On Sun, 7 Jun 2026 at 13:03, Luca Toniolo <[email protected]> wrote: > We do not have to hypothesize, because we already hit this. hostmot2 > computes a 64-bit internal encoder accumulator specifically to stop > high-count encoders wrapping:
We have one(?) known case of a high-count encoder on a high speed spindle wrapping at 32 bits. I think it took a long time to happen. In that case even an extra 5 bits would probably have solved the problem, making the wrap take a month rather than a day. There may be cases where 53 bits isn't enough, but they don't seem realistic. For example if we take the case of a 32-bit encoder on a high-speed spindle running at 100,000 rpm (and it makes no sense _at_all_ to have a 32-bit encoder on a spindle) then it would start to become inexact in a float after 20 minutes of running. (whereas with the full 64 bits this would wrap in a month) Note that 32 bit encoders are probably the highest current resolution, and are intended for angular measurement, not for counting multiple revolutions. And they probably can't handle 100k rpm. -- 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
