I just did t quick Google and found several companies who make belts "sliced to order" in any width. 6" wide if you like
The other way to "print" a flex cup is the print a female mold and fill the mold with urethane and kevlar fiber. I'm working on a robotic/prosthetic hand that uses this technique, Many of the parts are made with a very strong kind of urethane. This stuff really takes a beating. This is really a good way to use a 3D printer, You can make multi-part molds that come apart to allow the molded parts to be removed. On Tue, Jan 26, 2021 at 12:13 PM Todd Zuercher <to...@pgrahamdunn.com> wrote: > For the belt idea, it might work better to invert the whole thing, So you > have the belt teeth in and one gear with two fewer teeth than the belt, > then the follower wheels on the outside of the belt compressing it to mesh > with the smaller gear. The hardest part might be finding a belt wide > enough to reliably flex between the two gear diameters. (Something tells > me this sounds better than it can actually work in practice.) > > Todd Zuercher > P. Graham Dunn Inc. > 630 Henry Street > Dalton, Ohio 44618 > Phone: (330)828-2105ext. 2031 > > -----Original Message----- > From: Sam Sokolik <samco...@gmail.com> > Sent: Tuesday, January 26, 2021 2:41 PM > To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] Maybe a minimally printed harmonic drive? > > plus - you fold one inside out - the pitch doesn't match up very well. > > > On Tue, Jan 26, 2021 at 1:30 PM Gene Heskett <ghesk...@shentel.net> wrote: > > > On Tuesday 26 January 2021 13:04:11 Chris Albertson wrote: > > > > > The weak link on all 3D printed harmonic drives is the flex cup. The > > > plastic fails after some hours of use. The best design I've seen to > > > overcome this is to NOT print the flex cup. They used a wide double > > > side timing belt for the inner teeth. > > > > > > The thing that very few You tubers do when designing 3D printed > > > machines is to not simply copy the design of metal parts but start > > > the design from the ground up knowing they will be using plastic. > > > Plastic has very different strength and stiffness to volume ratios. > > > So if your part looks like the metal equivalent it is a good clue > > > you are doing "eyeball engineering" and your experience with metal > > > is influencing your design. > > > > > > If you need to print a reduction gear and need a really big ratio > > > the Cycloidic reduction system really does work better especially if > > > the rolling parts are sealed bearing units that are press-fit into > > > the plastic. > > > > > > That said, I've printed parts in plastic to directly replace metal > > > or even rubber and I just have to accept the very short lifetime and > > > low strength. Plastic is a good material to verify ideas quickly. > > > > > > In any case, use a timing belt for the flex wall and it might last > > > 30 years. > > > > > But that brings up the tooth profile problem. I've not seen a timing > > belt that resembles the triangular splines? > > > > > On Mon, Jan 25, 2021 at 8:47 PM Sam Sokolik <samco...@gmail.com> > wrote: > > > > I am sure the torque is limited - but I feel it might have > > > > possibility... > > > > > > > > https://www.youtube.com/watch?v=QlpkmEEhFqc > > > > > > > > _______________________________________________ > > > > 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) > > 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 > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > > _______________________________________________ > 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
