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
