bobstro wrote: ↑
Aug 02, 2018 1:45 pm
simone.f wrote: ↑
Aug 02, 2018 12:33 pm
[...] Could it be because the room is too hot?
The printer is in a enclosure. Well, actually the enclosure door is open, but in the room, there are more or less 30-31°C, it's hot!
Heat will certainly add to the heat problems! A lot of the recent posts coincide with the hot summer months and/or enclosure use. Prusa has issued an extruder design that is intended to improve cooling, but even that will have limits. An open enclosure door might not be enough to allow airflow. You could try adding cooling or printing the new extruder parts, but it does sound like using another filament will work for you.
The fails seem to happen most frequently at detail areas with lots of retractions. Retractions add to the extruder motor works, which generates heat, which can creep into the extruder mechanism. You could try minimizing the retractions or slowing down if you are using the default Prusa speeds for infill.
I've downgraded all speeds to 40mm/s as descrived in product specs.
Initially I was thinking the problem was at the teflon tube heigth, but, looking the filament near, I've noticed the hobb-goblin have marked the filament for approx 7,5cm, it means, the filament was pushed down until the extruder. The UNLOAD is not working, maybe, because, as soon the end of the filament reaches the hobb-goblin during unload, it doesn't pass through. So I need to open the right side, cut the filament, remove it and then I'm able to unload it.
I've noticed in addiction that during the print, as soon the extruder stops to extrude, the nema motor step which pushes the filament down, seems is jumping steps, like it's skipping or sliding on the filament...
Maybe always a temperature problem?
The extruder is clean, because other filament works!