PETG keeps clogging and balling up
I've been printing with ABS for quite a while but the warping has become intolerable so I'm trying to move over to PETG. The quality of the prints for the most part looks fantastic. However, when I do taller objects, the print invariably fails before the print is finished. Sometimes it makes a big balled up mess that it deposits on the print and then runs into on the next layer. At that point it says "crash detected" and sometimes I can cut it off and proceed and sometimes not. Other times it just clogs up completely and just moves through air for the rest of the print with the extruder skipping and nothing coming out. Any tips on how I can make these prints more reliable with this material? Most of the stuff I have read about focuses on getting the first layer right, but I don't think it's that as the first layer looks beautiful and the failures usually don't happen until hours later.
Re: PETG keeps clogging and balling up
Update: After looking closely at a couple of failed prints, it seems like it is most likely to happen when it is transitioning from a layer that is just honeycomb to a layer that has flat surfaces, if that is a helpful clue.
Re: PETG keeps clogging and balling up
PETG can have a tendency to pile up taller than desired when multiple end of layer nozzle raises happen at the same location. You end up with a nub that projects upward. Eventually, this gets caught on the print head and you have this kind of problem. These built-up "nubs" seem to happen at layer transitions when there has been insufficient cooling to get a clean nozzle lift.
The solutions I have found have been to slightly increase print fan% and/or slightly drop nozzle temperature. Increasing fan had the biggest effect.
You may also do better with gyroid fill. That may have fewer nozzle lifts for the same amount of fill.
Re: PETG keeps clogging and balling up
I switched to Gyroid and slowed down the infill speed. It started off ok, but after maybe an inch of height it started stringing a lot and then the extruder started skipping, it completely stopped extruding and that was the end of that. It didn't make a big ball, just clogged and stopped. Thoughts?
Re: PETG keeps clogging and balling up
I think the nozzle is clogged. Higher risk especially if you switched from higher temp ABS to PETG.
I would heat back up to ABS temperatures, run some cleaning filament through to remove possible ABS residues.
Cold pull if needed.
Extruder skipping probably means you have enough clamping force on the extruder idler. If it was grinding the filament when it got clogged, then I would worry about the extruder idler.