It is used for feeding and orienting small identical parts, particularly in automatic assembly operations. The motions of parts are channeled in a random pile so that each part automatically assumes a specified orientation, where the symmetries of a part define its possible orientations. The motion of the can be imparted through vibration, gravity, centrifugal force, tumbling, or air pressure. In a vibratory bowl feeder, the most versatile type of parts feeder, parts are dumped into a bowl and then move vibrate uphill along a track towards an outlet, where rejected parts fall off the track and are recycled. Parts feeders can be used to provide inspection capabilities with respect to the shape and weight of parts e.g., the coin feeder of a vending machine. Basically this machine orients parts as they arrive on the left-hand conveyor belt.