JerryFlyGuy, Jerry you wrote:
...the rack that I'm planning on using has a length tolerance of +/- 0.003 so in the entire length of my unit the movement may be out as much as 0.018"[w/ 3 pc's of rack], this is acceptable. I would actually be happy with 1/32" accuracy, but in the thousands [+/-0.005 ish] in repeatablility. Also the rack/pinion connection is placed under load to maintain as close a mate as is possible, I've been told that a person can obtain as tight as basically a 0 backlash system.
Could you share the sources for that gear/rack combination, prices and part numbers too? Seems like a VERY good approach -- and you have some VERY long axes to deal with. Hmmm maybe the ol Shopbot wasn't such a bad idea... I've been intregued by the rack and gear approach some time and now with those numbers there may be a rush to that approach. Thanks, and
:cheers: Jim
Experience is the BEST Teacher. Is that why it usually arrives in a shower of sparks, flash of light, loud bang, a cloud of smoke, AND -- a BILL to pay? You usually get it -- just after you need it.