Hey david that looks like a cycloidal gearbox anyway lol that is what I wanted to make.
If I can buy one sweet as no point re inventing the wheel regards Andrew On Wed, Apr 1, 2020 at 6:42 PM David Berndt <ber...@uberwin.com> wrote: > Alright, maybe i'm shooting myself in the foot here by inducing demand > and > I won't be able to get any cheap ebay units in future, but here goes... > > I bought a used spinea ts200 about a year ago and put a 750w servo on the > back of it, built an enclosure and use it primarily as a fixturing > positioner. It's awesome for my needs. 169:1 ratio. Position holding > under > light milling (think 5hp or less is my experience, I don't have a 40hp > beast to test with) > > I will say, from my limited 1 unit experience, the efficiency isn't great > if you want to get anywhere near top speed you'll have to swap the > grease, > or heat the unit, or just put a honking big servo on there. I have > trouble > getting over 10RPM without the servo running beyond it's continuous duty > zone. Maybe mine was filled with some sort of alternative grease in a > past > life, never opened it up to investigate. For positioning 10RPM is lots. > > I'm impressed with the milling stiffness. I've overhung a heavy walled 5" > square tube about 20" from the face of ths TS200 and use it as a 4 sided > fixture with no far end support and it still mills like a champ. I'm only > doing 2hp or less cuts in aluminum on that fixture, and I'm sure it'd be > better with a tailstock, but it's run for hundreds of hours making parts > without so far. The cross roller bearings in those units are quite > something. > > I haven't hooked up a brake of any sort, doesn't seem needed it for my > use > cases. > > One thing to maybe look out for if you care a lot about positioning is > the > these units have an angular transmission accuracy error/window that looks > something like +/- 17 arc seconds, differs for exact units, get specs > from > spinea for your model if you like. So if you care about resolutions > below > that, or lost motion then another solution, or a high resolution encoder > mounted on the output flange would be the way to go. I believe the strain > gauge units have a similar but different accuracy issue, perhaps software > compensation would even be possible? > > I'm also of the impression that the tilting stiffness and torsional > stiffness are significantly superior to the harmonic drives, but I could > be totally off there. > > -Dave > > > On Tue, 31 Mar 2020 23:03:11 -0400, andrew beck <andrewbeck0...@gmail.com> > > wrote: > > > 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. > > > > 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
