On Sunday 13 May 2018 19:45:42 andy pugh wrote: > On 13 May 2018 at 23:58, Gene Heskett <[email protected]> wrote: > >> You need to use the "invert" function to get a reciprocal. > > > > This is at the output of the mult2? > > On one of the inputs, normally.
Ok, makes perfect sense. > > > I think this brings up another accuracy reducing problem, the > > reciprocal of the effective low gear encoder_scale is .000070947. > > Isn't that beyond the 8 decimal places linuxcnc uses? > > HAL is floating-point, so there are no practical limits on decimal > places. (That's a G-code limitation) Well, even if it loses the last 2 on the right, it s/b close enough to work. G-code is involved, but its values won't range any wider than 80 tpi, up to possibly 2.00000 max. So that won't, or shouldn't be a problem. G-code is also involved as the src for invert, so we'll compare its output with a TI calc that shows 10 digits. If a diff, its way out into micron territory. More tomorrow after the morning coffee kicks in. :) If we aren't blown away that is. Frigging weather is beating us like a white mouthed mule. Very high winds and heavy rains 40 miles north of here, moving this way. 6 hours later, half a cuppa, I've made some progress, but need the main psu turned on to check any further, no power to the gear tally switches. And at 5am, its all quiet, they've called off the bad weather warnings for a few hours, so going back to bed. Thanks Andy. -- 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) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
