Have to reduce "Live Adjust Z" for every print
I have had my Mk2 (upgraded to a Mk2S) for years, it has been through a lot but is a phenomenal work horse.
About 1 month ago I noticed the nozzle would be too close to the build plate every time I tried to print something, originally I had a "Live Adjust Z" offset of close to -1000, every print I had to adjust it about +200 to get the nozzle to the right height. (Say it started at -1000, I would have to change it to -800 the next print, -600 the next print etc.). I checked the PINDA, it seemed to work fine, but I ordered a new one and replaced it anyway. I also updated the firmware to 3.2.3 and did a full factory reset of the printer.
After all these changes, it is still happening. It could possibly have started happening around the time I updated to Prusa Slicer 2.1? I have checked the Start and End GCode to see if there is anything that looks like it might be adjusting Z Offset and I can't see anything unusual.
Everything is bolted up tight, nothing is coming loose and slipping closer to the build plate etc, I am at a total loss as to what could possibly be wrong.
Anyone have any ideas?
RE: Have to reduce "Live Adjust Z" for every print
I've run across something similar on a MK3; you must run the embedded Level 1 Calibration at least once before Live-Z becomes sticky (until you do this, the LCD says the value is X when it really is an older stale setting).
And if it isn't that, the other thing is the PINDA is temp sensitive. If doing sequential prints with no cool down, you may need to set Live-Z every run.
RE: Have to reduce "Live Adjust Z" for every print
Thanks for the reply Tim, unfortunately it's neither of these things as far as I can tell. The problem came up out of nowhere after working correctly for over 2 years, then all calibrations have been done again since the firmware update and calibration wipe.
As for the temp sensitivity of the PINDA, this occurs on a hot or cold start, consistently requiring the z offset be increased by 200 every time.