On Tuesday 26 January 2021 06:00:46 Sven Wesley wrote: > Den tis 26 jan. 2021 kl 05:47 skrev Sam Sokolik <[email protected]>: > > I am sure the torque is limited - but I feel it might have > > possibility... > > > > https://www.youtube.com/watch?v=QlpkmEEhFqc > > I can totally see that drive on my home made trunnion table! > I can't. I spent a couple months trying to make one that would survive and overnight run with a nema-17 motor spinning it, no load, overnight at 500 rpms. Out of every sort of string I could buy including TPU, which was too soft but still failed by over flexing the the spline cup, either delaminating the walls, or breaking it off at the bottom of the splines, or more regularly, at the junction of the spline wall and the disk connected to the outout shaft. The spline that Sam had in his hands with 6 bearings was the general model but the cup would need to be 2x or more deeper just to absorb the flex without fatiguing the plastic to the eventual failure point. Higher ratios would help because it would reduce the flex with the smaller splines, but if I were to try with that version, the drive disk at the bottom of the cup would be thickness profiled to make that "hinge joint" stronger and the disk thinner.
There is reason those commercial versions make the spline as thin and out of a springy steel. And I don't think you can duplicate it in plastic. Those quick failures are the reason I put a servo motor on the bs-1. 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
