I have issue with marlin 1.0.2 auto-leveling.
I level out the bed that when after command G28 I move hotend around it stays flat, however the measurements of inductive sensor on G29 are not level and that shifts my printing plane.
My printer build plate is steel and I got 4mm inductive sensor.
plate size 300x300mm with 9 points of measurement (extended from 4 because it was same issue)
Here is output of sensor readout from G29 command:
Bed x: 50.00 y: 50.00 z: 4.20
Bed x: 150.00 y: 50.00 z: 4.36
Bed x: 250.00 y: 50.00 z: 4.42
Bed x: 250.00 y: 150.00 z: 3.72
Bed x: 150.00 y: 150.00 z: 3.28
Bed x: 50.00 y: 150.00 z: 3.29
Bed x: 50.00 y: 250.00 z: 2.36
Bed x: 150.00 y: 250.00 z: 2.36
Bed x: 250.00 y: 250.00 z: 2.64
Eqn coefficients: a: 0.00 b: -0.01 d: 4.58
planeNormal x: -0.00 y: 0.01 z: 1.00
echo:endstops hit: Z:2.64
You can notice that measurements on Y=250 are over 1mm away.
I use some magnets to hold the steep plate bed, does that affect sensor readout? I moved most magnets away up to 50mm from sensor stops, to minimalize that effect (if any).
Does anyone had similar issue?