Rack and poinion can be very accurate if done correctly. You just need to gear it down to get the required resolution, and use some method of keeping the pinion tight to the rack.
Rotating the nut will work great if you can fabricate all the necessary parts to make it work. Our $100K plus router/machining center uses a rotating nut on a 12' screw.
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Gerry
Mach3 2010 Screenset
http://home.comcast.net/~cncwoodworker/2010.html
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management) |