I agree. Rather a nothing video. Took about 30 seconds to view it skipping past the "these are screws in my hand" parts. And clicking on the x in the advertising that kept popping up.
I too would like to build a robot arm to replace the Radio Shack Armatron I bought while on holidays in the late 80's. https://en.wikipedia.org/wiki/Armatron My wife sat outside the trailer sun tanning. I played with it inside where it was cool. My kids played with it when they were younger. Now it's back in the box ready for grandchildren. But a larger scale one with harmonic drive joints would be fun. John > -----Original Message----- > From: Chris Albertson [mailto:albertson.ch...@gmail.com] > Sent: February-22-21 11:15 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Harmonic drive, rubber flex ring > > The Youtuber is just making stuff to show on Youtube. If he had a specific > use-case, then he would have to choose the system. Cycloidic drive can be > back driven and have a lower reduction. If you need that, you need that. > Harmonics can't be back driven and can have 100:1 reduction. The two are > not really interchangeable. > > My interest in this is robotics. THis is the entire reason for using > LinuxCNC andmachine tools is to make parts for robotic related experiments. > I've not given up on belt reduction. A three-stage reduction with 4:1 > pulleys can fo a 4x4x4 = 64:1 reduction with very little friction. It > competes will with harmonic and cycloidic reduction. If designing > something you have to explore all these options as there is never a "best", > only a "best in this case". > > On Mon, Feb 22, 2021 at 10:43 AM Ralph Stirling < > ralph.stirl...@wallawalla.edu> wrote: > > > Interesting video, and also interesting that the guy has > > abandoned the harmonic drive in favor of cycloidal > > drive. > > > > -- Ralph > > ________________________________________ > > From: Chris Albertson [albertson.ch...@gmail.com] > > Sent: Monday, February 22, 2021 10:17 AM > > To: Enhanced Machine Controller (EMC) > > Subject: [Emc-users] Harmonic drive, rubber flex ring > > > > CAUTION: This email originated from outside the Walla Walla University > > email system. > > > > > > To add one more idea to the long-running conversation of how to build a > > harmonic reduction drive. Here is a working prototype that looks like the > > flex-cup solution is solved. This could work for many years. But the > > video shows only the idea and a prototype. I would not make this one but > > rather use the idea. What is needed is better bearing to support the load. > > > > What I would do is make a sturdy metal shaft that connects the output disk, > > rotor, input disk and motor, maybe using tapered roller bearings and then > > the motor turns the shaft perhaps through a flexible urethane coupler. > > Ideally there would be an optical encoder disk buried inside someplace too. > > > > The prototype in the video has nothing but gravity or the user's thumb to > > hold it together but it does solve the harder problem of the flex-cup that > > can last for many years. > > > > > > > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyoutu.be%2F9DwqN1pEkVg&data=04%7C01%7Cralph. > stirling%40wallawalla.edu%7C9d6a2020ac674f4b088e08d8d75e2eba%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C6374 > 96146796527482%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D% > 7C1000&sdata=YBD%2FKZovPfTef91aE6pGGouAoBcUP%2BKB2ZVe4cJCsVY%3D&reserved=0 > > -- > > > > Chris Albertson > > Redondo Beach, California > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > > > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc- > users&data=04%7C01%7Cralph.stirling%40wallawalla.edu%7C9d6a2020ac674f4b088e08d8d75e2eba%7Cd958f048e43142779c > 8debfb75e7aa64%7C0%7C0%7C637496146796527482%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiL > CJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=OhcfGIXX%2F338hnNQvan%2Fmo3LNWTyjTOboqRaAw591JA%3D&r > eserved=0 > > > > > > _______________________________________________ > > 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 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
