Inconsistency in height calibration.

[Brmatt]

I'm running a duet on a seemecnc Rostock Max V2 and I have been having trouble with the height. Every time I change the parameter it seems to move the head inconsistently. For example, If the height is 2mm to much, so I take off 2mm, I will bring it to the bed again and it will be 1mm too little. It seems to not be consistent in its movement.

[sungod3k]

if youre 2mm to low, then you smashed in to the bed and probably skipped some steps.

you should be able to home and the move down slow and controlled until you reach the bed. then you read the z height and use that.

if your measurements are inconsistent then something is loose in the arms, hotend, belts or frame.

or you get yourself a z probe

[dc42]

@brmatt said in Inconsistency in height calibration.:

I'm running a duet on a seemecnc Rostock Max V2 and I have been having trouble with the height. Every time I change the parameter it seems to move the head inconsistently. For example, If the height is 2mm to much, so I take off 2mm, I will bring it to the bed again and it will be 1mm too little. It seems to not be consistent in its movement.

Which parameter are you adjusting? Do you have a Z probe, and if so, what sort?

[Brmatt]

@dc42 no z probe and i am mainly adjusting the rostock's height parameter:

[dc42]

Are you certain that your endstop switches are triggering at the same positions consistently, and that motion of your printer is smooth without excessive friction?

The usual way to calibrate without a Z probe would be to set the Z probe type to 0 in the M558 command and run auto calibration as usual (you will be prompted to jog the nozzle down to the bed at each probe point). But this won't solve a height inconsistency at a fixed XY position.

[Brmatt]

I am fairly certain the end stops are consistent yes. I wonder if there is something involving the belts or maybe the motors causing this inconsistency.