Z calibration perpetual fail.
For a couple of weeks now my z-calibration has been failing. The printer works and prints well but suddenly the calibration including the wizard fails on the z-calibration test. It seems to complete the z-calibration but then it just says failed and another message. I recall reading something about this as a known issue but I cannot find the post I read.
Re: Z calibration perpetual fail.
I think I've read a few reports that indicate the Z cal will fail if started when the extruder is low, near the bed. People have said that starting the cal when the extruder is within a couple cm of the top the cal will home the Z against the top stops, then continue down and allow completion.
Re: Z calibration perpetual fail.
I have tried it at the bottom, top, close to the top, close to the bottom, middle, close to the middle and no go...fail every time. I wish it was as simple as that but whatever is happening is new, possibly introduced with a firmware but I am not sure.
Re: Z calibration perpetual fail.
are you sure you have the correct firmware for your model?
I have a Prusa,therefore I research.
Re: Z calibration perpetual fail.
Hello - so, firstly, I am a newbie to 3D printing. I completed the assembly of my MK3S today. I'm not however, new to engineering or CNC machines so the following was a "troubleshooting process" I performed on my MK3S. After assembling my MK3S kit, I had a failure during the XYZ calibration - specifically the Z calibration where the climb of the Z axis to the top failed for initial 4 sensor point calibration. I tried to calibrate this machine several times with differing Z- start points but the same failure type persisted.
As I progressed through the troubleshooting process, I noticed a somewhat "tighter" left Z-axis motor screw compared to the right one (turning with my finger and thumb). Turning the left screw by hand was definitely more difficult than the right hand screw. I could not get the calibration to pass with the assembly as it was.
Through some deductive reasoning, I assumed there was "drag", or "friction" being introduced somewhere. As such, I loosened (enough to release stresses) the four screws holding the left Z-axis motor from the lower Z-motor mount (4 of them), loosened the screws holding the left axis T8 nut (2 of them, again, to relieve stresses) and low and behold, calibration completed successfully. I performed the calibration several more times as I gradually tightened the motor and T8-nut screws to "comfortable" torques.
My point here is that you may be dealing with just marginal friction in the z-axis motors that intermittently, or perhaps, in your case, persistently, causes Z-axis movement failures through whatever process is being utilized in the firmware.
It may be helpful to test for T8 screw tightness and relax some of the mounting screws. This worked for me in the case mentioned above. FWIW.
Tony
Re: Z calibration perpetual fail.
Oh, and BTW, I also backed off, a 1/4 turn or so, the two "screw caps", the two black cones screwed down the Z-axis T8 thread presumably used as a dust guards between t8 screw and Z-axis stepper motor. Wanted to make sure this was not a contributing factor. Again, FWIW.
T
Re: Z calibration perpetual fail.
are you sure you have the correct firmware for your model?
Actually no I am not 100% sure I am using the correct firmware. I purchased an MK3 but then upgraded to the MK3S. So I assumed that my printer is now the MK3S and I applied the 3.7.0 firmware from the MK3S section, not the MK3 section.
Re: Z calibration perpetual fail.
Hello - so, firstly, I am a newbie to 3D printing. I completed the assembly of my MK3S today. I'm not however, new to engineering or CNC machines so the following was a "troubleshooting process" I performed on my MK3S. After assembling my MK3S kit, I had a failure during the XYZ calibration - specifically the Z calibration where the climb of the Z axis to the top failed for initial 4 sensor point calibration. I tried to calibrate this machine several times with differing Z- start points but the same failure type persisted.
As I progressed through the troubleshooting process, I noticed a somewhat "tighter" left Z-axis motor screw compared to the right one (turning with my finger and thumb). Turning the left screw by hand was definitely more difficult than the right hand screw. I could not get the calibration to pass with the assembly as it was.
Through some deductive reasoning, I assumed there was "drag", or "friction" being introduced somewhere. As such, I loosened (enough to release stresses) the four screws holding the left Z-axis motor from the lower Z-motor mount (4 of them), loosened the screws holding the left axis T8 nut (2 of them, again, to relieve stresses) and low and behold, calibration completed successfully. I performed the calibration several more times as I gradually tightened the motor and T8-nut screws to "comfortable" torques.
My point here is that you may be dealing with just marginal friction in the z-axis motors that intermittently, or perhaps, in your case, persistently, causes Z-axis movement failures through whatever process is being utilized in the firmware.
It may be helpful to test for T8 screw tightness and relax some of the mounting screws. This worked for me in the case mentioned above. FWIW.
Tony
All of the tests that I have completed show that misalignment, binding and friction is not an issue. However I am open to trying more tests, do you have any specific tests that you can recommend?
Oh, and BTW, I also backed off, a 1/4 turn or so, the two "screw caps", the two black cones screwed down the Z-axis T8 thread presumably used as a dust guards between t8 screw and Z-axis stepper motor. Wanted to make sure this was not a contributing factor. Again, FWIW.
T
I tried that one, but no love.
Re: Z calibration perpetual fail.
@michael - Take a photo of your printer, front and back, and post them here. And try for a good closeup of the two Z-Axis caps at the top of the printer frame. Often a photo is worth hours of describing.
RE: Z calibration perpetual fail.
@michael - Take a photo of your printer, front and back, and post them here. And try for a good closeup of the two Z-Axis caps at the top of the printer frame. Often a photo is worth hours of describing.
I am not sure what pics will tell you unless you believe that I was unable to recognize that the frame, rods and screws were visually misaligned, which they are not.
Also, it appears that this new "improved" forum will only allow me to attach one pic using the "Attach file" option, the "Insert/edit image" option is just completely unintuitive, so I have no idea on how to use it.
RE: Z calibration perpetual fail.
I am still having this Z-axis calibration fail. It has now persisted through all the iterations of firmware, up to the most current, since I started this thread. I can't just be the lucky one who has experienced this?
RE: Z calibration perpetual fail.
You may want to ask Bondtech what is happening since you are no longer using a stock extruder. Lots of games with heights and positions when using non-standard configs like yours, even may need different firmware.
RE: Z calibration perpetual fail.
@tim-m30
I will revert to the stock extruder and see where this goes.