On Thu, Dec 21, 2017 at 2:12 AM, Gene Heskett <[email protected]> wrote:
> On Thursday 21 December 2017 04:18:46 Chris Albertson wrote: > > > To make this really work for rotary tables you need a very fine pitch. > > I have seen these 3D printed in plastic but they slip and don't > > handle much torque because the outer ring deforms > > One idea I had was to press fit the plastic ring gear into a short > > section of steel pipe. > > > > Put you can buy these drives already made for about $250. That is > > really not abad price for arc-second level precision and near zero > > backlash. > > > Where? > I wrote that before I figured out how to see the video. On eBay you can fin harmonic drives. They do the something(roughly 1:100 reduction) but actually better accuracy. Here are a few: ebay.com/sch/i.html?_nkw=harmonic+drive... <https://www.ebay.com/sch/i.html?_nkw=harmonic+drive&_in_kw=1&_ex_kw=&_sacat=0&_mPrRngCbx=1&_udlo=50&_udhi=275&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=90278&_sargn=-1%26saslc%3D1&_salic=1&_sop=12&_dmd=1&_ipg=50> > > On Wed, Dec 20, 2017 at 10:15 PM, Lawrence Glaister <[email protected]> > wrote: > > > very cool Gene.... had some troubles playing the video, but I seem > > > to have the gist of it. It does seem like a very interesting design > > > for rotary tables.... just have to figure out how to re-purpose some > > > rear end ring gears and pinions.... hmmm... was thinking of > > > regearing the jeep anyway!. Lawrence Glaister VE7IT > > Now theres a recipe for some bigger machinery, > Maybe a better source of parts would be a Toyota Prius viable ratio transmission. It is already set up with planet gears that match the ring. The parts come off without even needing tools. See the ring and planet gear on the left and center of this video. Junk yard price is about $300. Also notice the two electric motors. They could like be repurposed. > > -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
