A knockout drive system for a food patty molding machine includes an electric motor; a rotary-to-linear motion converting apparatus operatively connected to the electric motor; and at least one knockout member operatively connected between the rotary-to-linear motion converting apparatus and the knockout plungers, to reciprocate the knockout plungers. The mold plate and knockout plungers are not mechanically linked to be driven together but are independently driven. The electric motor of the knockout drive system is a servo driven motor wherein the speed, acceleration, deceleration and dwell periods of the knockout plungers can be precisely controlled to be synchronized with the mold plate movements and positions, and for the type of food product, the output rate and the shape of the patties.