XYZ Calibration failure
I am a embarassed to say that the XYZ 4 point calibration keeps failing. It says check the axis but I am not sure what to look for since I thought I had it built right. The y axis moves freeley, The X axis moves fine, the Z axis is a bit stiff to manually raise the extruder with the right side a bit tighter than the left. The initial XYZ calibration is "OK" and then the 12 minute calibration starts. Extruder finds "home", then as soon as it drops to the bed, "Calibration Fail". It is not touching the bed, paper moves freeley. I have adjusted the PINDA probe several time, same result.
RE: XYZ Calibration failure
This unit did not run the z axis all the way to the top in initial quick calibration. I just tried to do it by using the control knob and it will not go all the way to the top. It stops an inch from the top.
RE: XYZ Calibration failure
Wow, this actually just happened to me as well and I came here looking for answers. In my case, the left side is the tighter one. When the Z-axis starts moving up to "level" itself, it stops about 70mm or so above the bed, thinking it's reached the top (I presume since it's sensing the increased resistance from the left side), and the right side goes up a couple more millimeters, making the X-axis skewed. Just to see what would happen, I continued the calibration (knowing it would fail, with my hand on the Reset button), and it displayed "Calibration failed! Check the axes and run again."
So essentially what's happening is my left Z-axis is getting stuck and preventing calibration from finishing. Even if it could finish, the printer definitely can't run in it's current state. At first I thought it might be a stripped or dirty thread on the trapezoidal nut. However, I removed both trapezoidal nuts and was able to thread them freely on the entire length of the lead screws without any resistence. I even cleaned the threads gently with an old soft toothbrush and canned air. In addition, I swapped the trapezoidal nuts from left to right (to see if the problem moved to the right side). The problem stayed on the left side, thus indicating the problem was not the trapezoidal nut.
Alas, I fear the left Z-axis lead screw is likely bent/warped to some degree. I removed the smooth rods, and the left side still gets stuck (and the smooth rods both appear to be straight). Since the lead screws seem to be permanently mounted to the stepper motors, I will likely need to reach out to Prusa to see if they can send me a replacement stepper motor Z-axis assembly for the left side. This is my second time assembling an MK3S, and it all went smoothly until I got to this point. Hopefully I can get it resolved soon.
RE: XYZ Calibration failure
After working with support via the online chat, we determined the left Z motor was likely bad. They are sending me a warranty replacement, which should also include the pre-attached lead screw (just in case there is somehow a bend in the current one as well).
RE: XYZ Calibration failure
@scyanix
Hello,
I will discuss this with them as well. If it is bent it must have arrived that way. Thank you
RE: XYZ Calibration failure
Ok, today is a new day. This morning the z axis is not as stiff and the XYZ calibration completed with ease. The only thing I did differently was to reset statistics when I selected factory reset. Last night I did not do that in my multiple factory resets. The Z axis never attempted to raise to the top last night today was totally different. Not sure why that is. At this point the x/y calibration is perpendicular and moving forward