@Veti I use 6 calibration factors (13pts), here is my bed.g: 0_1550510388221_bed.g
@dc42 The circular spirit level on top of the effector gives me of course the reference to the ground, but the positioning of the bubble is pretty centered and is consistent moving it across the bed. Given I placed it above the metal casing of the fans (40mm above the rod axes), the error should be even amplified, so should be ok...
That said, I’d expect that given that the glass bed is flat (measured with a precision square), the bed compensation should do the on-the fly corrections as the print is being executed, according to the poor mesh… instead it looks like it’s ineffective since it looks like the mesh just keeps the Zmax deviation (0.3mm) as the Z=0.
I've proven this to myself by manually jogging to Z=0, measuring -0.3mm of bed distance and then adding it to the M665 height along with disabling M501 in config.g, but keeping M375.
In lack of ideas, I even tried rotating the bed… but got roughly the same results, so one might say it could be the top frame extrusions on which the bed is directly laying (even though the whole frame is truly squared and measured with precision workshop tools), but again, if I put a flat surface on top of the frame extrusions, and given the bed is not being bent by any clamp (as it’s only firmly kept on the sides by plastic mounts), I'd expect the bed compensation should dynamically correct the print… or am I missing something?
Here is also my config-override.g, being loaded by M501 at the end of config.g:
Issue is I just can't get that perfect 1st layer... and it's driving me nuts
Thanks for any help/suggestion.