I don't mind tearing down the printer, i just want to keep the tear down as minimal as possible.
Thanks for helping!
RE: Failed XYZ Calibration
What could be loose? X and Y pulley set screws (one must be against the flat). Belts. Y bearings. Y rod holders. Z holders. X carriage. PINDA.
The set screws could cause these symptoms.
RE: Failed XYZ Calibration
Loose belts might be related, but more common is loose drive gears.
Flat First: Drive gears must be tightened flat-first.
1) Start with both set screws fully loosened so the pulley is free to spin on the motor shaft.
2) Align one set screw dead center with the flat on the motor shaft, slowly tighten the screw until it fully contacts the flat surface.
3) Torque the flat set screw to spec.
4) Now tighten the jam set screw, and torque it to spec.
Once tightened, never touch the flat set screw unless the jam screw is first fully loosened.
Why Flat First? Set screws have flat ends. If you tighten the jam screw first the set screw on the shaft flat doesn't fully contact the shaft, only one small edge of the screw surface is biting. Reversing torques can easily shift the shaft to a position the flat screw no longer contacts the shaft. This lets the jam screw wriggle loose. And after a while, vibration loosens the screws until the gear is free to rotate.
RE: Failed XYZ Calibration
so in short... everything 😊
that's what i expected.
I'm going to try the motor set screw technique that was suggested below. If that doesn't work I will download PuTTY and see if I can figure that out. I will add the info I find when I get it and hopefully understand it.
again thanks for you assistance!
RE: Failed XYZ Calibration
Loose belts might be related, but more common is loose drive gears.
Flat First: Drive gears must be tightened flat-first.
1) Start with both set screws fully loosened so the pulley is free to spin on the motor shaft.
2) Align one set screw dead center with the flat on the motor shaft, slowly tighten the screw until it fully contacts the flat surface.
3) Torque the flat set screw to spec.
4) Now tighten the jam set screw, and torque it to spec.Once tightened, never touch the flat set screw unless the jam screw is first fully loosened.
Why Flat First? Set screws have flat ends. If you tighten the jam screw first the set screw on the shaft flat doesn't fully contact the shaft, only one small edge of the screw surface is biting. Reversing torques can easily shift the shaft to a position the flat screw no longer contacts the shaft. This lets the jam screw wriggle loose. And after a while, vibration loosens the screws until the gear is free to rotate.
Thanks for this! while I am "pretty sure" that these are OK I know I have loosened them while trying to troubleshoot on my own, so i will go through this process to make sure they are properly installed.
RE: Failed XYZ Calibration
So I took Tim’s advice and checked the gears. One was canted a bit. I went through the process again and was able to get it to pass the xyz with the parallel result! Your help was invaluable!
im still having some issues, but making progress. I test printed a benchie and received a notice that the crash detection was activated 6 times on the y axis.
The first layer isn’t perfect across the plate either but I think I can fix that with the calibration tweaks, but as always I’m new to this printer and very open to advice!
thanks again for all the help!