On Thursday, December 16, 2021 1:10:30 PM EST John Dammeyer wrote: > A pencil line on both outer ring gears. The Blue 100 gear held tight. Turn > the Red Planetary cluster shaft and the Green 101 gear turns slowly. > > The assembly needs better mounting before backlash can be verified. This > design does look like it would be functional with a smaller 0.5 module gear > set with the ring gear holding at least 135T so that the 'rack' cutter can > be used. Largest set I have is 1.0module. > > I'm waiting for the Size 32 Chuck and collet set to connect onto my brand > name Harmonic Drive which is already connected as the 4th axis for my LCNC > system. It will be interesting to see if I can design a powered tool to > hold the cutter for milling the ring gears. And maybe upgrade my pattern > for the Harmonic Drive to allow horizontal mounting. Something Andy > doesn't need because he's got the horizontal mill. > > Meanwhile, figure out how to mount this huge monstrosity. > > John
Sweet John. Can you show us a pix from the blue side? And are the top and bottom pinions the same tooth count with the difference in the outer rings only? Thanks John. I am encouraged to see if I can make a smaller one when my printer is working again. > > > -----Original Message----- > > From: Todd Zuercher [mailto:to...@pgrahamdunn.com] > > Sent: December-16-21 8:19 AM > > To: Enhanced Machine Controller (EMC) > > Subject: Re: [Emc-users] Harmonic Drive > > > > DP is just the invers of module. > > > > 19tooth, 1.25module "should" be the right size sun gear for the 101/41 > > gear set, and 20tooth would be the one for the 100/40 set. But using them > > as ordinary planetary sets only gives a max gear ratio of about 37.9 to > > one running them compounded (6:1 * 6.316:1) Here is a nice site for > > playing with ordinary planetary gear sets. > > http://www.thecatalystis.com/gears/ > > > > However adding a sun gear to the input side of the original idea to turn > > the planet carrier instead of turning the carrier directly, might be a > > good idea (If you want huge gear reduction). That would add a 6:1 gear > > reduction multiplying the reduction significantly. (End result would be a > > whopping 404:1 gear reduction.) Holy crap that might just be getting a > > little out of hand. (How much reduction were we after in the beginning?) > > > > Here is a website that has the mathematical formulas for calculating a > > whole bunch of planetary gear arrangements. Including the two we are > > talking about here. The original idea is case#13 and this new one with > > the added sun gear input is case#15. > > https://www.engineersedge.com/gears/planetary_epicyclic_gear_13736.htm > > > > > > Todd Zuercher > > P. Graham Dunn Inc. > > 630 Henry Street > > Dalton, Ohio 44618 > > Phone:� (330)828-2105ext. 2031 > > > > -----Original Message----- > > From: John Dammeyer <jo...@autoartisans.com> > > Sent: Thursday, December 16, 2021 2:54 AM > > To: 'Enhanced Machine Controller (EMC)' <emc-users@lists.sourceforge.net> > > Subject: Re: [Emc-users] Harmonic Drive > > > > [EXTERNAL EMAIL] Be sure links are safe. > > > > The AlibreCAM Gear generator doesn't accept module. Instead it wants > > number of teeth and pitch diameter. > > > > So I whipped up a spreadsheet that converts say the module 1.25 that Todd > > used and chose 19 teeth for the sun gear. That appears to be the right > > size pitch diameter for the test setup. At least when I check it out > > with my calipers. But of course 19T don't fit. It has to be 20T and > > that then physically doesn't fit. > > > > So creating a true planetary set with all the gears fitting appears to be > > a bit more difficult. > > > > John > > > > > -----Original Message----- > > > From: Gregg Eshelman via Emc-users > > > [mailto:emc-users@lists.sourceforge.net] > > > Sent: December-15-21 8:22 PM > > > To: Enhanced Machine Controller (EMC) > > > Cc: Gregg Eshelman > > > Subject: Re: [Emc-users] Harmonic Drive > > > > > > Does FreeCAD's gear wizard support both Diametral Pitch and Module gears > > > now?> > > > > On Wednesday, December 15, 2021, 04:36:00 PM MST, John Dammeyer <jo...@autoartisans.com> wrote: > > > I still haven't been able to make a simple circle in FreeCAD. I keep > > > > > > looking for the Alibre way of doing it which for my brain has always > > > been close to perfect. Never could use AutoCAD and I find> > > Fusion360 confusing . > > > > > However the gear tool is quite nice in FreeCAD. > > > > > > I'm still having some problem visualizing exactly how the gears turn > > > to create 67:1. So I thought I'd blow a bunch of money on filament and > > > print them. In hindsight I should have expanded the pinion> > > holes to 22mm since that's a standard (cheap) bearing size. > > > > > Too late now. Just over 2 hours before the other 4 are done. I could > > > make some tubes that hold smaller diameter ones. Or just play with > > > the motion here first. See how it works and then decide if I want to > > > use my module 1.0mm cutters to make them out of metal. > > > > > > Or just print ones with inset relief to hold 8x22x7 standard bearings. > > > John > > > > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flist > > > s.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=04%7C01%7Cto > > > ddz%40pgrahamdunn.com%7Cf0e23e2e0c474d89921808d9c069626e%7C5758544c573 > > > f47cebee96c3e0806fb43%7C0%7C0%7C637752381126836342%7CUnknown%7CTWFpbGZ > > > sb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3 > > > D%7C3000&sdata=shhlXkCPj8ytCzxNUeNa5HZ3iPpEdTfuiLFMIzxvPhU%3D& > > > reserved=0 > > > > _______________________________________________ > > 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
