Save "Z compensation" value  

Save "Z compensation" value

Hi everyone,

I received my assemled i3 mk2 less than 1 week ago. After firmware flashing (1_75mm_MK2-RAMBo13a-E3Dv6full.hex) the printer display was in
Czech Republic language, I am italian and I am in italy! So I googled and make a "soft" reset (that only for language). I did a print with slicer and "optimal" configuration and there was already something suspected about 1st layer height (too height)...but after all she did the print and was pretty fine. After that I tried to do other print but this time 1st layer didn't stick. So after a day of issue and googling I set the 4 corners bed compensation (-0.4) and Z conpensation (-0.5...-0.6...I don't rememer)!

The good thing is I understud that Z compensation help to achive a "perfect" nozzle distance from bed.

The bad thing, and this is why I am writing here for help, is that Z compensation value comes lost after every homing procedure!!

This is what I do:

1- Switch on printer;
2 - variuos calibration stuff...;
3 - printer says it is all ok...no error;
4 - display says Z 0.15 but if I move Z and go to zero I see there is much more than Zero!!!! I think about 0.8 between nozzle and bed;
5 - I go down with Z compensation till I almost touch the bed surface;
6 - Load gcode from sd;
7 - start printing but there is to much distance from bed!
8 (the only way I found for fix this problem) - is the live adjust during printing!! This has no sense becouse when I do the Z live adjut during 1st layer printing, the display show me already the value I set before (point "5")!

CONCLUDING:

I would say that Z compensation value remain not saved! Is this just my problem? I did or I do something wrong?

Slicer offset doesn't work if I write negative value! Is this just my problem?

The firmware does not allow the printer to go under 0.15...sorry but I think this is a stupid choise!

I don't know what to do:

- adjust the probe manually, I mean unscrew and lift it up a bit?

- modify the firmware code and reduce probe offset? I am not expert in this, I downloaded the source code (tar.gz) here https://github.com/prusa3d/Prusa-Firmware/releases/tag/v3.0.10 and still not open it in arduino software. Is possible modify the offset probe with this file? If yes how I load the modified firmware from arduino software into prusa i3 mk2?

- I maybe have to do a fabric reset?

- I maybe wrong the firmware I selected "1_75mm_MK2-RAMBo13a-E3Dv6full.hex" ?

Please help me, thanks!
Manuel