On Friday 23 October 2009, Dave wrote: >Yet another situation where more is less.. ;-) > >In a more perfect world I guess it might be best if everyone was running >1024 ppr encoders on their spindles and threading at 1000+ rpm and using >a hardware interface. > >Ironically if you want to thread on a really large lathe and need to run >at 60 RPM to do so, the position interpolated functionality would really >be required. > >Don't laugh at the 60 rpm, I am helping a guy on a big lathe CNC lathe >that can run much slower, I think 9 rpm is the lower limit on the spindle. > >Crazy slow. :-) > >Dave
And the max swing was 16 feet maybe? :) > >Andy Pugh wrote: >> 2009/10/23 Jon Elson <[email protected]>: >>>> Which is an interesting point. It seems that a hardware quadrature >>>> counter is likely to be counterproductive if you have a low-count >>>> encoder. >>> >>> I'm not sure it is COUNTER-productive, but if the spindle encoder >>> resolution times >>> the maximum spindle speed doesn't exceed the ability of the software >>> encoder counter, >>> than it doesn't GAIN anything. >> >> Perhaps I should have elaborated further. What I was saying is that if >> the hardware encoder and driver does not offer an interpolated >> position every servo cycle and the encoder pulse rate is low enough to >> have multiple servo threads per encoder count, then EMC will see a >> stationary spindle with the hardware encoder. This might cause the >> problems we are seeing. >> >> In that situation the software encoder, which does offer >> position-interpolated, is paradoxically superior. > >--------------------------------------------------------------------------- >--- Come build with us! The BlackBerry(R) Developer Conference in SF, CA is > the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference >_______________________________________________ >Emc-users mailing list >[email protected] >https://lists.sourceforge.net/lists/listinfo/emc-users > -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> I do desire we may be better strangers. -- William Shakespeare, "As You Like It" ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
