> > That simplify's things greatly then, any gpio can be hooked to a counter > to measure frequency per period, with something in hal setting the > period. Piece of cake. Several flavors available. > > Speed of counters in the pi clone might be a problem. I've found the > encoders in a 5i25 can track a 1k ppr encoder on the spindle motors back > shaft. but the 7i90HD would need that counter in its firmware to keep > up. My problem in the original rp3b wasn't the encoder speed, but the > lathes ability to track the 100 ppr encoder dials, so I added a third > execution loop, running at 200 HZ just for my manual control stuff. I > can still spin a knob faster than it can move but it catches up in a > fraction of a second. The rpi4 in there now may do the same but its not > detectable as a general rule. And has no effect on gcode speed. That pi > and monitor are never turned off, it controls all power to the lathe > with the F2 button driving SSR's.. pi and monitor are 22 watts. pi > uptimes are from maintenance session to maintenance session as I have a > tiny ups on it, and a autostart kohler 20kw in the back yard. Originally > installed for the wife's COPD, but she passed 4 years ago tomorrow.
Well, I plan to run every counter on hardware since it's hard for me to get a good low latency machine for LCNC use. So I don't bother anymore and just leave it all in the hands of hardware counting. Sorry about your wife Gene! Not to bad for a 90 yo diabetic, fixing to get some stents put in my > legs as soon as they get a cat scan to find where the others are. Take > care yourself Leonardo. Well, with your age you're doing way better than most people including myself, and I'm only 35! Happy to hear from you Gene! :) El vie, 6 dic 2024 a las 11:40, gene heskett (<ghesk...@shentel.net>) escribió: > On 12/6/24 06:56, Leonardo Marsaglia wrote: > > Hi Gene! How are you? > > > > Leonardo, If looking for a bunch of encoders, Peter may be able to build > >> a 7i90HD file to order. It has 72 i/o pins. So there's buckets of i/o. > >> With 4 encoders, I'm using 3 of them on the Sheldon, One for the > >> spindle, and two replace the cranks on the apron that allow me to drive > >> it by hand. The dis is the cost as it needs 3 7i42TA's to guard its > >> gpio pins from over 3.5 volts of logic. The config I'm using has 4 > >> encoders stock. It can be used with a parport breakout, or with a 3 wire > >> spi interface at quite blazing data speeds (42 megabaud writes, 25 > >> Megabaud reads) with an rpi4b clone doing the work. > > > That is in 32 bit packets going both ways. > > > > Do you mean 7i42TA? > > Yes, mental typu there. fixed in echo above. > > that's probably another option. I only need to read > > frequency so I don't need quadrature or direction, so as Peter says I'll > > have more pins available. > > That simplify's things greatly then, any gpio can be hooked to a counter > to measure frequency per period, with something in hal setting the > period. Piece of cake. Several flavors available. > > Speed of counters in the pi clone might be a problem. I've found the > encoders in a 5i25 can track a 1k ppr encoder on the spindle motors back > shaft. but the 7i90HD would need that counter in its firmware to keep > up. My problem in the original rp3b wasn't the encoder speed, but the > lathes ability to track the 100 ppr encoder dials, so I added a third > execution loop, running at 200 HZ just for my manual control stuff. I > can still spin a knob faster than it can move but it catches up in a > fraction of a second. The rpi4 in there now may do the same but its not > detectable as a general rule. And has no effect on gcode speed. That pi > and monitor are never turned off, it controls all power to the lathe > with the F2 button driving SSR's.. pi and monitor are 22 watts. pi > uptimes are from maintenance session to maintenance session as I have a > tiny ups on it, and a autostart kohler 20kw in the back yard. Originally > installed for the wife's COPD, but she passed 4 years ago tomorrow. > > > > Hope you're doing great! > > Not to bad for a 90 yo diabetic, fixing to get some stents put in my > legs as soon as they get a cat scan to find where the others are. Take > care yourself Leonardo. > > > El mié, 4 dic 2024 a las 11:34, gene heskett (<ghesk...@shentel.net>) > > escribió: > > > >> On 12/4/24 06:21, Leonardo Marsaglia wrote: > >>> Hi Andy, > >>> > >>> 7i89? > >>>> > >>>> Not as many encoders, because there are not as many pins... > >>> > >> Leonardo, If looking for a bunch of encoders, Peter may be able to build > >> a 7i90HD file to order. It has 72 i/o pins. So there's buckets of i/o. > >> With 4 encoders, I'm using 3 of them on the Sheldon, One for the > >> spindle, and two replace the cranks on the apron that allow me to drive > >> it by hand. The dis is the cost as it needs 3 7i44TA's to guard its > >> gpio pins from over 3.5 volts of logic. The config I'm using has 4 > >> encoders stock. It can be used with a parport breakout, or with a 3 wire > >> spi interface at quite blazing data speeds (42 megabaud writes, 25 > >> Megabaud reads) with an rpi4b clone doing the work. > >> > >> Had I built my 1940's Sheldon 11x54 first, I would never have used > >> anything else in my other 3 cnc'd machines. The other 3 were done first, > >> are run by big old Dells, with a 5i25 in the Dell and a 7i76D plus a > >> parport breakout, usually with the opto-isolators bypassed for speed. > >> That 5i25 encoder is watching a 1000 ppr encoder on the rear of the 1hp > >> motor on my GO704, rated for 1800 rpm but has not dropped a bit ever > >> once the opto's in the parport were bypassed. That 90 volt motor with my > >> 124 volt psu can do 21,000 rpms wide open. I'm amazed I haven't blown > >> the nylon gears in the heads gear-shift. I've been abusing it that way > >> since 2009. And still on the same factory brushes. I have i/o enough > >> left on that Sheldon build to run an Emco tool changer if I ever find > >> one I can afford. > >> > >>> Yeah, that seems like another option. > >>> > >>> El mar, 3 dic 2024 a las 22:52, andy pugh (<bodge...@gmail.com>) > >> escribió: > >>> > >>>> On Tue, 3 Dec 2024 at 15:32, Leonardo Marsaglia < > ldmarsag...@gmail.com> > >>>> wrote: > >>>> > >>>>> The main concern to decide my configuration is: Is there a 7i53 like > >>>> board > >>>>> that uses the SERIAL I/O interface instead of the 50 pin connector? > >>>> > >>>> 7i89? > >>>> > >>>> Not as many encoders, because there are not as many pins...[...] > >> 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 > >> 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 > > > 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 > 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
