A dual bearing block on both sides. Mount the 200 tooth ring to one block and
the 200+ tooth ring to the shaft on the other for the output. Mount the bar
with rollers to the other shaft and there's your drive. Put a little flange in
both rings to keep the flex ring centered. Lube it all very well with silicone
grease.
On Wednesday, January 27, 2021, 9:13:20 PM MST, Sam Sokolik
<samco...@gmail.com> wrote:
https://youtu.be/nhHDrK6sCRs
On Wed, Jan 27, 2021 at 3:56 PM Gene Heskett <ghesk...@shentel.net> wrote:
> On Wednesday 27 January 2021 16:04:45 Chris Albertson wrote:
>
> > This is a machine-tool related list. Many of us have 3D printers
> > too. So if you have both additive and subtractive tools available and
> > want to make a harmonic drive may be the best option is to make a
> > hybrid design with some parts of the drive made with different
> > techniques.
> >
> > Metal really is the best material for anything that needs to flex
> > because metal can be made so thin and is still strong when thin. 3D
> > printed plastic must be about the worst material for this.
> >
> > So I ask, Would it be possible to design an easy to make flex gear?
> > I think so. Most of the flex cup is made on a lathe then you mill
> > the teeth on the outside. I think it could be machined from a short
> > section of large-diameter steel tube. Then a bottom plate is press
> > fit.
> >
> > Maybe I could cut the teeth first, like making a gear, then place the
> > part in plastic holder and chuck the holder in a lathe and bore the
> > center out until the ring is very thin. The trick is to support the
> > ring with a 3D printed rigid backing fixture while boring it.
> >
> > The rest of the harmonic drive could be plastic.
> >
> > The big question for the group here is if the flex ring is something a
> > normal person could make one at a time. What kind of metal is best?
> > Is this kind of metal available in tiny quanity
> >
> > On Wed, Jan 27, 2021 at 12:36 PM Gregg Eshelman via Emc-users <
> >
> > emc-users@lists.sourceforge.net> wrote:
> > > Instead of a one piece flex cup, how about making a flex ring that
> > > connects to a rigid base with teeth or pins - something that
> > > interlocks but allows radial movement of the flex ring with respect
> > > to the base? No constant bending back and forth to break the print
> > > layers apart.
>
> I like this idea too. Cut or 3d print, the equ of a small pitch box joint
> on the bottom of the flex gear, matched to engage the "fingers" on the
> output disk, it could slid in and out radially on these "box": pins, and
> do it without the flex that normally breaks the cup off the disk at that
> joint. That would replace the spot that is the major breaking point,
> with a hinge like joint, which might prolong its life by many times what
> it is now.
>
> The splined part would then need to be restrained axially to keep it from
> wearing the ends of the cylinder it becomes, from rubbing on the
> housing. Perhaps a very mild dovetail? But that would lead to backlash
> and problems assembling it.
>
> Enough extra length on the cups pins to project a thou or so past the
> disk and drive a flat head 0-80 screw in the the end of the pin, pin
> sized so the angled underside of the head would prevent it from pulling
> apart. Wouldn't take a screw per pin, one in every 4th or 5th pins
> should do it. 3d print a bit of the 0-80's underside head angle on the
> disks fingers and screw head could actually sit below the disk face.
>
> 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
