On Wednesday, December 22, 2021 4:24:30 AM EST John Dammeyer wrote: > Here's the 140 Tooth cup and 147 Spline for a 20:1 ratio with 0.5 module
That's a rule violation for a two point drive, the count diff must be a power of 2. For a triangular wave with three bearings, a diff of 3 is required to keep the belt centered. I suppose one could use a 90 degree, 4 bearing generator with a 4 tooth diff but haven't tried it. With 140/142, it would a 70/1. ratio. 140/144 would be 35/1 At 140/147, you can see the off center in the much smaller gap at 11, compare to the much larger gap at 5 oclock that you can see. In my experiments I found a 4 count diff very difficult to get right w/o more eccentricity in the wave. Which leads to broken belts even in petg. > gear teeth. No backlash in fact a bit tight. ID of cup is 68.5mm so a bit > smaller than the original one (82mm ID) with the big teeth and 1.25 module > (36:1). > > Only problem is the cup gear layer changes were all in one row and it's made > more of a dip than bump and the bearings do hang up a bit on it. > > Funny thing too. The wave generator disk looked like crap and the bearings > wouldn't fit on their posts with Cura but came out nice with Slic3r. The > cup is Slic3r. The spline done with Cura. > > http://www.autoartisans.com/harmonicdrive/HM_Drive-140T0.5M.jpg > > I'm going to try and reprint the cup with random layer changes to try and > get rid of the bump. Should be able to mount it into the existing box and > lid and try it out. > > John > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > . 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, 1940) 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
