On Monday 20 July 2020 18:57:03 Jon Elson wrote: > On 07/20/2020 05:27 PM, Matthew Herd wrote: > > Working through Jon’s suggestions, the answers to his questions are > > as follows. Also, I’m running version 2.7.11 if that helps. No > > internet in my shop means it gets infrequent updates. > > > > Running the universal stepper diagnostics program with the command > > sudo .univstepdiags 378 bus indicates board 0 is firmware version 3. > > No board 1 is shown, boards 2 and 4-f are "No Board" and board 3 is > > "Unknown." > > > > Running the command sudo .univstepdiags 378 indexres 3 (from a forum > > post) gives me +517.00, +517.00, +517.00, and a jittery > > +0.000/+/-1.000 that seems to increase/decrease (depending on CW/CCW > > rotation) then go back to zero as fast as I turn the spindle. I can > > see numbers greater than 1, but they flash back to zero within a > > fraction of a second and keep jittering. > > Yes, that is normal. The position count is being reset to > zero each time the encoder passes the index position. > Turning it by hand, you might want to see it count up to > whatever your quadrature counts/rev is, before it resets. > If it keeps resetting to zero with just a little rotation, > then you are getting pulses on the Z channel that is > resetting the counter in between the index positions. That > would be a hardware issue with the encoder or encoder wiring. > > > The encoder scale on axis 03 is "setp ppmc.0.encoder.03.scale 2048" > > which is consistent with a 512 CPR encoder in quadrature. That’s > > what I’ve got installed. > > > > the connection to LinuxCNC looks like this: > > newsig spindle-index-en bit > > linkps motion.spindle-index-enable => spindle-index-en > > linksp spindle-index-en => ppmc.0.encoder.03.index-enable > > > > AND > > > > newsig spindle-pos float > > linkps ppmc.0.encoder.03.position => spindle-pos > > linksp spindle-pos => motion.spindle-revs > > > > At 3600 RPM (as reported from the encoder) the velocity is 60. At > > 3600 RPM CCW, the velocity is -60. I don’t readily have a means of > > verifying actual RPM, but the dial on the vari-speed head seems to > > read lower than actual RPMs, though I understand this is consistent > > with a worn varispeed drive. I also confirmed that one revolution > > appears to correspond to one increase/decrease of the > > ppmc.0.encoder.03.position as displayed by Hal Meter. I took care > > to rotate it one revolution as closely as I could manage and the > > results checked out. > > > > Regarding the index, I probed it with a meter and found the position > > at which it triggers. I can confirm that it should work as it > > showed 4.64V when at the index position. > > > > See below for my HAL files: > > > > univstep_motion.hal: https://paste.ubuntu.com/p/h66KJZx3hC/ > > <https://paste.ubuntu.com/p/h66KJZx3hC/> univstep_io.hal: > > https://paste.ubuntu.com/p/gMNkMwKDVw/ > > <https://paste.ubuntu.com/p/gMNkMwKDVw/> univstep_load.hal: > > https://paste.ubuntu.com/p/d36HgfwZ5Z/ > > <https://paste.ubuntu.com/p/d36HgfwZ5Z/> univstep_servo.hal: > > https://paste.ubuntu.com/p/wyb6JPX7ts/ > > <https://paste.ubuntu.com/p/wyb6JPX7ts/> xhc-hb04.hal: > > https://paste.ubuntu.com/p/w9mNn8hSdT/ > > <https://paste.ubuntu.com/p/w9mNn8hSdT/> pycp_panel.hal: > > https://paste.ubuntu.com/p/dVNwxHWJD2/ > > <https://paste.ubuntu.com/p/dVNwxHWJD2/> > > > > I realize most of these are not likely to be relevant, but I’ve > > included them anyway. The encoder is connected in the > > univstep_motion.hal file. > > > > Also, re-testing the behavior, I seem to get two different outcomes > > when I run G33.1. First error behavior is shown here: > > https://youtu.be/GMspKB5ZkoQ <https://youtu.be/GMspKB5ZkoQ> and the > > second error behavior is shown here: https://youtu.be/HJBOtFtXF5o > > <https://youtu.be/HJBOtFtXF5o>. In the first behavior (which > > appears to be random, but I didn’t restart axis repeatedly to test), > > the spindle is running before the G33.1 command. It feeds downward > > past the commanded 0.5" to 0.8125 or so, then stops Z motion while > > it decelerates. Then it reverses, spins up to speed, and retracts > > in what appears to be synchronized motion. The second error appears > > to do the same until it hangs somewhere after reversing. It also > > won’t respond to MDI commands. I had to go to manual mode and click > > the spindle stop button to get it to respond. > > I have no idea what is causing this. You might set up > halscope to trigger on the spindle reverse command and show > Z velocity and spindle encoder position. The G33.1 is > supposed to follow the encoder count until the command has > completed. Clearly, it follows it for a while, then stops > following it, and then in the first video it eventually > follows it in the reverse direction. > > I did not see anything wrong in your hal files. > > Jon
I think I'd drag out one of my 100+ MHZ scopes and look for noise of the type one might get from lack of a single point ground. And accidental ground loop from having the far end of a shielded cable grounded as thats generally a no-no. Even what looks like good shop wiring can get you in noise trouble. Best is to lift the grounds, one at a time, from that single bolt in the control box, and check it to see if its still grounded. If it still shows as grounded, find out where and isolate it, hook that ground back up to your central bolt and go to the next one until you have checked them all. This is called a "star ground" as it all starts at one bolt and does not connect to a ground anyplace but that central bolt. The static ground in the power service cable should only be connected to this bolt. That bolt, measured to a good dirt ground, may bounce 100 kilovolts in a nearby lightning strike, but so will the 5 or 24 volt stuff also connected to that bolt, and the voltage differential seen will still be that 5 or 24 volts as far as the electrical stuff is concerned, and none of it should be damaged by the strike that blew the 50kw cans fuses out on the pole in the alley. 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
