On Friday 11 December 2009, Erik Christiansen wrote: >On Thu, Dec 10, 2009 at 01:10:50PM -0500, Gene Heskett wrote: >> Heck, I knew I wasn't inventing anything that wasn't just common sense, >> but my way leaves room in the middle for the nuts that attach it to the >> screws in the mill, and my center disk has the fins rather than slots. >> All carved from some very hard steel mine shafting from the scrap yard. >> I didn't count on its hardness though, they were hell on carbide to carve >> out. OTOH, I both didn't look at wikipedia, but wouldn't have known what >> to look for either. Such is life. :) > >Ah, if the sense was _that_ common, the rest of us wouldn't need to know >the name of the thing so we can look up how to make it. ;-)
Chuckle. ;-) And 100% correct. That idea was, AFAIAC and knew at the time, 100% whole cloth from this old farts brain. And overkill size wise. About a pound of steel in each assembly. I didn't want to have to make stronger ones later. :) >> >One idea I'm considering is driving via a toothed belt, from a motor >> >clamped nearby, in the T-slots. Just looping the belt over a pulley >> >added behind the rotary table handwheel allows it to still be used >> >manually, when it isn't worth mucking with gcode. >> >> Belt tightness I found is very important as I'm belt driving my Z and >> found I had to wedge a good sized bar in there when tightening the motor >> mounts slider to get the backlash down. With visible belt slop as it >> reverses, the backlash went from 3 thou to 50 thou! > >Oh-Oh, I'll have to remember that. I hope the 50 thou was before the >persuader was used to rack up the belt tension. > Yes, it was what I got when just pushed over by hand & tightened. OTOH, it you look at the pix & see where the motor is, hand tightening that isn't very practical. 2/3rds of the motor is buried behind the alu blocks the Z nut turns in. Operative description is 'crowded'. But Jack Benny could play that belt now. I also had to not only drive the setscrews in the small pulley about 20 thou into the motors shaft flat (the proverbial 1/8 turn from stripped or broken), I had to superglue it too, those 425's can really turn the house around. >Erik > -- 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) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> In general, they do what you want, unless you want consistency. -- Larry Wall in the perl man page ------------------------------------------------------------------------------ Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
