You can now build linear slides with our Actobotic beams and gear racks! The 32 pitch gear racks attach directly to our 11.935” beams, but can easily be cut-down to work with shorter beams. Perfect for steering rack systems or building your own linear actuator. When used in conjunction with beam brackets S, T or U the possibilities are endless. Made from durable Delrin.
http://www.servocity.com/html/beam_gear_racks.html