I incorporated a Pause in my print job, which is printing TPU. I told my P1P to unload, and then walked away from it for awhile. I came back to a cold tip and the “Unloading…” message. No “Retry” button.
(I have a pic of the screen but this site says that I’m not allowed to upload it.)
It’s been on that screen for over 5 minutes, animating the ellipsis (…), but otherwise doing nothing.
If I remove the tool head cover, Bambu Studio will alert me that the tool head cover has fallen off. So, it’s not as if the software is locked up. There’s just no exit path from this UI condition. Which is odd, because I usually get the “Retry” option after it attempts to eject the filament, but I’m not there to pull the filament back.
I think my cutter is worn and failing to cut the filament completely, so it also pulls up the bit in the heat break. In this particular instance, I pulled the filament out by hand, and it looks like a successful cold pull - the tip is pointy.
It might think that there’s something in the filament travel path? I’d like to be able to preheat the hotend, run the extruder, and feed filament into it to see if I can clear it that way. But no, I can’t even preheat the hotend. Since it’s below temp, it won’t move the extruder. My only hope is that if I power cycle the machine, it’ll offer to resume the print.
I removed the heater assembly, and confirmed that there was no filament or debris in the filament travel of the extruder, heat break, or heater block. I then power cycled the printer, which helpfully offered to resume the print, but it had gotten its z position unsynchronized from the print and started printing in the air. Scrap one print.
I guess from now on I’ll need to manually heat the tip and manually command the extruder to change TPU filament. 