John dammeyer I currently have a big harmonic drive but I think its not rigid enough. I have a 5 ton cnc mill with a 7.5 kw main motor and a full enclosure and i need a professional quality 4th axis hence looking for maximum accuracy and almost more importantly high rigidity and no backlash. I can always put a encoder on the end if we get crazy about it. Not sure what I actually need but it would be nice to machine something and then flip it 90 degrees and have a perfectly square. also I want to do simultaneous 4th axis machining so need a high rigidity without a brake though I will probably have a brake also. My dream is to offer 5 axis services here in new zealand as they are currently very expensive. its not like in america. a 5 axis machine is a big thing here. and If I can get one for e couple of thousand I will be stocked.
I have some massive angular contact bearing (100 mm id 250 on) and they will handle any machining forces if the gearbox is ok. On Wed, Apr 1, 2020 at 5:46 PM John Dammeyer <jo...@autoartisans.com> wrote: > > From: andrew beck [mailto:andrewbeck0...@gmail.com] > > > Hey guys. > > > > I have been thinking about my 4th axis I am going to make. > > > > I have my cnc mill working now though there is still a bunch of work to > get > > done. But I have been thinking about how I can make the best 4th axis > and > > after that 5th axis. > > > > I have narrowed it down to either harmonic drives or Hypocycloidal gear > > boxes. > > After Andy Pugh posted an Ebay link for a harmonic drive like his a couple > of years ago I jumped at it and bought it. I'm still way behind as I'm > just working on the crucible to hold enough aluminium to cast the holder. > Patterns are done and the STMBL runs it nicely sitting in the 3D printed > example of what I'll be machining. But no faceplate or chuck yet either. > > And does have his working with the STMBL drive. He's the best person to > report on harmonic drive for a 4th Axis. > > > > > I am thinking the hypocyloidal type looks the most rigid and best to make > > as it looks like the it would be very easy to make on a cnc mill and a > > harmonic drive relies on a thin strain wave gear that is not the > > strongest. I actually have a rather large one which I have been thinking > > about using but I would like to go with a the hypocycloidal design > instead. > > > > all you guys out there with awesome cncs sitting in your sheds have you > > ever built one of these? I don't want to reinvent the wheel if I don't > > have to. And I am on the track to making my cnc a 5th axis when I get to > > it. First I will make the 4th axis and pump a bit of work through it and > > make some money lol. But 5 axis looks pretty fun and cool and I think it > > is finally doable for the pro diy person. > > > > I have all the toys like a surface grinder and lathes etc and of course > the > > cnc mill. > > > > also don't mind spending money if needed as it is a business. > > > > here are some links to get the ideas flowing > > > > videos > > > > https://www.youtube.com/watch?v=Eds48L4cJjM > > > > fuson 360 scripts to generate the gear profile. > > > > > > https://github.com/mawildoer/cycloidal_generator/blob/master/README.md > > https://github.com/tapnair/Fusion360HypocycloidGear > > > > > > and just to show that it has been done before I say that the new Hass > > umc500 has cycloidal gearboxes in it so the design must be pretty good. > > > > > https://www.haascnc.com/machines/vertical-mills/universal-machine/models/umc-500.html > > > > > > regards > > > > Andrew > > > > _______________________________________________ > > 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
