Abstract: An improved drive system for driving one unit of a printing press includes first and second meshing gears which are fixedly connected with blanket cylinders of the printing unit. Third and fourth gears are driven by the associated blanket cylinder gears and are connected with the plate cylinders of the printing unit through harmonic drive units. To tend to minimize backlash and enable the blanket cylinders to be thrown off while maintaining the gears in meshing engagement, the plate and blanket cylinder gears have design pitch circles which intersect. The harmonic drive units have internal gears which, during operation of the printing press, are effective to rotate the plate cylinders relative to the plate cylinder gears. To enable the plate and blanket cylinders to be driven at the same surface speed, it is necessary to offset or compensate for the effect of the gears in the harmonic drive units.