This set of 3d printed Plates allow a stepper motor & 2 pulley mounting plates to be fitted to a length of v-slot rail to produce a drive unit. The stepper plate and the pulley mounts each fix to the rail with two M5 screws. The pulley mounts each have a 16mm hole which accepts a 16mm ballrace and the stepper mount has four 3mm holes to accept the stepper as shown in the photographs.