Grinders, of any type, act to reduce large pieces of material into smaller and more evenly sized pieces by shredding them through a screening media. The image to the right details a horizontal grinder's basic process. The raw material, comprised of various sizes and shapes of material, is loaded onto the feeder belt. The feeder belt sends the raw material into the throat of the grinder where it is directed by the downward pressure of the feedwheel against the grinding rotor. The grinding rotor shreds the material until the pieces are small enough to pass through the screening media underneath it. The feeder belt and feedwheel are controlled by sensors to regulate how much material is fed into the grinding rotor to ensure efficient operation and prevent over or under-feed conditions.