On Thursday 07 May 2020 17:39:32 Dan Henderson wrote: > Why certainly Gene (see attached). I actually have it working a little > better now. My spindle-at-speed LED will start going bonkers around > 1200 rpm. I'm guessing this is when the counter "throws up it's hands > and says - I quit!" lol. The spindle will operate all the way to > around 4700 rpm but anything above this and the MC-2100 shuts it down > -- must be some kind of voltage limiter kicking in then. > The one time I tried to use one of them was a failure, it seemed to have a mind of its own. I made a power supply and bought one of the pico systems pwm-servo's. Bulletproof but be sure and tell Jon you are going to drive a PMDC spindle motor with it so he'll add more toroids so it runs cooler when working continuously.
That said, your config is as well laid out as any I've looked at, and I don't see anything wrong at all. But I can also see how the parport and its missing of the encoders signals could be all of the higher speed problems. The 4700 limit might be the pwmgen going to 100% duty, losing the 0% recharge pulse. You can check that with halscope. I run more voltage than the mc2100 can muster, so I can spin a treadmill motor up to where I worry about the cast iron fan/pulley exploding but set limits somewhat below that, probably around 7 grand max. Even though its geared 3/1 before it gets near the spindle drive, its still too fast to cut steel. If you can set the encoder even lower you might get to a couple thousand revs before the tach gets funkity. 18:40 here, I'd better go see what my missus wants for dinner. > On Thu, May 7, 2020 at 2:29 PM Gene Heskett <ghesk...@shentel.net> wrote: > > On Thursday 07 May 2020 13:19:23 Dan Henderson wrote: > > > I believe this is open loop. Isn’t PID only used in closed loop > > > control? > > > > Its (the PID is) a waste of processor time if open loop. I don't use > > one of those in any spindle run by a vfd, the vfd is generally stiff > > enough control by itself. If I thread on that machine, it will have > > a spindle encoder, but its only job is to glue the axis motion being > > driven to cut the thread, to the spindle rotation, in the case of a > > g33.1, going both in and out of the hole. If you aren't useing a PID > > for the spindle, that leaves motion I think. > > > > I think its time we saw your .hal file. Can you insert it into a > > mail? > > > > > On Thu, May 7, 2020 at 11:03 AM Gene Heskett > > > <ghesk...@shentel.net> > > > > wrote: > > > > On Thursday 07 May 2020 11:27:57 Jon Elson wrote: > > > > > On 05/06/2020 09:20 PM, Dan Henderson wrote: > > > > > > I’ve confirmed the fluctuation occurs when spindle-at-speed > > > > > > is configured. When I remove this feature, the spindle rpm > > > > > > appears to stabilize. It’s almost like it gets caught in a > > > > > > loop trying to chase its tail. > > > > > > > > > > This is VERY common in servo systems, and is due to delay in > > > > > response of the object being controlled. > > > > > You need to slow down the response of the PID to ignore the > > > > > delay. This may be possible by adding > > > > > D to it. > > > > > > > > > > Jon > > > > > > > > But my msg was that a near module generated spindle.N.at-speed > > > > was never to be injected into any signal path leading back to a > > > > PID. That near's output s/b only to that input to motion, and > > > > possibly to an indicator led in the gui so the operator can be > > > > advised if its acting funkity. Flickering could be worn brushes > > > > in a brushed PMDC motor for instance. > > > > > > > > What you are describing as delays can often be fixed by the > > > > proper re-ordering of the addf's involved for the oscillating > > > > axis. That aspect of configuring LinuxCNC hasn't been mentioned > > > > recently or I wouldn't even have included that paragraph in my > > > > reply. > > > > > > > > And from Dan's description above, I think this is an entirely > > > > different critter from a timeing delay. > > > > > > > > Cheers Jon & stay well, 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 > > > > > > _______________________________________________ > > > 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) > > 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 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
