bed levelling not perfctly flat

[LudoJ]

I'm using auto bed levelling function on my A20M.
It world great, but I have a small difference between left and right side. Right side is slightly higher than left side. Not a lot but may be 0.1mm which is enough to cause problems with large prints.

Do you guys have the same issue and do you have any idea of how to fix it ?

[William]

Hi, are you trying to calibrate 3d touch,
You can try in the Repetier Host
M280 P0 S10 ; pushes the pin down
M280 P0 S90 ; pulls the pin up
M280 P0 S120 ; Self test – keeps going until you do pin up/down or release alarm
M280 P0 S160 ; Release alarm

and you can refer to this:viewtopic.php?f=27&t=18371