[SOLVED] X/Z skewed severly
I've just completed my upgrade from Mk1 to Mk2. I have installed firmware 3.0.6.
If I run the Z calibration, I can see that the probe correctly sits over both the first and last circles on the bed.
I run the XYZ calibration, and it finds the first 4 points, then goes around the 9 points improving the calibration, then eventually reports:
"X/Z skewed severly. Skew will be corrected automatically", then
"XYZ calibration compromised. Left front calibration point not reachable."
I have found this page http://help.prusa3d.com/mk2-movement-calibration/calibrate-x-y-info-and-errors?from_search=13368913 which details some of the errors, but says nothing about "X/Z skewed severly".
Can someone please advise me what I need to adjust to correct this problem?
Re: X/Z skewed severly
http://www.prusa3d.com/3dhandbookMK2 chapter 6.3.5.1 Y axis alignment
Re: X/Z skewed severly
But the error message specifies that it's a X/Z axis problem - not Y axis.
Re: X/Z skewed severly
If you measure distance between the bed and top edge of Z frame, is it the same on left and right side? If not, check correct Y axis assembly in Z frame according to http://manual.prusa3d.com/Guide/4.+Z-axis+assembly/106 step 15. Threaded rods should be pushed all way into Z frame sockets.
Re: X/Z skewed severly
Nearly! The right hand side is just less than 1mm higher than the left.
I guess that I adjust this by where the Y flame is bolted on to the Z frame?
Re: X/Z skewed severly
Yes, try it.
Re: X/Z skewed severly
So, with the printer powered off, I use a digital caliper between the left hand side of the bed and the top of the Z frame. I zero the caliper. I then measure the distance between the right hand side of the bed and the top of the Z frame. The displayed value is difference between the left and right sides.
I then slightly loosen the nuts that make the Y frame grip on to the Z frame, and slightly lower or raise one side, before re-tightening the nuts. This is not an easy thing to do because often tightening the nuts slightly moves the alignment!
Anyway, I have now got it so that there is just 0.8mm in height difference between left of bed to Z top and right of bed to Z top. This is about the best I can seem to get it.
However, the XYZ still fails with exactly the same error! Surely the software can compensate for a linear difference of 0.8mm across the whole X axis can't it?
Anyone got any further suggestions?
Re: X/Z skewed severly
If you can, check the height of X-carriage above the bed (measure distance between X rods and bed on left and right side). It should be the same or have the same difference as frame top edge since you're supposed to align the X carriage with the frame by moving it to the very top.
But generally I'm out of ideas. I don't know what X/Z skew exactly means. Perhaps somebody other knows? Or contact support live chat and give them link to this thread.
Re: X/Z skewed severly
OK, so I've just looked in the source code to try to find out what "X/Z skewed" means. I'm pretty sure that it is a typo in the text, and it really means "X/Y skewed"! I shall therefore treat it as that and adjust my Y frame...
[SOLVED] Re: X/Z skewed severly
I've now managed to fix this problem.
When fitting the PINDA probe, I hadn't realised that there was a nut shaped recess in the plastic part, so I just sat the nut on top of that. This therefore wasn't a very secure fit, so I believe that the PINDA probe must have been wobbling around during the rapid movements of the calibration procedure.
I have now properly fitted the upper nut into its recess, and correctly set the height of the probe.
Doing so has allowed me to complete the XYZ calibration, and adjust the Z level for the first layer.
I am currently 50% into my first print and it all looks good so far.
(I still believe that the "X/Z skewed" text message should more correctly be "X/Y skewed")
Re: [SOLVED] X/Z skewed severly
It shall be X/Y indeed. Sorry for the typo.
Vojtech