This is all Gene’s fault. :-) His evangelism of steppers-servos has penetrated my thick skull. Side note: tinyG has signal pickoff before the final stage so it is possible to drive stepper servos off a tinyG.I’ve not gotten there yet but headed that way. Of course “the difference between theory and practice….” Be patient nothing I do these days is fast or efficient. Stay tuned!
D > On Feb 22, 2025, at 5:41 PM, gene heskett <ghesk...@shentel.net> wrote: > > On 2/22/25 18:29, Dave Engvall wrote: >> There is a method to my madness, to wit I really want to know how good, or >> bad the tinyG is. Older version of the emc interp but a much faster cycle >> time. Glass scales are problematic for velocity control but rather good for >> position. Servos on that machine with good encoders on the ball screw were >> much better at velocity control, roll that in with a glass scale for >> position and you have the best of both worlds. > I've had very good results on the one machine I have converted to closed loop > stepper/servo's. Totally doing away with the PID's. Feedback is from the TP > that drives that axis, the stepper/servo's have their own PID's. My sheldon > rapids are 2x faster, and quite a bit more accurate. The TP outputs good > code. These motors stay w/in a count of error And it makes beautiful metal. > Well within the thousandths I wrote the code to do. No ticklish PID tuning > ever, no PID's to function as rubber bands, so what the TP spits out is > exactly what the motor does. >>> On Feb 20, 2025, at 1:41 AM, Todd Zuercher <tzuercher1...@gmail.com> wrote: >>> >>> If they are equidistant wouldn't simply use them the same as an ordinary >>> encoder index signed? >>> >>> On Thu, Feb 20, 2025, 4:09 AM Andy Pugh <bodge...@gmail.com> wrote: >>> >>>> >>>>> On 19 Feb 2025, at 17:15, Dave Engvall <dengv...@charter.net> wrote: >>>>> >>>>> I think both have R marks at 50 mm intervals. >>>>> Seems logical? >>>> There are systems where the index marks are at varying distances from each >>>> other such that you know exactly where you are after seeing two marks. >>>> There was discussion of this on the forum, which resulted in the homing >>>> process being modularised, (HOMEMOD) >>>> I don’t recall if we saw a suitable HOMEMOD module for this style of scale >>>> in that thread. >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> 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 >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net <mailto:Emc-users@lists.sourceforge.net> >> https://lists.sourceforge.net/lists/listinfo/emc-users > > Cheers, Gene Heskett, CET. > -- > "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 > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net <mailto: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
