Abstract: A drive puck for use as a component in a demand drive system is disclosed herein in which a film roller is resiliently centered on a rotating drive shaft so that the tension of a film strip carried thereon selectively causes engagement of the film roller with the drive puck. The puck is secured to the drive shaft so as to rotate therewith and is provided with an external tread which projects into a lateral cavity of the film roller so as to engage with the underside of the film roller in response to the resilient centering movement of the film roller.