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
