On Monday 13 July 2020 09:15:27 Ralph Stirling wrote: > Perhaps Peter could write a hostmot2 axis offset module that would run > in the fpga. No base thread needed.
I think thats a jolly fine idea. But I'd not have a clue where to start. > > -- Ralph > > On Jul 13, 2020 12:24 AM, Gene Heskett <ghesk...@shentel.net> wrote: > CAUTION: This email originated from outside the Walla Walla University > email system. > > On Sunday 12 July 2020 22:44:05 Leonardo Marsaglia wrote: > > > Currently - there is no way to adjust it. I do run the > > > acceleration and velocity as high as I can. (on the emco it is in > > > above 50in/s^2) I do have some math that calculates the following > > > error of the shape (actual shape vs axis position) and decide how > > > fast to run the spindle to get the tolerance I want. There should > > > be some sort of trajectory planning - but that might be above my > > > pay grade > > > > > > (mostly academic for me - just wanted to see how well it works...) > > > > Thanks for the feedback Sam. I'll have to dig in a little more to > > improve what I've done surely, but I guess only for the jobs I need > > to do from time to time the live tool is justified. I usually do 6 > > mm lift cams but sometimes I need to reach 9, 10 and even 11 mm of > > lift wich are almost dynamically impossible to turn with > > conventional tooling. > > I find trying to imagine the method intriguing, as I already have an > offset module in use on the Sheldon, doing compensation for bed wear > vs z position, something that can be done very cheaply in the 200 hz > jog thread, but thats obviously too slow for this. No reason I > couldn't map an offset vs spindle, usable at backgear speeds or maybe > even in 1st gear direct. Something I could feed into the offset thru a > sum2 from a lookup table based on a MOD of encoder by scale function > for the table index. Something like a 240 tap deep lincurve, but can > the pi4 handle that in real time. Doubtfull as I can see other timeing > problems Despite the newer power supply giving me 40+ ipm at the x > axis, I doubt the pi4 has enough processing power to pull that off. > The ultimate limit would be reached by adding a base-thread, which I > don't have now, because that sort of thing would need response at per > encoder edge. That speed limit then would be the 1 kilohertz > servo-thread write to the stepgen. > > One might experiment to find what those limits are with a siggen > module if it could be synched by a phase locked loop running at 6x > spindle index. Since its default is 1 hertz, it might make more sense > for testing to go to backgear and turn the spindle at 1/6th turn per > second, increaseing the gain of the triangle until a following error > occurs. And finding the minimum time for the phase-locked loop to > stabilize the spindle speed before advanceing the tool into cutting > position, I can imagine cutting a bolt head compatible with a 12 point > box end wrench, but not the pretty flats Sam got. That would require > running a sine signal thru an ABS function in real time adjusting the > gain for flatness of facets. Since thats a floating point function, > servo-thread at 1 kilohertz would be its speed limit. But is that > speed limit usable? > > IDK. :( > > Middle of the night thought experiments, darned things cost me sleep > but never get done... Ought to be a pill for that. > > > El dom., 12 jul. 2020 a las 15:52, Sam Sokolik > > (<samco...@gmail.com>) > > > > escribió: > > > Currently - there is no way to adjust it. I do run the > > > acceleration and velocity as high as I can. (on the emco it is in > > > above 50in/s^2) I do have some math that calculates the following > > > error of the shape (actual shape vs axis position) and decide how > > > fast to run the spindle to get the tolerance I want. There should > > > be some sort of trajectory planning - but that might be above my > > > pay grade > > > > > > (mostly academic for me - just wanted to see how well it works...) > > > > > > sam > > > > > > On Sun, Jul 12, 2020 at 1:32 PM Leonardo Marsaglia > > > <ldmarsag...@gmail.com> > > > > > > wrote: > > > > Excellent job Sam. > > > > > > > > One question to the list in general. How are you managing the > > > > atenuation and phase displacement you get when you increase > > > > spindle rpm using eoffsets? Other than increasing the speed and > > > > accel of the axis I mean. > > > > > > > > I could cut cams with some success but I really can't follow the > > > > shape > > > > > > and > > > > > > > the phase with the same success and that's why I'm building a > > > > live > > > > > > tooling > > > > > > > jig to cut at really low spindle RPM to avoid this effect as > > > > much as possible. My particular problem is worse because all the > > > > machining of the cams has to be aligned with a keyway in the > > > > camshafts. > > > > > > > > El dom., 12 jul. 2020 a las 5:12, John Dammeyer > > > > (<jo...@autoartisans.com ) > > > > > > > > escribió: > > > > > So question. > > > > > 1. would you post the G-Code that made that? > > > > > 2. I take it virtually 0 backlash on the cross slide? > > > > > 3. I was also impressed with how well the parting off went. > > > > > Mine tends > > > > > > > > to > > > > > > > > > dig in. > > > > > John > > > > > > > > > > > -----Original Message----- > > > > > > From: Sam Sokolik [mailto:samco...@gmail.com] > > > > > > Sent: July-11-20 7:39 PM > > > > > > To: Enhanced Machine Controller (EMC) > > > > > > Subject: [Emc-users] Because the hardware store was 4 miles > > > > > > away... > > > > > > > > > > > > Right? Am I right? > > > > > > > > > > > > https://nam05.safelinks.protection.outlook.com/?url=https%3A > > > > > >%2F%2Fyoutu.be%2Fwv7mMS5xKks&data=02%7C01%7Cralph.stirlin > > > > > >g%40wallawalla.edu%7C7901bb365f33404cbb4b08d826fdc544%7Cd958f > > > > > >048e43142779c8debfb75e7aa64%7C0%7C0%7C637302218677790598& > > > > > >sdata=FjZhLqoaiExh6SYV60FDOG6hpBLLQqquKs5UmDj10tA%3D&rese > > > > > >rved=0 > > > > > > > > > > > > _______________________________________________ > > > > > > Emc-users mailing list > > > > > > Emc-users@lists.sourceforge.net > > > > > > https://nam05.safelinks.protection.outlook.com/?url=https%3A > > > > > >%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&am > > > > > >p;data=02%7C01%7Cralph.stirling%40wallawalla.edu%7C7901bb365f > > > > > >33404cbb4b08d826fdc544%7Cd958f048e43142779c8debfb75e7aa64%7C0 > > > > > >%7C0%7C637302218677790598&sdata=E35uHmbI0c%2Bd5tDzpyDigst > > > > > >r6CoQ9SINjLuKrr7a3%2B8%3D&reserved=0 > > > > > > > > > > _______________________________________________ > > > > > Emc-users mailing list > > > > > Emc-users@lists.sourceforge.net > > > > > https://nam05.safelinks.protection.outlook.com/?url=https%3A%2 > > > > >F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&da > > > > >ta=02%7C01%7Cralph.stirling%40wallawalla.edu%7C7901bb365f33404c > > > > >bb4b08d826fdc544%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C6 > > > > >37302218677790598&sdata=E35uHmbI0c%2Bd5tDzpyDigstr6CoQ9SINj > > > > >LuKrr7a3%2B8%3D&reserved=0 > > > > > > > > _______________________________________________ > > > > Emc-users mailing list > > > > Emc-users@lists.sourceforge.net > > > > https://nam05.safelinks.protection.outlook.com/?url=https%3A%2F% > > > >2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=0 > > > >2%7C01%7Cralph.stirling%40wallawalla.edu%7C7901bb365f33404cbb4b08 > > > >d826fdc544%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637302218 > > > >677790598&sdata=E35uHmbI0c%2Bd5tDzpyDigstr6CoQ9SINjLuKrr7a3%2 > > > >B8%3D&reserved=0 > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://nam05.safelinks.protection.outlook.com/?url=https%3A%2F%2F > > >lists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=02%7C > > >01%7Cralph.stirling%40wallawalla.edu%7C7901bb365f33404cbb4b08d826fd > > >c544%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C63730221867779059 > > >8&sdata=E35uHmbI0c%2Bd5tDzpyDigstr6CoQ9SINjLuKrr7a3%2B8%3D& > > >reserved=0 > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://nam05.safelinks.protection.outlook.com/?url=https%3A%2F%2Fli > >sts.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=02%7C01%7 > >Cralph.stirling%40wallawalla.edu%7C7901bb365f33404cbb4b08d826fdc544%7 > >Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637302218677790598&sd > >ata=E35uHmbI0c%2Bd5tDzpyDigstr6CoQ9SINjLuKrr7a3%2B8%3D&reserved=0 > > 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 > <https://nam05.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgene >slinuxbox.net%3A6309%2Fgene&data=02%7C01%7Cralph.stirling%40wallawa >lla.edu%7C7901bb365f33404cbb4b08d826fdc544%7Cd958f048e43142779c8debfb75 >e7aa64%7C0%7C0%7C637302218677790598&sdata=5wbNnptZrvbzXDGR73xuHxGLd >Yb%2F2JNnAb9OgkT3lUg%3D&reserved=0> > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://nam05.safelinks.protection.outlook.com/?url=https%3A%2F%2Flist >s.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=02%7C01%7Cral >ph.stirling%40wallawalla.edu%7C7901bb365f33404cbb4b08d826fdc544%7Cd958f >048e43142779c8debfb75e7aa64%7C0%7C0%7C637302218677790598&sdata=E35u >HmbI0c%2Bd5tDzpyDigstr6CoQ9SINjLuKrr7a3%2B8%3D&reserved=0 > > _______________________________________________ > 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
