On Thursday 25 March 2010, Mark Wendt (Contractor) wrote: >At 11:56 AM 3/25/2010, you wrote: >>At 165 pounds, it may be that the gantry is actually taking up some >> backlash as its stopping from the longer moves which would be faster. >> Can you, as its hooked up & the motors enabled, induce a motion visible >> on the indicator by manually pushing or pulling it? And, equally >> important, does this 'slack' remain constant as you move it with the >> motors? If constant, then perhaps adding some backlash comp might help >> (but that's only effective for motion reversals of course), or if its >> position related, it might be possible to map the screws error. Wear >> patterns can be elusive, and mapping a cyclic error can be 'fun' for some >> definitions of fun. If you have many hours on the machine doing the same >> cuts over and over it might even be advisable to replace the screws. Or >> if the cutting dust can get to them, a really good cleaning might help. > >I'll give it a try manually moving the machine while the motion >control system is up and running. Haven't tried that as of >yet. It's a brand, spankin' new machine that has not cut anything >yet, so if there's wear patterns anywhere, it'll be on my forehead >where I've been rubbing in consternation... ;-) > ROTFLMAO!
>> > I disconnected the pinion gears from the racks, moved the gantry >> >back and forth the length of the X axis a few times by hand, and >> >didn't really notice any binding. It seemed pretty smooth, and >> >relatively easy to move a 165 lb gantry on the rails. >> >>Pinion gears, same thoughts about cleaning apply. I assume they are >>preloaded? > >Pinions are preloaded. Here's the R&P >setup: ><http://www.cncrouterparts.com/product_info.php?cPath=21&products_id=50> > Cool. I'd have reservations about sub thou accuracy with it. Straight cut rack & pinions will have some cyclic errors, repeatable on a tooth per basis, but that has already been said. >>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) >> >>All that glitters has a high refractive index. > >Mark > > >--------------------------------------------------------------------------- >--- Download Intel® Parallel Studio Eval >Try the new software tools for yourself. Speed compiling, find bugs >proactively, and fine-tune applications for parallel performance. >See why Intel Parallel Studio got high marks during beta. >http://p.sf.net/sfu/intel-sw-dev >_______________________________________________ >Emc-users mailing list >[email protected] >https://lists.sourceforge.net/lists/listinfo/emc-users > -- 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) Once harm has been done, even a fool understands it. -- Homer ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
