Thanks Gene! I can go down to 48 PPR on the encoder. If I do so, what is the trade off for reducing resolution on my mill project? Is that enough to successfully use rigid tapping and synchronized feed/speeds?
On Thu, May 7, 2020 at 5:45 PM Gene Heskett <ghesk...@shentel.net> wrote: > 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 > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
