Abstract: A projector tilt mechanism includes a base about which a load-carrying platform is rotated in a vertical plane. A threaded shaft is rotatably coupled to the platform by radial thrust bearings and to the base by threaded fittings. Lost motion in the rotational system is avoided by properly positioning and locking in place two threaded nuts along the shaft at either side of the threaded connection to the base, and by using threaded locking collars tightened against the outermost thrust bearing faces. Rotation of the shaft produces relative rotation of the platform and base, causing the base to raise the front or rear of the projector above a flat surface or, if the base is affixed to a pedestal, causing a direct change in platform pitch.