A supply cartridge including a photosensitive drum, a charge roller, a developer roller, and a supply of toner, is inserted into a conventional electrophotographic (EP) machine in operative association with the gear train for such machine. One end of a shaft passing through one end cap of the photosensitive drum is inserted into a receptacle in the EP machine. The free end of a drive transmitting member on the opposite end of the drum engages the drive train, and is driven by the gear train. The drive transmitting member is an integral part of a molded end cap inserted into the open end of the photosensitive drum. The drive transmitting member may assume diverse forms. The upper surface of the drive transmitting member may be triangular in shape, while the base may be circular or triangular; tapered sidewalls extend between the upper surface and the base, and the area of the upper surface exceeds the area of the base to maximize contact with the drive train. The drive transmitting member may assume the form of three, or more, spaced fingers, which approximate the apices of a triangle. The upper surface and the base of the drive transmitting member are in straight line alignment to facilitate molding procedures while maintaining tight tolerances.