Abstract: A cutting apparatus with two cooperating rotatable cutting knives is driven by a driving shaft rotating at a constant speed and includes a speed controller in the form of an interlocking rotatable pin and slot drive connection, the input and output shafts of that connection offset from each other, and acceleration and deceleration compensating means including a compensating flywheel and an interlocking rotatable pin and slot drive connection having the input and output shafts offset from each other, the input shafts of both slot drive connections being coupled to the driving shaft, the output shafts of both of the connections being held against bodily movement while the input shafts are mounted for parallel bodily displacement, and means for adjusting the position of the input shafts of the slot drives. Preferably, the input shafts have a common axis of rotation.