I have had my Lulzbot Mini for a couple of weeks now and have been printing almost every day with ABS filament. Today it stopped in the middle of a 2 hour print. A test extrusion failed to extrude filament. Removing the filament revealed that the filament had a gouge in it made by the hobbed bolt. I cleaned the hobbed bolt and the print nozzle and tried again several times to get the filament to feed, getting the same results – the hobbed bolt would gouge the filament and stop feeding.
I noted that a few other posts noted problems like this with two possibilities: heat creep and idler screw adjustment. I ruled out heat creep because that is supposedly a problem with PLA only and the worn part of the filament wasn’t warm whenever I removed it. Another post stated that the separation between the washers on the idler screws should be about 5 mm. Though the distance appeared to be about 5 mm, I tightened them to be a little less than 5 mm and this seems to have cured the problem for now.
I thought I would share this information in case anyone out there sees the same problem and, heaven forbid, if my feed problems should return.