On Thursday 01 October 2009, Steve Blackmore wrote: >On Thu, 1 Oct 2009 11:17:51 +0100, you wrote: >>2009/10/1 Steve Blackmore <st...@pilotltd.net>: >>> http://imagebin.ca/view/lUA3lv.html >> >>I am amazed that G33 works at all with that velocity noise. Mine is no >>more than 10% dither and is being blamed for my inability to thread. >> >>What sort of encoder is it? It looks to have a slot that isn't >> registering. > >Heidenhain - there's nothing wrong with the encoder, it's the third one >I've tried, all with the same effect. > >Here's a halscope of the encoder pulses > >http://imagebin.ca/view/1SkQrEB.html > And what I think I'm seeing is quantization noise in the time domain, the occasionally very narrow spike probably isn't there on your o-scope. But it (to me anyway) points to a problem in that the sampling is probably not being done in the base thread, but in the 1 millisecond thread. Can that not be moved to the base thread?
>From that halscope shot, I think I'd slow the spindle revs to 100 just to reduce the noise effects of the sampling jitter. >what you can determine from the pulse widths/spikes is inconclusive. > >Halscope shows pulse width variation, my Tektronix o'scope doesn't. > >I've another brand new 500ppr Stegmann encoder I could try, with Peter >Wallace's pulse reducer but I'm betting the results will be the same. >PITA to do, as the plug is different and I'll have to rewire the end. I >may try that tomorrow, I'll see how I feel, off to a Beer Festival >tonight so may be too fragile to wield a soldering iron tomorrow <G>. > >Steve Blackmore >-- > >--------------------------------------------------------------------------- >--- Come build with us! The BlackBerry® 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/devconf >_______________________________________________ >Emc-users mailing list >Emc-users@lists.sourceforge.net >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> "You've got to think about tomorrow!" "TOMORROW! I haven't even prepared for *_________yesterday* yet!" ------------------------------------------------------------------------------ Come build with us! The BlackBerry® 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/devconf _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
