On Saturday 27 February 2021 08:08:49 Curtis Dutton wrote: > I've recently purchased a Fadal VMC 15 and I'll be retrofitting it and > replacing servos and electronics. The last machine I retrofitted was > an old miyano gang lathe and I'm driving the spindle and servos with > 8i20's. I just love them they are great. > > Is there any plan for a larger capacity 8i20? I wish I didnt have to > buy vfd's for large spindles and could use a super size 8i20. say up > to 10hp or so. > > Has this ever been discussed before? > I expect it has, but you get a lot more control bang per buck in the average VFD. I am continually impressed with what you can make a vfd do.
I have a 1.5 horse model running an elderly 1 hp 3 phase on my 11x56 Sheldon, and with an 8" 4 jaw chuck mounted, nearly 40 lbs, I can tap an m4 on the keyboard and the overtravel shown by some hal & pyvcp code, at 100 spindle revs is nominally .25 turns. That $130 clone vfd simply does what I tell it to do. And once I learned its limits, it hasn't complained in 3+ years. Or I can type s600m3, and less than a second later the pyvcp tach dial, driven by an encoder watching the bull gear, says 600 rpms. CSS works like magic. Type an m5 and its stopped dead in about 3 turns. Upping that to a 10hp would probably dim the neighborhood lights for that fraction of a second, but it would be done. No PID's in that config, the encoder is only used for threading and some timing on a spindle direction change sequence, and for some G33 stuffs. And its only an rpi3b, now a 2 meg rpi4b, doing all that. Whats not to like? You can't of course do that OOTB, but they are programmable, so teach it the Russian step dance. :) > -Curt > > _______________________________________________ > 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
