Z-axis adjust "drift"?
This is driving me a bit crackers right now. After three months of mostly trouble-free printing (apart from the usual blockages in the hotend, poorly positioned heatbreak, underextrusion etc), over the past week I've had to readjust my Z-axis settings every few hours!
The problem is always in the first layer (the rest of the print will come out fine); I *know* after realigning the hotend last time the Z-axis needs to be set at 770 with the smooth PEI sheet. But a few prints later, it's too close to the plate, leading to the nozzle scraping across the first layer. Fine - adjust it and away we go. Then a few prints later, same problem. Adjust it by another 20-40, and everything's fine. Except over the course of a week I've adjusted by initial Z adjust by over 100. And then all of a sudden that was WAY too high, and to get a perfect first layer it's back to 770.
And this is with me changing NOTHING else. Printing with PLA (although swapping for various colours), onto the smooth PLA sheet. It wasn't doing this to me last month.
Has anyone else experienced this, and what might the fix be? If it was just dropping steadily I could understand it - but to suddenly need to be reset back to the original height is not something I understand.
RE: Z-axis adjust "drift"?
Strange indeed... The only thing that I can imagine could influence Z-offset, is either issue with PINDA or bed heating.
As for PINDA, you can only check if it's properly tightened and if it has good wiring connection. If that's ok, then I would assume PINDA is malfunctioning (running out of tolerances for whatever reason).
Maybe it's also worth to check wiring of bed temperature sensor -if not good, this can lead to incorrect bed heating which again could influence first layer calibration.
Just sharing my thoughts
[Mini+] [MK3S+BEAR]