The Feed Controller provides introduces coarse sample material into the Cyclone Sample Mill. A 30 to 40 gram sample is poured into the hopper and is immediately conveyed (by a rotating screw) into the mill. Larger quantities (several pounds) may be handled by using a poly bag in place of the regular sample bottle. A 1" diameter screw is driven by a constant speed gearmotor. The switch has both a forward and reverse rotation control and a neutral or "off" position. Feed rate is 3 grams per second. The Feed Controller is designed to fit on all UDY Mills. It can be mounted or removed readily without tools.