Did you try PGM Reball (saw them on an old video I have)
On Tue, 13 Apr 2021 at 14:38, Todd Zuercher <to...@pgrahamdunn.com> wrote: > Yes, near the limit switch, outside of the normal travel area, I can not > measure any backlash. That pretty much points the finger squarely at wear > on the screw as the main culprit. I think I have figured out the "springy" > backlash uptake mystery. It is simply the weight of the screw sagging down > and resting on the nut pushing the table to the center of the ball grooves > (remember the screw is more than 14ft long.) > > Anyone know of any good ball-screw refitters in the States? I already > checked with one and they didn't want to touch it. > > Todd Zuercher > P. Graham Dunn Inc. > 630 Henry Street > Dalton, Ohio 44618 > Phone: (330)828-2105ext. 2031 > > -----Original Message----- > From: Stuart Stevenson <stus...@gmail.com> > Sent: Monday, April 12, 2021 11:12 PM > To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] Worn Ball Screw? > > [EXTERNAL EMAIL] Be sure links are safe. > > Plus or minus .010 is an amazing amount. Also, you mentioned another area > on the screw you saw .001 lost motion. This leads to a screw problem. > I would do what Jon Elson says as this sounds strange but I would expect > to find screw wear. If it was nut wear the backlash in all areas of the > screw would be close to equal. Not knowing the drive train maybe there is a > gear train and one area of the gear train has worn teeth and where you > found almost no lost motion is where the gear train is the best. > Expect screw wear but hope for a gear train problem. > HTH > Stuart > > On Mon, Apr 12, 2021 at 5:15 PM Jon Elson <el...@pico-systems.com> wrote: > > > On 04/12/2021 09:48 AM, Todd Zuercher wrote: > > > Those here who have had to deal with a worn out ball screw. > > I'd dig into the works and examine everything. It does NOT sound like > > simple wear. > > The rotating nut likely runs in a pair of either angular-contact > > bearings or tapered roller bearings. There will be a preloading > > arrangement to constrain the nut. Also, the screw is usually fixed at > > both ends. If the clamp has gotten loose at one or both ends, it > > could allow some flex of the mount under load. Attach a dial test > > indicator to the slide and read against the end of the screw, and > > watch for movement when you apply load. > > > > Some old ballnuts were actually TWO completely separate nuts that were > > preloaded against each other with Belleville washers. It is possible > > some of the Bellevilles have cracked. > > Also, they often used dowel pins to align the two nuts rotationally. > > If one of the dowels has cracked, that could cause this kind of issue. > > > > Jon > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > -- > Addressee is the intended audience. > If you are not the addressee then my consent is not given for you to read > this email furthermore it is my wish you would close this without saving or > reading, and cease and desist from saving or opening my private > correspondence. > Thank you for honoring my wish. > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
