Pity this guy claims he's lost the cad files. Seems a pretty good 3D printed harmonic drive. https://youtu.be/t4hW6lZYaQk
> -----Original Message----- > From: andrew beck [mailto:andrewbeck0...@gmail.com] > Sent: May-17-20 12:05 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Cheaper than normal FHA-25B > > I saw the fusion360 option. > > And I know solidworks can do that too. > > I would definitely want to mathematically calculate it. Seems a waste to > introduce error on the first step lol. Especially if I don't have to. > > Might be a good idea to 3d print the first one and then make a big proper > one from high tensile steel and needle roller bearings. > > Once I get to it I will post it here and on the forum. > > Have a cnc lathe to retrofit first haha. > > Now that this mill is almost done. > > > Regards > > Andrew > > On Sun, May 17, 2020, 6:23 PM Chris Albertson <albertson.ch...@gmail.com> > wrote: > > > There are two good tutorials on designing the gears. Both depend more on > > geometric construction than math. They first generate some points then > > fit a spine. I've read this is not-exact but the error can be as small as > > you like. Just make more points and the spline gets better. > > > > Going into the design you need to know what reduction you want and the size > > of the pins. For the pin size just use whatever drill rod you have. > > > > The second video uses Fusion360. The first one assumes any generic CAD > > system. These are not nearly as hard to design as involute gears > > > > > > > > https://youtu.be/guvatctnjww > > https://youtu.be/jQ6LQBFZXmU > > > > Robots are a good reason to own a CNC milling machine. I want one of > > these > > https://youtu.be/G6fMV1UPzkg?t=76 > > Seriously, they are just 12 motors, 12 gear reductions and a big LiPo > > battery. The motors come from quad-copter drones. > > > > > > On Sat, May 16, 2020 at 10:34 PM andrew beck <andrewbeck0...@gmail.com> > > wrote: > > > > > > Hey Chris. > > > > > > That's awesome. I was just looking at that video lol. > > > > > > Do you know how he is designing these. I know that the lobes are > > > calculated by a equation. > > > > > > It would be good to see the equations that go into this and any plug-ins > > he > > > uses etc. > > > > > > I'm quite keen to build one of these. Like you for robotics or just > > > anything. And of course my 4th axis on the VMC > > > > > > Regards > > > > > > Andrew > > > > > > On Sun, May 17, 2020, 4:39 PM Chris Albertson <albertson.ch...@gmail.com > > > > > > wrote: > > > > > > > Paul Gould is doing good work with these reduction drives. This video > > > > shows how a triple reduction system works and just how simple it is. > > > > > > > > Note that all the points of contact with the plastic lobes are ball > > bearing > > > > units. This unit is about as complex as they get and it is still > > easy to > > > > see how it works. But do notice there must be three dozen bearings > > total. > > > > At the end of the video where he spins the drive with the drill you can > > see > > > > the bearings all around the outside of the gear rotate. This is not > > > > required. Those can be made with pins or you can use a machined ring > > > > gear. > > > > > > > > https://youtu.be/ewoUsVMFWfU > > > > > > > > My use case for these is robotics but there is such a large overlap > > between > > > > robots and machine tools. I am building both a power steering system > > for > > > > a robot self-drive car and a z-axis for a Harbor Freight mini mill. I > > use > > > > the same motor and drive electronics for both of these. The only > > > > difference is the mill uses a 16mm ball screw and the car uses spur > > gears > > > > But the same NEMA23 motor. Paul is working on walking robots but > > there is > > > > no reason not to use one of his knee joints as an A-axis in a mill. In > > > > both cases you put a 2000 PPR encoder on it can use closed loop > > control. > > > > > > > > > > > > > > > > On Sat, May 16, 2020 at 7:53 PM andrew beck <andrewbeck0...@gmail.com> > > > > wrote: > > > > > > > > > > Chris > > > > > > > > > > So do they use some needle roller bearings that run on the lobes or > > > > > something? > > > > > > > > > > > > > _______________________________________________ > > > > 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 > > > > _______________________________________________ > 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
