On Wednesday 11 April 2018 02:01:07 David Berndt wrote: > Wondering if anyone had any preference/experience/advise to share with > single phase capable larger servos. I'm looking at an application for > a 3 to 5hp motor with a vfd, but if I could just get a servo to fill > in that'd be nice. Gear reduction will be required, but something with > more torque, needing less reduction will make things easier.Say > ~500rpm as a goal maximum output. > > I see things like Fanuc red cap servos (ai series? pulsecoder encoder) > 2.5kw kicking around ebay. Driving something like that would seem to > be the challenge? > > Thoughts? Suggestions? Previous experience? > > Dave > The only comment I might make is that vfd's have a minimum usable speed they can drive a std "induction" motor, due to the current levels involved when trying to develop sufficient torque, causing ohmic heating in the motors windings, unless the motor has a hard armature, one permanently magnetized which in effect makes it a stepper. They are made, but my impression is that transferring the ownership is costly.
I've no clue where one could find a "slow-syn" of such a horsepower rating. But I'd suspect you would wind up using a honking big one. Rather than horsepower in such a case, I think you should be looking at stall torque instead. At my place, with a 1 horse 3 phase and a cheap vfd, I have a minimum hz shutdown at 10hz. And the motor is pretty warm in 15 minutes, but most lathe operations don't take that long. With the backgear engaged, thats less than 20 rpm at the chuck. But its not stopped, and its not a positioning servo. It may be the red cap is the answer, but I've zero experience with them. > ---------------------------------------------------------------------- >-------- 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 > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Cheers, Gene Heskett -- "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> ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
