Isthmus has incorporated two different types of rack and pinion systems into recent projects. One technology includes a roller pinion system for high-accuracy linear positioning. The rolling element bearings allow for rolling contact engagement with the rack, for high payload carrying capacity without backlash.  The system allows for calculated increments of load/unload positions, replacing the need to program independent servo positions.   The system also allows for high linear speeds with very good positional accuracy, and can be operated lubrication-free at moderate speeds.  The low friction of the system naturally reduces wear and extends service life. Another technology incorporates a straight-tooth rack and pinion drive on a heavy-duty gantry.  Both the drive and gantry were designed and built in-house.   This system features an extremely robust design, and can accommodate long lengths of linear travel (95 ft. in the example pictured here).  The system operates with three independently controlled carriages, carrying hundreds of pounds of payload.