On Sunday, January 08, 2012 02:49:34 PM andy pugh did opine: > On 8 January 2012 14:02, gene heskett <ghesk...@wdtv.com> wrote: > > Because the coupling is replacing the > > handwheel, its placement controls the end play of the worm too > > I still am not sure which rotary he was on about, but as the title > refers to encoders, and I started that thread with a video of my > rotary drawing an encoder in pen, I think it might have been mine. > > I decided that the original bearing and endfloat arrangement was too > crude for a motor drive, so if you look at the pictures I posted, I > re-made the whole eccentric housing, with a pair of angular contact > bearings for end-float (it has to take cutting forces when moving, > after all) and a needle roller to hold the worm in mesh.
I definitely need to do something similar, Andy. The xy tables screw bearing hubs I long since added some teeny little ball bearing thrust washers to (the screws are 20 tpi acme's), which helped a lot, but no great radial forces exist there so I haven't felt the need to do a needle roller conversion (yet) since the fit there is as yet extremely tight. I drilled into that area and installed a grease fitting, and while I am sure some grease gets into that very low clearance, I have yet to see any evidence of external leakage of that grease, its as if the bottom of the hole is plugged solid when assembled. But that table in the pix on my pages is such a POS, I would be well ahead of the game to start all over with a new, much better table. 6" would be nice, but there is a limit to what those smallish ways can carry too. Eventually, if I live long enough, I'd love to ball screw a BF20. OTOH, I'm 77 & my crystal ball fell off the bench and broke years ago. :) Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> Robert Tappen Morris, Jr., got six months in jail for crashing 10% of the computers that Bill Gates made $100 million crashing last weekend. ------------------------------------------------------------------------------ Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex infrastructure or vast IT resources to deliver seamless, secure access to virtual desktops. With this all-in-one solution, easily deploy virtual desktops for less than the cost of PCs and save 60% on VDI infrastructure costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
