As anyone looked into the RPS : Roller Pinion System ? In surfing the 'net for a better mouse trap, I found the RPS "rack and pinion" as offered by Nexen (and others). A roller pinion system is a linear drive approach that combines the best features of ball screws, rack and pinion, belt drives and linear motors while eliminating many of their short comings. It sounds like a dream drive system for our OXs and beyond ... Read the write up at http://www.designworldonline.com/roller-pinions-another-way-roll-line for some details (from Nexen). Pricing, although they keep saying it ends up costing less, might be an issue ... who factors in long term repairs, maintenance, etc. anyways ?