Yes, 16 mm bearing can't help. I think what would be best is to use two bearing and make them half the diameter of the inside of the cup. That would be the largest possible size that would still fit.
That said, why not make a large size bearing from a small one by slipping a plastic disk over you 16mm bearing to make it's effective u Once I thought of slipping a disk over a bearing to make the bearing half the diameter of the cup. Then I think "Why can't the diameter of the plastic bearing overlap. Cut groves in each disk? (really now it is a plastic "tire" mounted on a bearing) You might get a "tire" diameter that is 60% of the cup diameter and still use smaller skateboard bearings On Wed, Dec 1, 2021 at 9:37 PM John Dammeyer <jo...@autoartisans.com> wrote: > Broke the first cup. It's possible that a few times I didn't insert it > right because the holes didn't line up well so I might well have begun the > crack which then escalated. If it's inserted off axis it's hard to get it > into position and if it even turns is very rough. Get it right and it's > quite smooth. > > There are several issues. First of all a tiny vertical piece of the root > of the tooth broke off. I think that happened first. Then the pressure of > the bearings sheared the cup along one of the print layers. > > So first weak spot of course the print layers and the plastic probably > never really bonding past a thin line. I used 0.2mm printing. > > My smaller 16mm bearing is also a much higher load point than the larger > ones used in the belt versions. Even if I'd made the full disk with 10 > bearings I don't expect it would have made much of a difference because > they just can't get as close together as a real harmonic drive with ball > bearings which are also distributing the load over the entire outer race. > If anything a larger group of small bearings as close as possible to each > other would more accurately duplicate this. > > www.autoartisans.com/harmonicdrive/HarmonicDrive-11.jpg > > This type of flex cup if not made of metal would be better with a cross > hatch carbon fibre in flexible epoxy. > > John > > > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
