Abstract: The invention is a drive mechanism for a rotary vacuum forming multifaced drum to essentially match the surface speed of said drum to the constant speed of a web of film issuing from a film die. The instant invention provides apparatus to continuously vary the rotational speed of a multifaced vacuum forming drum with any number of faces, such that if a web of hot film were extruded at a constant rate, the rotational speed of the drum would vary as required to accept the film at a constant rate to provide an essentially uniform thickness of material on the surface of the drum for thermoforming.