Z-compensation uneven - higher on one side

We are trying to print, with Marlin 1.1.0, RC2 on a Prusa i3 steel on a print bed of 0.8mm machined aluminium (really even!), and using an inductive sensor for the auto bed leveling.

We send first G28, then G29, then start the print. The auto bed leveling is in fact compensating for the tilt of the bed, but unevenly: while the nozzle hits the proper height on the right side of the bed, it prints in the air on the left side on the bed. This happens with all kinds of different tilts.

We tried:

- different ways to tilt the bed (higher on left, higher on right, good manual levelling). The result is always the same, on the left side the nozzle is always a little too high (maybe about 0.5 mm).
- adjust the position of the pieces on the threaded rod (left side higher than right, right side higher than left, both sides same height). We get the same result.
- measure 4 or 9 grid points

Is there any way to adjust this in the firmware? Or any other reason why this happens?



Thank you for your time.

I have exact same issue.

Did you resolve it ?

You might want to try the devel_ubl branch. You get to dial in the height of the bed at every mesh point.

I am using mesh bed leveling now - it works much better and is not complicated. Just needs a few lines uncommented in the firmware and it now prints perfectly well. No more autoleveling for me!