Question occasional wrong X/Y home position and layer shifting

[stlfatboy]

Printer Model

voron0.2

Sometime an auto home(start a print job) will let the homing position not in center (as if the head shift 60mm to the left side of the bed), and bumping the left side while printing. I have to do a manual homing before printing.

Also, layer shifting occurs during a 7 hours job. it goes in constant direction (towards door) like a stairstep. A previous 4 hours job is ok with no layer shifting.

Any help is appreciated!!

 

[Sanity Agathion]

Hi, this sounds like sensorless homing is not tuned properly that it detects stops where they should not be. Did you go through guide in VORON documentation to tune it?

Layer shifts can be caused by many things - loose grub screw, not enough current to motors, drivers overheating ... you need to check and try to find out what it is. Depending on which directions those shifts occur, you can determine which motor causes it and go from there. What AB motors do you have and what's your run current?

 

[stlfatboy]

Hi, this sounds like sensorless homing is not tuned properly that it detects stops where they should not be. Did you go through guide in VORON documentation to tune it?

Layer shifts can be caused by many things - loose grub screw, not enough current to motors, drivers overheating ... you need to check and try to find out what it is. Depending on which directions those shifts occur, you can determine which motor causes it and go from there. What AB motors do you have and what's your run current?

Thanks for the reply.

What AB motors do you have and what's your run current?

I'm using siboor R0 kit with fly gemini v3, with default cfg from voron repo.

Did you go through guide in VORON documentation to tune it?

Yes, sensorless homing works ok before (this printer was leaved unused for like 3 months).

Grub screw is locked, belt tavels with no problem.
But during x gantry push back test, some slightly move and shake of the head happens.

I guess the slightly move and shake maybe the reason for both homing and layer shift?

 

[Sanity Agathion]

Thanks for the reply.


I'm using siboor R0 kit with fly gemini v3, with default cfg from voron repo.


Yes, sensorless homing works ok before (this printer was leaved unused for like 3 months).

Grub screw is locked, belt tavels with no problem.
But during x gantry push back test, some slightly move and shake of the head happens.

I guess the slightly move and shake maybe the reason for both homing and layer shift?

That sounds like gantry is racked if toolhead moves with Y movement. It's also theoretically possible that when some motion system parameters change, like tension in belts, the sensorless homing may need to be recalibrated.

Just in case check if your belt is not split or stretched anywhere, this should not happen even after 3 months. Unless the belt is of improper type and it disintegrated.