On Thursday 18 September 2014 20:29:43 [email protected] did opine And Gene did reply: > More fiddling and it appears the encoder is 2000 CPR. At any given > speed selection the spindle is turning a bit faster than specified, > with the difference becoming greater the higher the speed. I believe > this is due to it being a UK lathe and running at 60Hz instead of > 50Hz, at least the difference seems to match that ratio. As a result > the spindle-at-speed is staying false at all but the lowest speeds. > I'm not sure of the best way to deal with this, not using spindle at > speed, setting the tolerance rather high, something else? I seem to > recall there was a parameter somewhere for an analog output offset > that I could perhaps use, or how can I run the spindle closed loop and > let linuxCNC hold the exact spindle speed?
For closed loop, one generally net's the encoder's velocity output back to the PID.N.error, but IIRC you are not using a PID. So that is likely a dead end. 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> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that Matters. http://pubads.g.doubleclick.net/gampad/clk?id=160591471&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
