Motion Index Drives’ TR series headstock / tailstock trunnion sets utilize a high precision (less than 1 arc second) planetary gear system mounted in a vertical position complete with mounting plates. TR series Trunnion Index Drives are ideal for moving large masses with smaller units and minimizing your equipment’s footprint on the floor. All TR series trunnion units can be ordered with standard or custom frames fully equipped with head and tailstock supports and one-piece base weldments.