Mornin' fellas!! That is all..... Pete
On Thursday, February 14, 2013, Gene Heskett <[email protected]> wrote: > On Thursday 14 February 2013 04:51:03 Erik Christiansen did opine: > >> On 13.02.13 16:17, Pete Matos wrote: >> > I have actually looked at Mcmaster carr as I usually do but did not >> > see >> > >> > what I needed. I actually like the looks of those cut bodied couplers >> > but I am not too sure of their misalignment ability. A quality >> > oldham in the right size should work fine I think....peace >> >> I've never done any measurements, but figure that the "helical beam", or >> whatever you want to call them, couplings ought to have the lowest >> backlash. An Oldham coupling must wear out, Shirley? >> >> Erik > > I made several sets of these from old mine shafting, about 1.4" in > diameter, quite a few years ago, and installed them between the 225 oz > double stack nema 23's on my toy mill, and the OEM 20 tpi square screws, > nearly a decade ago. My miss-alignments are on the order of 1/32", and I > slobber a little vactra on them when I think about it. They went together > originally with perhaps 2 thousandths of an inch between the tenons and > fins, and may have worn an additional thousandth since. The are not > shielded from dust and swarf. With the motors running micro stepped at /8, > screw reversals can still be felt within 2 steps of a reversal command. > The piss poor nuts (and I'm being kind with that description) it uses are a > far larger source of backlash than these couplings will ever be. I may > eventually put ball screws in the thing, but my inclination is to get a > bigger, much more beefy machine, this toy has far too many design > compromises I fight with daily, like the extremely short and easily bound > up Z ways. Not helped a bit by a tiny post like a willow tree branch. > > 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> is up! > My views > <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> > You will stop at nothing to reach your objective, but only because your > brakes are defective. > I was taught to respect my elders, but its getting > harder and harder to find any... > > ------------------------------------------------------------------------------ > Free Next-Gen Firewall Hardware Offer > Buy your Sophos next-gen firewall before the end March 2013 > and get the hardware for free! Learn more. > http://p.sf.net/sfu/sophos-d2d-feb > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
