On Thursday 18 November 2021 17:57:19 Alan Condit wrote: > I built a new controller for my 9x20 lathe using a 5i25/7i76 combo. I > thought I had everything working but I still can’t get the spindle > working correctly. I have a 1.5hp PMDC treadmill motor that I am > controlling with a Cycletrol-150 DC controller. The am using the > analog out from the 7i76 to replace the potentiometer to control the > spindle speed. I have a 100 count encoder with index (homemade) on the > spindle. The spindle starts under LCNC control but I am not getting an > “at speed indication” at above 60rpm. > I might add that most of those treadmill controllers are far from linear controllers even with a large buildout resistor between the 7i76 card and their actual speed. The Pico Systems PWM-SERVO amp is the answer but be sure and tell Jon your are running a spindle motor with it which is a CCS load, it normally comes with an ICAS tuning for servo's which stop when they get there, spindles don't. The Pico will need a suitable analog DC power supply, whereas the Cycletrol probably runs from raw AC. I have used the treadmill controllers, a couple times, but never got good control so it was only till I built a better way.
Now I use large amounts of P-Gain and the only indication of excess load is when Jons driver throttles the motor at about 18 amps, making the iron in the motor chirp quietly. Thats right close to 2 hp from a 1hp rated motor but neither has even needed fresh brushes in years. > Sent from my iPad > > _______________________________________________ > 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, 1940) 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
