Potential bug after filament change (FW 6.5.3+12780) – Nozzle hitting the bed
Hello everyone,
I've run across a potential bug in firmware version 6.5.3+12780 - Mk4S. After a filament change, it seems the printer loses its position, causing the print head to hit the build plate.
I ignored it at first, rotated the plate, cleaned the nozzle, and everything seemed okay. However, in the middle of the first layer, the print head lowered so much that it stopped extruding filament. This triggered a "clogged nozzle" error. I removed the filament and reloaded it, but afterwards, the head hit the build plate again.
Has anyone else experienced this? Am I doing something wrong, or is this a known bug?
RE: Potential bug after filament change (FW 6.5.3+12780) – Nozzle hitting the bed
I haven't heard anyone complain about this in the last few weeks since that firmware was sent out. I haven't seen it either... but you've seen it twice. So, the most likely explanation is something about your setup is causing this. Are you watching the first layer? Does the print head bind anywhere (you would hear very loud noises). If not, then I think the next most likely thing is the nozzle itself might be too loose - can you push it up and tighten the thumbscrews more? Not enough to crush the tube but it needs to be pretty tight.
My theory is the nozzle is being pushed up during bed probing, but when you go to print it is sliding down and of course will hit the build plate.
Prusa MK4 since Jan 2024, MK4S/MMU3 since Jan 2025, Printables: @MikeB_1505898