Printer randomly stops and resumes constantly during long prints
Hey guys,
I am lost here. My MK3 prints like a charm since forever, but if it comes to long prints, like 24h+ (dont know the exact threshold), the printer starts to behave funky.
The phenomenon looks like this: The printhead does its job, then, on random positions, no matter if its perimeter or infill, the printing stops, the printhead moves up like 3mm and remains there for like 2 seconds. Then the print proceeds.
And, like one would expect, every time a nasty blob is left on the position the print stopped for no reason. If it was on the infill, no problem, but all to often its on the perimeter and since this happens so often (sometimes several times in one layer!), the outside will look and feel like sandpaper.
What is the cause of this strange behavior? During short prints, this does not happen, but, as I said, during long prints that starts to happen right at the first layer. This problem persisted through firmware updates and slicer versions (I use the Prusa Slicer).
I havent found a pattern where this starts to happen, neither in print length nor in model height, but I guess when the g-code gets big enough, this happens. Does someone know how to fix that?
RE: Printer randomly stops and resumes constantly during long prints
When this happens have you checked the temperature on the screen? Could the nozzle be cooling down and pulls away from the print to get back to temp? Just a guess here, I have a MK2.5s so I have the older board and I don't know all the features available to the MK3, but since most of the issues people have with the MK3 translate directoy to the MK2.5s I participate here.
If it is pulling away to heat up then you could fix it with a silicon sock and PID tuning, or by lowering the cooling fan. If not, well hard to say.
Cheers
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit
RE: Printer randomly stops and resumes constantly during long prints
Ive checked the temp and its stable. However, it also happens that the printer moves into the filament changing position one or two times during a 24 hour print and beeping telling me to unload the filament, then reload it just to continue the print.
There is only one solution that worked so far and that is to turn every senor off, which means "normal mode", fan detection off, filament sensor and crash detection also off. That solves the issue, but what the cause was is still a mystery.
RE: Printer randomly stops and resumes constantly during long prints
Sounds to me like the filament sensor may be having a problem. You might want to take a look at this:
https://help.prusa3d.com/en/article/filament-sensor-mk3-non-s_2125/
Cheers
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit