On Friday 29 November 2013 20:34:44 andy pugh did opine: > On 30 November 2013 01:01, Gene Heskett <ghesk...@wdtv.com> wrote: > > But what then becomes the position feedback? > > Ideally something high-count on the table itself. Such as a Renishaw > Resolute. > > For the smaller budget, an 18 pole motor with 6 hall phases and a 90:1 > harmonic drive has 9720 phases per rev, and might be enough to work > with. > (half a minute resolution, so you would need to not be too fussy)
Since I use it for angular positioning while drilling holes at odd angles, or for tool sharpening with a diamond disk in the spindle, half a minute would have me dancing the streets. :) But I haven't checked around for a harmonic drive of a suitable size that I could also afford. I suspect those are in the same box in the safe as hens teeth, or inlaid silver contacts for a 1200/amp a phase Zenith transfer switch. In 1972, $75 USD/copy, 6 stationary, 6 moving. I was 100 USD short of having to call in a quorum the Nebraska Unicameral legislature to authorize the purchase order. UHF television transmitters using klystron amplifiers are Hungry, with a capital H. A 150 kw, Cummins 335 cranked standby generator could only run it at 1/2 power & manage to stay above 58 hz. Looking on ebay, I do see some affordable ones that might bear looking into but those also look as if suitable housings and output tables would have to be built from the corner scrap pile. Not exactly an overnight job... Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> The truth of a thing is the feel of it, not the think of it. -- Stanley Kubrick A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349351&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
