A self cleaning cutting assembly is provided, having an array of counter rotating cutters in which a plurality of cutters rotating in a first direction are mounted on a first shaft and a plurality of second cutters are mounted on a second shaft for rotating in an opposite direction. The array of cutters is provided with a plurality of clearing or cleaning rings located alternately with the cutters on each shaft. The cutting array is kept clear of debris or partially cut material by movement of the clearing or cutting rings against adjacent cutters. Movement of the clearing or cleaning rings is a combination of rotary motion and linear motion, in which the linear motion is imparted by the cutter located opposite the cleaning ring striking the cleaning rings so as to push the cleaning ring beyond the position of the widest part of the cutter to completely dislodge material from the cutter.