an apparatus is described herein which when used in conjunction with a continuous film duplicator or printer , stores and transports micrographic , motion picture , and other masters during the printing cycle to eliminate rewinding when making multiple duplicate copies . the apparatus is modular utilizing a pair of carriages so that it may be expanded either horizontally or vertically to accommodate more footage . a single motor is employed to adjust the spacing between top and bottom roller sets disposed on the carriages for various lengths of film while a three - position sensor arm controls the motor . a slack sensor controls the speed of rollers mounted on shafts on the carriages and a motor drives each shaft controlled by the sensor . low - mass plastic film rollers equipped with soft - touch rubber surfaces are employed for transporting the film and low inertia pm motors provide high acceleration and torque for driving the shafts . a transparent enclosure houses the above mechanisms and film that travels through the enclosure and suitable electronic circuitry is provided for sensing , driving , and controlling the various functions while operating at speeds up to and exceeding 1500 ft / min .