On Monday 12 April 2021 14:55:18 Ralph Stirling wrote: > Thrust bearings at the ball screw ends perhaps? > You may want to read it again Ralph, the screw is fixed, with a rotating nut.
I had one like that I built once. I think Todd is correct and the screw needs to go to a rebuilder. With the nut still on it because they may have to work on both. My $0.02 of coarse. > -- Ralph > ________________________________________ > From: Todd Zuercher [to...@pgrahamdunn.com] > Sent: Monday, April 12, 2021 7:48 AM > To: Enhanced Machine Controller (EMC) > Subject: [Emc-users] Worn Ball Screw? > > CAUTION: This email originated from outside the Walla Walla University > email system. > > > Those here who have had to deal with a worn out ball screw. How is > this normally manifested. I have a machine that is only showing > backlash under load. Is that normally how a worn out screw shows it's > age? I was expecting it to be normal loose backlash that you can > measure. But this is showing up as springy softness that you have to > give a pretty hard shove against to move the dial indicator, then it > snaps back to zero when you let go. Using the usual jogging methods > to read backlash, the machine reads zero backlash and positions well. > But dynamically it is awful, with loud clucking noises on direction > changes and horribly wavy marks left on the pieces milled at those > changes. Giving a shove on the table, I can measure more than > +/-0.01" of this "springy" backlash, but moving the screw to a > normally unused position I can only measure about 0.001". This is a > big fixed screw (about 2" diameter and more than 14ft long) with > rotating nut, is there any hope of fixing it? I'm considering trying > to send the screw out to one of those screw refurbishing places. The > machine manufacturer quoted us over $18,000 to replace it. > > Todd Zuercher > P. Graham Dunn > Inc.<https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2F >www.pgrahamdunn.com%2Findex.php&data=04%7C01%7Cralph.stirling%40wal >lawalla.edu%7C58338609df8b45b6914308d8fde00b00%7Cd958f048e43142779c8deb >fb75e7aa64%7C0%7C0%7C637538485997249904%7CUnknown%7CTWFpbGZsb3d8eyJWIjo >iMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000& >sdata=Ld9xm92SAMAjLkMiiIF8IUVaEr%2FNPwfF0CkiXtceb3E%3D&reserved=0> > 630 Henry Street > Dalton, Ohio 44618 > Phone: (330)828-2105ext. 2031 > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flist >s.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=04%7C01%7Cral >ph.stirling%40wallawalla.edu%7C58338609df8b45b6914308d8fde00b00%7Cd958f >048e43142779c8debfb75e7aa64%7C0%7C0%7C637538485997249904%7CUnknown%7CTW >FpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6M >n0%3D%7C1000&sdata=IkA489PPWpVFBGtsJze2eyUhLWfAKYR3Lw2k0frRhLc%3D&a >mp;reserved=0 > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
