On Wednesday 13 October 2021 21:09:54 Chris Albertson wrote: > You are right, but under all conditions, the resistor connecting the > wire to ground through a diode has lower impedance than the same wire > terminated at a transistor gate as was the case before. The proof is > that it works now. > > The other thing was thinking is that it should be simple to use > software to filter out a ghost pulse from an encoder. After all, we > know that it can only happen once per revolution. We could look at > the counter that racks A/B quadrature pulses and know it is is time > for an index. Software could do this even with no configuration by > spinning the shaft. In fact verifying that the index pulse always > happens at the expected time is a great way to error-check that no > counts were dropped or added. It would be a great self-dignostic.
I think I have the bones of such in at least 2 of my .hal files already. In order to establish the "SCALE" for this or that, I put in a method to measure 100 occurances of an index, and calculating that SCALE factor by recording the encoder count at the 3rd index, then recordiing the count at the 103rd index, and dividing that resultant difference by 100. I've done that three times now on the G0704, once for the two gears of the spindle, and then for the BS-1 as an A axis. That essentially same hal circuit could be used to gate the index, allowing an index to enter only if the difference says its due to occur. I used a different math in the A case because the figure I wanted is exactly a degree, not a 360 degree turn. This code works well in either case. I will use that same hal construct to calibrate the A on my 6040 when I take the A axis currently on the kitchen counter with my harmonic drive mounted on it, back to the 6040 and re-install it. The OEM version was 100x faster than it needed to be, and had virtually no holding power. I made the harmonic drive as a 30/1 but practicality says I should redo it as a 20/1, its a bit slow because the belt drive ratio is 21 to 83 in addition to the the 30/1 in the drive. More teeth on the output pulley might find me a tight enough belt to not need an idler as there virtually no place to put it that is now rigid enough. The belt problem is that they are not made in arbitrary sizes. So I should obtain the next longer belt, and expand the output pulley tooth count until its tight enough w/o an idler as the shaft separation is not adjustable. That project is waiting for me to find my round tuit and print a belt tensioning idler bracket that does work. Or adjust as described above. 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, 1940) 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
