Calibrate XYZ info and errors
The purpose of the XYZ calibration routine is to measure the skew of the X/Y axes and to find the position of the 9 calibration points on the print bed for proper bed levelling. You can run the XYZ calibration from Settings menu on LCD panel. This should not be necessary on the assembled printers as those are factory calibrated.
Calibrate XYZ is available from 3.0.6 firmware.
Initiating this routine performs a series of measurements in three rounds: In the first round, 4 sensor points on the print bed are searched for carefully as to not touch the print bed by the nozzle. In the second round, all 9 sensor points are found. In the last round, the height above the 9 sensor points is measured and stored into a non-volatile memory for reference.
The progress and results of each step are displayed on the LCD. In case of errors found, the X/Y calibration routine is interrupted and the reason for error is shown to guide users in troubleshooting.
At the start of the XYZ calibration procedure the printer prompts you by a following message:
"Calibrating X/Y. Move Z carriage up to the end stoppers. Click when done.”
After that, the printer asks you to confirm this step:
"Are left and right Z carriages all up?"
Please make sure you really move the Z carriage up to the end stoppers until you hear a rattling sound as the Z stepper motors skip steps. This procedure ensures, that 1) the X axis is perfectly horizontal, 2) the print nozzle is in a known distance from the print bed. In case the Z carriage did not touch the end stoppers, the printer could not possibly know the height of the print nozzle above the print bed and it could therefore crash into the print bed during the first round of the X/Y calibration procedure.
The X/Y calibration procedure also prompts you to:
"Please clean the nozzle for calibration. Click when done."
If this advice is not followed and there is a plastic debris on the print nozzle, then the debris may touch the print bed or even push the print bed away from the PINDA probe, so the PINDA probe will not trigger properly and the calibration will fail.
Error messages and what to do
- "XYZ calibration failed. Bed calibration point was not found." Calibration routine did not find a bed sensor point. The printer stops close to the bed point, which it failed to detect. Please verify, that the printer is assembled correctly, that all axes move freely, the pulleys do not slip and the print nozzle is clean. If everything looks good, re-run the X/Y calibration and verify with a sheet of paper between the nozzle and the print bed, that the print nozzle does not touch the print bed during the calibration routine. If you feel the friction of the nozzle against the sheet of paper and the nozzle is clean, you need to adjust the PINDA probe slightly lower and re-run the X/Y calibration.
- XYZ calibration failed. Please consult the manual. The calibration points were found in positions far from what should be expected for a properly assembled printer. Please follow the instructions of previous case.
- XYZ calibration all right. X/Y axes are slightly skewed. Good job, the X/Y axes are not precisely perpendicular, but still acceptable. The firmware will correct for the X/Y skew during normal printing, so boxes will be printed with right angles.
- X/Y skewed severely. Skew will be corrected automatically. You may consider to re-align the X/Y axes. Still the firmware will correct the skew during normal printing and as long as the X and Y axes move freely, the printer will print correctly.
- XYZ calibration failed. Left front calibration point not reachable. Even if the printer moves the print bed to the end Y end stop, the PINDA probe cannot reach the left front bed calibration point. Move the left Y threaded rod in the Z frame away from you, so the PINDA probe reaches the left front bed calibration point reliably.
- XYZ calibration failed. Right front calibration point not reachable. Even if the printer moves the print bed to the end Y end stop, the PINDA probe cannot reach the right front bed calibration point. Move the right Y threaded rod in the Z frame away from you, so the PINDA probe reaches the right front bed calibration point reliably.
- XYZ calibration failed. Front calibration points not reachable. Even if the printer moves the table to the end Y end stop, the PINDA probe cannot reach the front row of the bed calibration points. Move both left / right Y threaded rods in the Z frame away from you.
- XYZ calibration compromised. Left front calibration point not reachable. or X/Y calibration compromised. Right front calibration point not reachable. or X/Y calibration compromised. Front calibration points not reachable. Printer will most likely work, but the bed levelling may be compromised and the skew of the X/Y axes may not be fully corrected. It is recommended to adjust the positions of the Y threaded rods in the Z frame.