Strange bed distortion on delta machine

Furbyhaxx

Hi folks. I have a long lasting problem with my delta machine (TEVO Little Monster).
I use the nozzle as probe (24v to nozzle, GND to aluminium bed)and custom magball arms.

Auto bed leveling gives me this S-curve warped bed but it actually is flat min max is -0.2/+0.6mm according to auto leveling.
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What could cause this? I don't know any further..

Veti

try 8 or 9 factor compensation. this will most likely fix it.

Furbyhaxx

@Veti I'm not sure if I tried this already, but will do it again.

But what's the cause of this?

Furbyhaxx

@Furbyhaxx 8 factor calibration did not work..

Veti

strange it looked like
http://boim.com/DeltaUtil/CalDoc/Calibration.html
Tower Placement Symmetry

lord binky

@Veti It is, calibration only compensates for tower angles off of a perfect equilateral, not tower distance from center or individual arm length short/long. Shim the joints on the carriages of the two good towers to compensate for one that is inset, or shim the offending tower if it is too far away from center. As long as the lengths of the rods are equal per each tower (it twists the effector if not) you can compensate that manually with M665.

droftarts

@Veti said in Strange bed distortion on delta machine:

strange it looked like
http://boim.com/DeltaUtil/CalDoc/Calibration.html
Tower Placement Symmetry

That, and incorrect rod length, I’d say.

Ian