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
