On Sat, Jun 06, 2009 at 08:44:57AM -0400, John Kasunich wrote: > > My shoptask (cheap chinese lathe-mill-drill) had horrible backlash in > the rack and pinion quill drive. There was lash in the rack-pinion > itself, lash in the dog clutch that connected the pinion to a worm gear > (disengaged for manual feed), lash in the worm gear, and axial play in > the worm mounting. The total was about 0.050 to 0.060 inches.
While I only have 0.008" to deal with, a possible fix presented itself on an old motor assembly from the junkbox. It has a split pinion, which drives a wide nylon gear. The two pinion halves seem to be slightly out of phase, thus loading the (1.2" thick x 7" diameter) plastic gear, removing backlash. (It's from a 6' x 4' high speed plotter. The 8" diameter motor flung the 4' long carriage the length of the bed in a fraction of a second, with precise placement. There was no discernible backlash.) It might be possible to do the same with the quill rack. It would need a small amount of tooth mesh adjustment, though. And that's not looking practical. ... > A sectioned drawing is on this page: > > http://jmkasunich.com/cgi-bin/blosxom/shoptask/Z-axis-12-16-06.html Thanks, that's very useful. I hadn't thought of making the yoke in two parts, but it saves wrecking the allen key while while trying to close up the hole in a thick plate, especially at the small end. Erik ------------------------------------------------------------------------------ OpenSolaris 2009.06 is a cutting edge operating system for enterprises looking to deploy the next generation of Solaris that includes the latest innovations from Sun and the OpenSource community. Download a copy and enjoy capabilities such as Networking, Storage and Virtualization. Go to: http://p.sf.net/sfu/opensolaris-get _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
