Do you have a dual trace 'scope? Spin the spindle and look at the input and output of the opto-isolator. See if there really is a lag. If you have a new scope would you have it capture the screen and post it. I'm really skeptical that those isolators are THAT bad.
Here is the datasheet for the opto. https://www.mouser.com/datasheet/2/143/EL817-G-26528.pdf They claim an 18 uS rise and fall time. A 1KHz square wave will have a 1000 uS period and a 500 uS pulse width at 2 KHz the pulse width is still more than 10X the raise time of the opto. But maybe the opto is a fake counterfeit part with very poor performance. Check it out on the scope and if you can post the results. I have a few of those way-cheap BOBs too in a drawer. I think I will test them and maybe post a screen shot. My bet is the the problem is the parallel port. I just can't see how to get encoder data reliably through a parallel printer port. On Tue, May 5, 2020 at 6:21 PM Dan Henderson <[email protected]> wrote: > I have LinuxCNC fully operational. In halscope I’m able to view the signals > for both the spindle index, phase a, and I now have phase b hooked up. I’m > conducting my testing with the LinuxCNC MDI. The number on the opto chips > is EL817C807. > The BOB PN is DB25-1205. > > > > On Tue, May 5, 2020 at 8:08 PM Gene Heskett <[email protected]> wrote: > > > On Tuesday 05 May 2020 20:17:45 Dan Henderson wrote: > > > > > Slowing things down had marginal effect. Okay sounds like I need to by > > > pass the optocouplers. Would you recommend I bypass all the encoder > > > inputs as well as the PWM output to the MC2100 controller? > > > > Only if it has opto's for isolation, they can effect to duration of the > > pwm playing hob with the speed linearity. If the motor is "hunting", > > something else is going on. The m2100 ISTR is the controller that came > > in the treadmill and its a very serious case of built by lowest bidder, > > I was not able to use it in anything I've tried. Control was extremely > > non-linear until I put a 47k resistor between linuxcnc and its summing > > point, That helped but it was still flaky. Not to mention that all of > > its control circuitry is on the hot side of the power line and quite > > dangerous. > > > > I am not a machinist, but a long retired broadcast engineer and a CET so > > much of the high power stuff comes out of my junk box. The psu for > > instance, makes about 120 volts DC at a surge current of 20 amps, 10 > > forever, way more that the 1hp motor I'd put on the back of a 7x12 lathe > > is rated for. Capable of getting 2hp out of that 90 volt motor. But it > > kept breaking drive parts once I had obtained one of the pico systems > > pwm-servo drivers. So I've gone into the hal file and slowed the motors > > acceleration to something that doesn't break stuff any more. But that > > might explain why my troubleshooting is geared to the electronics, and > > possibly is different than what a real machinist might do to solve an > > identical problem. > > > > Other than that it doesn't sound as if the opto's speed is your problem. > > > > So 2 other questions: > > > > What to you have in the way of meters and oscilloscopes for > > troubleshooting? > > > > Do you actually have LinuxCNC running well enough to try to control your > > motor? > > > > 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 > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
