XYZ Calibration & error messages (MK3)

Updated 4 months ago ​by Tomáš Chvalina

XYZ calibration is the decisive process which will tell you how well you have assembled your printer. Essentially, it measures the skew of your X/Y axis, and compensates for any imperfections. It may indicate two sets of error messages [compromised/failed]. See below for detailed description.

XYZ calibration is done directly through the Wizard on the printer's LCD screenSimply press [yes] once the printer asks if you want to run it. Or you can manually start the Wizard from the LCD Menu - Calibration - Wizard.

If you are just fine-tuning the XYZ calibration and you have finished the Selftest successfully, you can start the XYZ calibration separately through the LCD Menu - Calibration - XYZ cal. 

Calibration walkthrough

  1. The printer will start the calibration by aligning the Z-axis. Make sure that both X-axis ends reach the top.
  2. In the next step, the printer asks whether you have the steel sheet on the heated bed. Remove the steel sheet for the upcoming initial 4 point calibration now and select [No]
  3. Check that the nozzle is clean and confirm the on-screen prompt.
  4. Place a sheet of paper (e.g. shipping checklist) between the nozzle and the heated bed. - If the nozzle catches on the paper, immediately press the Reset button and check some of the tips below. Do not leave the printer unattended during this whole part, otherwise, you may end up with a scratched heatbed. 
  5. Once the first routine finishes, place the steel sheet on the heated bed and confirm the on-screen prompt. The printer will perform full 9 point mesh bed leveling. All of the measured compensations will be stored in non-volatile memory.
Do not forget to check out our video "Original Prusa i3 MK3 guide for a new user" where we cover the whole calibration. 

What does each of the error messages mean?

Initial XYZ Calibration error messages

"XYZ calibration failed. Bed calibration point was not found."
= Printer was unable to perfectly pinpoint the initial calibration point.

"XYZ calibration failed. Please consult the manual."
= Calibration point was not found at all.

"XYZ calibration failed. Left front calibration point not reachable."
"XYZ calibration failed. Right front calibration point not reachable."
"XYZ calibration failed. Front calibration points not reachable."

= Printer was unable to find Left, Right or Front calibration point. 

"XYZ calibration compromised. Left front calibration point not reachable."
"XYZ calibration compromised. Right front calibration point not reachable."
"XYZ calibration compromised. Front calibration points not reachable."

= Your printer was able to finish the initial calibration. However, your Left, Right or Front calibration points were just in the middle of passing the calibration or failing it. That means you should be able to use your printer. Yet we advise to check out following tips on how to improve your XYZ calibration.

Mesh bed leveling error messages

"Bed leveling failed. Sensor didnt trigger. Debris on nozzle? Waiting for reset."
"Bed leveling failed. Sensor triggered too high. Waiting for reset. Bed leveling failed."
"Sensor disconnected or cable broken. Waiting for reset."
= Your printer was able to finish the initial calibration. However, there is something wrong with the P.I.N.D.A. probe position.

If you ended up with "XYZ Calibration / Bed leveling failed..." please follow the instructions below.

Improving the XYZ calibration

If you encounter any of these error messages, there is most likely something wrong with the assembly of your printer.

Please perform the following tasks:

  1. Make sure you followed the instructions on the LCD precisely. Especially make sure that the X-axis was moved to the very top. Otherwise, the Z-axis might be misaligned. 
  2. Make sure that the cable harness leading from the extruder does not hit the cover of the EINSY RAMBo board before it reaches the end of the X-axis. 
  3. Check the E-axis assembly. Make sure that the hotend is perfectly inserted in the extruder. 

  4. Make sure nothing blocks the movement of any of the axis. You can easily test that by moving the extruder or heatbed through LCD Menu - Settings - Move axis [X/Y]. Simply move it from one end to the other and inspect the movement.
  5. Go to LCD - Calibration - Auto-home. The P.I.N.D.A. probe must stop in the center of the 1st calibration point  (check the photo below). If it does not, then there is something misaligned in the assembly of your axis. 

  6. Make sure that your PINDA probe is roughly 1 mm higher than the tip of the nozzle.

  7. It is rather unlikely, but there is a small possibility that your P.I.N.D.A. probe could be defective. The easiest way how to check that is to navigate to LCD Menu - Calibration - Show endstops. While placing anything metal (e.g. a spatula) under the P.I.N.D.A. probe. The endstop reading should change from 0 to 1. More information can be found in PINDA Probe testing.
If you have just recently updated your Firmware version and XYZ calibration is failing without any logical reason, navigate to LCD Menu - Calibration - Reset calibration. Once it's done, simply restart the calibration process and see if it makes any difference.

Do not hesitate to contact us at info@prusa3d.com. If you have any further questions.


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