hey andy thanks for the link they look cool
I already have a big harmonic drive the od is about 180 mm. and I have a matching servo motor to drive it. no crossed roller bearings but I could make it work easily. It is just that I think the thin wave gear in harmonic drives is not strong enough to hold up to heavy cutting forces. in comparison the cycloidal drives have 60 percent of the pins doing some of sort of work holding the thing rigid they look amazingly rigid and I think that is what new 5 axis machining centres use. anyway this is just a side line for now. I need to finish off the 3 axis mill stuff first and set up a qtpyvcp gui and work out the toolchanger. I will probably retrofit my cnc lathe also first while i am used to it then I will have a play with 4 and 5 axis I will be in touch with questions lol I need to learn HAL! regards Andrew regards Andrew On Wed, Apr 1, 2020 at 10:09 PM andy pugh <[email protected]> wrote: > On Wed, 1 Apr 2020 at 04:07, andrew beck <[email protected]> wrote: > > I have narrowed it down to either harmonic drives or Hypocycloidal gear > > boxes. > > > The FHA-25B harmonic drives are almost the perfect starting point as they > already contain a matched servo motor and very fancy cross-roller ring > bearing. > Specs here > > https://www.harmonicdrive.net/products/rotary-actuators/hollow-shaft-actuators/fha-c > But for easy retrofit use you want the -B version which has standard Hall > sensors and incremental encoder. > There is a relatively affordable on on eBay here: > https://www.ebay.co.uk/itm/153882616939 > I used one to make my 4th axis: > http://bodgesoc.blogspot.com/2017/05/harmonic.html > > Prior to that I had designed (possibly invented, I am not sure) this > easy-to-manufacture take on the cycloidal drive. > https://www.youtube.com/watch?v=VrvwlPxRhKU > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is designed > for the especial use of mechanical geniuses, daredevils and lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1912 > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
