On Friday 12 April 2013 00:56:36 Jon Elson did opine: > Gene Heskett wrote: > > And I never considered the iron loses Jon, but you are dead on. > > Mariss Freimanis of Gecko describes some torture tests he did years ago > and reported this.
Humm, now that you mention that, I read something similar on the net a few years agom from somebody at Gecko. Could have been the same person I'd have to assume. > >> I make affordable servo amps for brushless motors, and > >> have one on my minimill. You do need to get rotor position > >> info from the motor, most small ones have Hall sensors that > >> you connect to the servo amp. I use 500 cycle/rev encoders > >> on mine, that is quite satisfactory. > >> > >> Jon > > > > That also makes great sense as long as its economical enough to do. > > The Gecko 201 series sells for $114, my brushless servo amp sells > for $150, for 20 A at 120 V. Which is 17 amps more than my lathe spindle has. I wonder if that could make me a REAL variable speed spindle. This one runs out of steam when the steel is above 5/8" in diameter. Supposedly a 250 watt motor, older 7zx12. I'd like to take it up to shaving 1.75" to 2" stock. Could that reverse w/o needing to toggle a 4pdt relay? > Not vastly more expensive than a > good stepper drive. Of course you need a PWM generator to run my > servo amp, but then you need a hardware step generator to get > full performance out of a microstepped stepper motor, too. True, if you can find the voltage for the motors. I hate paying 150-200 for a big linear when I can cobble something up out of the surplus catalogs for 1/3rd of that. Unforch, suitable transformers seem to be getting rarer as time goes by. The gears are turning on that spindle idea though. :) > Jon 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) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> "If you can, help others. If you can't, at least don't hurt others." -- the Dalai Lama A pen in the hand of this president is far more dangerous than a gun in the hands of 200 million law-abiding citizens. ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
