I have had the issue of the filament not extruding correctly since I received my printer, but thought I had it mostly fixed...
Last night I started a 20 hour print, things seemed to be going fine until I woke up this morning. Somewhere between 4-8 hours into the print, the filament just quit extruding. Stepper motor was still running, filament was still in the extruder but it was not feeding the filament.
Has anyone else had this issue? I know the usual solutions, pull the stepper off, clean the pully and tighten set-screw. I have done this probably 10 times now.