Abstract: An improved control apparatus that automatically maintains line balance and prevents part jam up in a manufacturing process by selectively removing parts from a conveyor line coupling successive manufacturing stations. The apparatus includes a stationary proximity sensor and air knife mounted with respect to the conveyor line, a timer, a solenoid-operated air valve for coupling the air knife to a source of compressed air, and an excess part bin adjacent the conveyor line. When the proximity sensor is closed for more than a first predetermined interval, an impending jam-up of parts is detected, and the timer activates the solenoid-operated air valve for a second predetermined interval, causing the air knife to blow one or more parts from the conveyor line into the excess parts bin. A manually operated switch may be provided for continually activating the air valve to remove all parts during maintenance operations.