On Monday 28 May 2018 15:09:00 Jon Elson wrote: > On 05/27/2018 10:54 PM, Gene Heskett wrote: > > To Jon; I had to reset the pwm-servo several times, it was > > tripping off at the m5, which is completely off while the > > motor was cranking the spindle at 1500. So thinking about > > the motors emf, I put an s100, g4p.5 in front of the m5. > > Hasn't tripped again. > > Yes, you certainly don't want to do a harsh reversal. Even > with a VFD on my Bridgeport, I have a lowpass filter to make > the spindle start/stop and reversal more gradual. I put the > filter in between > motion.spindle-speed-out and the DAC that drives the VFD. > In this particular case, the VFD takes digital direction > commands and a unipolar speed command, so I use the abs > component to convert +/- values to all +. > > net spindle-speed motion.spindle-speed-out => mult2.1.in0 > setp mult2.1.in1 0.002457 > net spindle-DAC-cmd mult2.1.out => lowpass.0.in > net spindle-DAC-filt lowpass.0.out => abs.0.in > setp lowpass.0.gain 0.005 > net spindle-DAC-abs abs.0.out => ppmc.0.DAC.03.value > > Doing it with the filter means you never have to think about > doing this in every G code program. > The first setp has a cal factor for one belt ratio setting > to spindle speed. The second setp sets the time of the > lowpass smoothing. You can also use limit3 to do this. > > Jon
I'm using a limit3 in front of the PID command in. Just enough lag to make a 2800+ to 2800- in about 400 milliseconds in high gear. The amp (or the motors iron) lets out a faint chirp from the overcurrent kicking in at about 16 amps. Go for 1400+ to 1400- in low gear is a bit slower, more overshoot at the bottom of a rigid tap, and still gives a very short chirp thats easy to miss. And I don't recall ever getting an error trip doing that. Both are well above the motor max rpms when it was running on the oem 90 volt controller. Its in a keep box someplace in the garage. :) I'm guessing that with your control and a supply big enough to manhandle that motor, that I am getting close to 2 hp out of it at peaks. > > ---------------------------------------------------------------------- >-------- 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
