I keep running into a strange issue in that once in a while my printer will just stop printing. 99% of the time this is never an issue…yet some how an once in a while it happens and utterly ruins an other wise perfectly fine print. The feed speed is unchanged from print to print. Checked every thing for fouling and found no issues. Any ideas as to what can cause this?

Hi @Nathaniel_Nate,

May I ask you which printer are you using?

Federico - 3D Hubs

Your extruder is getting jammed. Do a cold pull to clear out debris(Clog - RepRap). Are you using any kind of dust catcher on the filament? If not, then you should.
Also, you might want to add a heat sink or fan to the extruder motor. When it gets hot, the metal gear touching the filament also gets hot, which can soften/deform materials like PLA way before they get to the hotend.

-Jesse

There are a few things that can cause “grinding”. Take a look at the Print Quality Troubleshooting Guide. There are a few suggestions there.