Abstract: A motor assembly useful for rotating a drum comprising: a hub adapted to be removably secured to the drum so that the drum rotates in response to rotation of the hub, the hub including a first outer surface adapted to face toward the drum and a second outer surface adapted to face away from the drum; a motor comprising a spring element having a first end adapted to be secured to the hub and being in aligned position relative to the hub to be wound around the hub between the first and second outer surfaces to apply a force to the hub which force urges the hub to rotate in one direction; and a housing adapted to hold the hub and the motor in aligned position substantially without frictional contact with the first and second outer surfaces of the hub.