Hello all,
I have had Prusa MINI for a few years already and I have printed PLA without an issue but recently I have printed only PETG for some time I got through multiple spools of PETG without any print in PLA. But after I tried to print PLA my extruder kept skipping and grinding filament and when I tried to feed filament by hand it went easy for a little bit but after that, it went very hard as if the filament was cold so I tried to bump up the temperature to 235C and it helped a little bit but on faster sections of print like the infill extruder is skipping again. I don't think I have unreasonable speeds i am using a standard Prusament PLA profile with Prusament PLA. I have also tried PLA+ from some different brand with the same result. Then I changed the nozzle from an E3D hardened steel nozzle with nano coating to brass (not new I have printed PETG on this one as well) still with the same result. PETG is printing fine. Is there something I can try, please? I am out of options.
My best guess would be that you have some petg left in the nozzle that for whatever reason isn't being melted and pushed out, what you could try is doing a cold pull
If you haven't done it before, you basically heat up the hotend, feed in some plastic, then you turn off the heat and let it cool down until the plastic is partially hardened, then you yank on the filament
If everything goes right, the plastic down in the nozzle will be yanked out, and pull with it any impurities, leaving the nozzle clean and unclogged
Alternatively buy a new nozzle that you only use for PLA, i have heard a lot of people having issues like this when switching back and forth with the same nozzle