I think most of you are failing to realize the kind of lathe the OP is talking about. The Sherline is a very tiny desktop lathe. The leadscrews are probably 1/4" acme threaded. No ball screws in sight.
Here is a description of the newer version of his lathe: https://www.sherline.com/product/8400/#compare-lathes -- Ralph ________________________________________ From: Gregg Eshelman via Emc-users [[email protected]] Sent: Sunday, November 10, 2019 8:21 PM To: Enhanced Machine Controller (EMC) Cc: Gregg Eshelman Subject: Re: [Emc-users] Axes Names, Backlash and Overshoot Some ballscrews have every other ball slightly undersized so only half the balls are taking any load. If there's enough wear, replacing the "spacer" balls with ones the same size as the load bearing ones can take up the slack, and increase the load capability of the screw. In some cases one or two balls may need to be removed to make room. I've seen some screw rebuilders selling sets of bearing balls in a wide range of diameters for the DIYer who wants to find the best size to take up the wear. Problem is that won't help with a screw that's unevenly worn. You have to make it run right at the ends where wear is the least, but it'll still be loose in the middle. Some screw rebuilders will grind the screw to precise dimension the full length then replace the balls with whatever larger diameter works best. Having that done can make a rolled screw as precise as a ground screw, because it will be a ground screw. Last I looked into that (some years ago) I saw companies offering that service as low as $40. On Sunday, November 10, 2019, 4:34:26 AM MST, Gene Heskett <[email protected]> wrote: On Saturday 09 November 2019 21:44:20 Thomas D. Dean wrote: > I measured several rotations of the Z-axis lead screw on my Sherline > 4400 CNC lathe. > > The BACKLASH setting is 0.0035 Thats bordering on looking to see if it can be tightened up. Start by checking the screws end play. I've added reynolds wrap between the outer races of thrust bearing assemblies and their seats in the bearing housings in brand new screws. Might have to replace the balls with oversized balls, or figure out how to add ball thrust washers, I've done both. _______________________________________________ Emc-users mailing list [email protected] https://nam05.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=02%7C01%7Cralph.stirling%40wallawalla.edu%7Cc310f0fb0a094a4a3ebc08d7665eb721%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637090429303842556&sdata=Fgb623nKPS3uDjohiSZCjKuFZuRUWvOnU7BhmQNXqlE%3D&reserved=0 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
