On Wednesday 14 April 2021 12:15:11 Chris Albertson wrote: > On Wed, Apr 14, 2021 at 8:54 AM Thomas J Powderly <tjt...@gmail.com> wrote: > > A few of the larger EDMs we built had 5meter leadscrews with dbl > > nuts, > > That would fix the issue too. They use two nuts with a spring > between them. It is really the same concept as oversized balls. In > both cases, the balls ride on the walls of the groove rather than the > groove's bottom. > > Some day 100 years from now the ball screw on my mill z-axis might > become worn but the screw is always in tension as it supports the > weight of the milling head and motor so the balls ride on only the > lower side of the groove and it will not matter much if the balls or > groove is worn down over the years. My 3D printer works the same way > but with acme lead screws, only one side of the screw thread Is used, > so there is never backlash when the direction of motion reverses.
I would not put much money on that, I've put a considerable amount of time in getting an ender 3 to that state, they come with the rollers too tight to allow gravity to have its way and in my case I also had to loosen the right carriage roller plate from the bar after adding a wee bit of tension on the rollers, loosen the bottom screws in the uprights, ran the head down to help locate the uprights, tighten the upright screws again, then the right roller plate to bar screws, then lift it to the top and repeat the screw loosening and retightening to the top screws. Much free-er feeling motion as the result. And a bit of screw goo on the screw helps. Powered off, just another ounce or two on the x bar should make it fall. 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
