On Tuesday 08 December 2020 02:04:49 John Dammeyer wrote: > > I think I'd be measuring the ohmage and inductance of each winding > > in that motor. A partially shorted winding would be on my suspects > > list. > > > > They should match within a few %. A 10% diff would condemn it in my > > CET mind. > > > > Cheers, Gene Heskett > > -- > > Thanks for the suggestion. > I'll check that too although I'm leaning to epoxy PC board material > converted to conductive carbon. > > And doing the math if I change to an AC Servo rated at 3.5 NM at 2000 > RPM and update my pulleys to 4:1 from 3:1 I can go from 25 IPM to 125 > IPM compared to the stepper motor. > > A change to 4:1 is pretty easy. Just costs money for pulleys. > John > 125 IPM on a mills knee? That's earthquake territory when the knee weights 200+ lbs.
Take a look at maybe a 5/1 pulley set, and one of the new 3NM 3 phase nema 23 stepper servo's for a few bucks over $100. But you'll need to turn that 60 volt supply down as the driver is only rated to 50 volts. I've turned a pair of 48 volters down to 42.5, and am plumb amazed at what they are doing on my Sheldon lathe. Super quiet like casper the ghost. z is moving at over 120 ipm, compared to just barely 60 on a motor like the one on your mills knee. Had to use a shorter 2NM version for X as the 3NM was too long to put of the back side of the apron. Speed went up from 29 to the 60's, hard to measure as the cruising run is so short on X. They Just Work. And both have an error output that I've rigged to do an e-stop and unhome the machine if it trips but so far the only trips have been test trips from purposely running a tool into a stationary chuck jaw to test. At low speeds, spindle off, it isn't pushing hard enough to shatter or otherwise damage the chuck jaw or the chip in the tool, it just trips the machine off. On my lathe that trips off the motor power supplies, which resets the error, hit f2 to re-enable motion, pull the tool, rehome the machine, replace the tool, and restart the job. Whats not to like? 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
