Just a warning, we had issues with a step/dir servo machine made with JMC integrated servos. They are way to slow controlled for a decent machine. Position loop is only 200Hz. This resulted in bad Path following => very ugly surfaces.
Yours Julian On 26 November 2020 17:51:44 CET, Gene Heskett <[email protected]> wrote: >On Thursday 26 November 2020 10:24:18 Thomas J Powderly wrote: > >> For Gene and others interested in RPi for LCNC >> >> https://www.youtube.com/watch?v=qL530kJUmII >> >I suppose ts nice for him, but the video of the machine moving at the >end >is very disappointing. His interfacing looks to be severely crippling >the maschines ability to move, I suspect because the latency is >relatively poorer, and cannot issue the steps to move the machine in a >timely manner, which going thru a parport synthesis seems to be >imposing. Software stepping would appear to be the problem. > >My early setup, now about 4 years old, started out on an 1 gig rpi3, >using a very short spi cable to a Mesa 7i90HD plus a triplet of >7i42TA's, is now, with the newer stepper servo's, moving my Sheldon >lathes carriage at over 150 IPM with the 3NM version on Z, and the >smaller 2NM is moving the crossfeed at 75 IPM, mainly it can't move far > >enough to get any faster. From a 2 gig rpi4. And doing it ghostly >quietly. And its loafing despite the fact its doing far more than >running a 3 axis mill thru a crippling sainsmart bob. The intelligence >available from the Mesa card offloads 90% of the job from the pi. That >bob has opto's in its inputs that can't pass a 5 kilohertz signal from >and encoder reliably. > >If one of my D525MW mobo's should die, I'd have no second thoughts >ordering up a duplicate of the hardware I'm running the sheldon with. >It >could do it on either 4 axis mill, far more stably that the wintel >boards have been. Uptime on that pi is 57 days right now. It just >doesn't crash. Raspian buster updated a library I had to reboot to >install and use. I put a small ups on it about a year ago and uptime >was >about 200 days when I rebooted it. > >Yes, its been an education getting it that way, but now it Just Works. > >> TomP >> >> >> >> _______________________________________________ >> Emc-developers mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-developers > > >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-developers mailing list >[email protected] >https://lists.sourceforge.net/lists/listinfo/emc-developers -- Mit freundlichen Grüßen aus Pinneberg Julian Wingert Subtilitas Consulting Holstenstr. 25 25421 Pinneberg Phone: 0170/4516094 FAX: 03212-1479681 Mail: [email protected] USt-IdNr.: DE272503212 _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
