Ult 2 stops extruding randomly

[jdenec123 0]

On pretty much every single print I have done lately on the Ultimaker 2 it stops extruding fairly far into the print. When I look at the filament in the extruder, I can see a huge indent in the filament and the knurled gear is completely covered in plastic shavings. Before the print starts, it extrudes perfectly. And until it stops extruding, the print is perfect. I am using this modified extruder, and has improved, but its still not fixed.

https://www.youmagine.com/designs/alternative-um2-feeder-version-two (thanks |Robert|!)

I am also using 1.75mm PLA. I set the filament diameter to 1.75, so I don't think that is the problem. I am printing at 210 C. Does anyone know what I can do to fix this?