I am working on a modified OX with a belt drive rack and pinion system. It is really a modified F-117 and uses 80/20 5010 beams for the X and Y. Preliminary design gives a 6" Z with 50"x50" travel for the other axes. I am using cncrouterparts pro racks and made up belt drives. The cncrouterparts drives are just a bit to big to easily use in this design. See attached pics, comments welcome.
If the pre-made units are too big, make your own. It is really not that difficult. Ref: http://www.openbuilds.com/threads/ox-speed-reduction.1158/ (The reference is based on a belted ox but with a few minor modifications including adding a pivot and spring, it is easily morphed into an R&P unit.)
This design includes new design belt drives, I did see your design in another thread. I tried to keep it simple, and it sort of is, yet I included a pair of roller thrust bearings on the large pulley. The purple and blue plates are 1/4" machined plates but there is no pocketing on them, just straight holes.
