I was printing on my Taz4 last night when the filament (LulzBot PLA) stopped extruding. The extruder turns, and when I looked at the filament it was ground down at the hobbed bolt.
Tonight I removed the nozzle (following the instructions in the manual). The nozzle was clear. I tried heating it up to 190 and tried to push the filament though (with the nozzle still off). I let it heat for 20 min and tried pushing again and it sill did not move. Finally I tried heating it to 200 and tried pushing again. Still nothing.
Not entirely sure where to go from here. Any advice would be appreciated.