Latest Mars Firmware Release - V4.2.19_LCDM /1440x2560 /F2.7

[Hywel]

I hear a grinding noise


I presume you reset the Z offset on redoing home? Firmware will have wiped it.

I thought Z offset was set by doing the home the plate method (with a piece of paper) no?  On the regular Mars you cant manually set Z=0??

Sorry for being dense here...
Thanks



you’re not being dense lol. I’m pretty new to mars too, but 4 years on fdm. It’s a classic with those that you need to reset ‘home’ when you upgrade firmware. So try that and see if the grinding has gone. 

Ah!  Well I did do that - multiple times now to level the build plate on 1, 2 and 3 pieces of paper.  It always levels/homes perfectly, but then when I print it does this wierd grind thing.  Just to make this extra weird, it only happens on SOME prints, not all.  I thought it was an issue with the new Chitubox slicer and went back to my older version but that was a red herring it'd seem.  Thanks for the suggestions!