On Tuesday 04 February 2020 06:33:05 andy pugh wrote: > On Tue, 4 Feb 2020 at 03:56, Jon Elson <[email protected]> wrote: > > I don't know if there's anybody out there with table travel > > that exceeds a 32-bit integer > > encoder count. > > Maybe not a table, but consider the spindle on a hobbing machine, > fitted with an ROD271 18,000 counts per turn encoder > running at 3000 rpm 24 hours a day. > S32 rolls over after 40 minutes. > So in rounded figures, and a 14,000+ count in low gear, i'd overflow in about 2 hours at 1500 rpms. I fairly certain I have exceeded that and have not noted any hiccups > Even a 4000 count encoder at 1000 rpm rolls over after 9 hours. > > 20,000 rpm spindles are common, but unlikely to use spindle-synch > motion. > > Rigid tapping and threading reset at the start of the cycle, so are > probably OK. > > S64 as the internal representation adds sufficient extra. Our first > example rolls over after 300,000 years. > So that becomes a never mind. Thats the sort of fixes I like. :) > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1912 > > > _______________________________________________ > 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
