On Wednesday 06 May 2020 09:14:20 Dan Henderson wrote: > Here are a couple screen shots of the encoder inputs using Halscope. > The first is captured at 300 rpm spindle speed. The second is at 2500 > rpm. The signals are inconsistent at the higher speed. Not sure if > this is normal or an issue?
That _is_ the issue. Ir you have a real scope, take a look at the cable from the encoder.. If you still see that, the encoder is the problem. Conversely if that looks good, the port is mussing pulses > On Wed, May 6, 2020 at 7:01 AM Dan Henderson <luvtof...@gmail.com> wrote: > > A lot of great input here. I’m not sure I fully understand all of > > the talking points around kHz and PPR and RPM vs optocoupler speed > > and parallel port timing. > > > > I also have 3 stepper motors in xyz that are being controlled via > > the same BOB parallel port combo. They appear to be working okay > > with the exception of maxing out at 1” ips jog speed before they > > lose steps. That seems slow to me. They are nema 23 425 oz-in with > > DMQ542 drivers rated up to 80v. I’m only supplying them 36v. More voltage will help. Those 425 motors are fairly high inductance windings and they need more volts to get sufficient current flow at the higher speeds. You must have newer 542's than I, mine are only rated for 50 volts. I'm feeding mine around 42 volts, peaking at about 90 ipm. Or 1.5 ips. When I bought a kit to cnc this g0704, it came with a 1600 oz z motor because the head is so heavy, but its top speed going up was about 27 ipm. I replaced the 1600 with a 940, and its DM860 driver with an AC powered unit that made more coil voltage, that 940 can now lift the head at 90 ipm. [...] 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
