XYZ Calibration Hell  

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ianstock
(@ianstock)
Active Member

My Mk2.5 worked fine for months and then required a calibration. I have tried everything I can think of including using a digital micrometer to measure alignment of Z-axis frame and checking bed height.  (One side of the bed is about 1/32" above the other.)

I have moved the PINDA up and down and think I have it in the right place.  The nozzle is just off the bed when it calibrates.

When it does the 1st iteration of the XYZ Calibration, at the 2nd location (right side of bed) the head doesn't get anywhere near the bed and only takes 2 or 3 passes before moving on.

I get the dreaded XYZ Calibration failed.  Consult Manual error.

I am at a total loss.

 

Ian

 

Posted : 09/05/2019 11:12 pm
Tim
(@tim-m30)
Illustrious Member

No experience with a MK2.5, but on a Mk3 the XYZ can fail if the HOME position is off.  E.g., if something keeps the extruder from getting all the way left, it creates an offset and the cal points can be over shot when the calibration runs.  

 

But then there's this:

https://github.com/prusa3d/Prusa-Firmware/issues/764

This post was modified 1 year ago by Tim
It is always wise to get more than one opinion......
Posted : 10/05/2019 9:06 am
ianstock
(@ianstock)
Active Member

I keep getting the same failure but have no idea where to start looking for the fix.  Is there a diagnostic tool that will tell me what is wrong other than simply saying "fail"?

 

Posted : 10/05/2019 4:06 pm
ianstock
(@ianstock)
Active Member

I have found the XZY Calibration Details.  What does it mean when the result is:

Y distance from min:

Left: 4.54 mm

Centre: 4.45 mm

Right: 4.36 mm

 

Posted : 10/05/2019 4:08 pm
ianstock
(@ianstock)
Active Member

and "Measured Skew: 0.95 degrees

 

Posted : 10/05/2019 4:11 pm
Tim
(@tim-m30)
Illustrious Member

Here's some Prusa info that discusses XYZ numbers... I believe the numbers represent the distance from home to each of the reference dots in the heat bed. Ideally the distances should be equal. But if the bed is rotated, i.e., the Y rods not perpendicular to the X axis, you see differences between left and right.

https://help.prusa3d.com/article/PBlnvMN6pt-xyz-calibration-details

https://help.prusa3d.com/article/fja7hbb22y-xyz-calibration-error-messages-mk-3

 

ps: I searched Google to find those links. My query was:

what do the xyz calibration details mean on prusa printers

To be honest, I've never had issues, but my skew is only 0.03 degrees.  And I have a Mk3.

This post was modified 1 year ago 2 times by Tim
It is always wise to get more than one opinion......
Posted : 11/05/2019 10:37 am
gnat
 gnat
(@gnat)
Prominent Member

I just went through this with my 3S yesterday after rebuilding my extruder. The XYZ calibration kept failing to find the first point and the knowledge base was useless. 

Finally on a whim I reran the self test and that reported a problem with my X axis. Turned out even though I thought it was moving well, but apparently there was enough friction to trip it up (I have Drylin bushings on the X and over tightened them). 

So try the self test and see if it gives you more info. 

MMU tips and troubleshooting...
Posted : 13/05/2019 3:01 am
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