Abstract: A multi-color printing apparatus for screen printing workpieces in diverse colors. The apparatus has a plurality of printing units, each located at a work station, and spaced about a central support. A number of radially extending support arms cantilevered from a rotatable central support carry the workpieces between printing stations. After being indexed to its approximate final position at a particular work station, the support arms engage a brake pad to absorb rotational energy and to control motion of the support arm during a final, precise alignment step wherein a fork member is advanced toward a roller mounted on the support arm to precisely align and lock the support arm during the screen printing operation. Also disclosed is a collar for rotatably mounting the central support at its bottom end. The collar has two portions, one mounted to the central support and the other mounted to a desired location in the printing apparatus.