On Tue, Oct 12, 2010 at 4:31 AM, Richard Arthur <[email protected]>wrote:
> My unqualified thoughts :-) > I've seen these spikes a lot whilst tuning the servos on my mill. I > think they are a characteristic of FF1 tuning. It is very tempting to > tweek FF1 and watch the f-error generally tumble, only to be left with > these spikes. Note from Screenshot4 that the spikes occur at the > transition from acceleration to constant velocity or vice versa. When > there is a reversal of the contribution made by FF1, it is almost > instantaneous and it simply isn't possible for the the servo to respond > fast enough. I found by improving the tuning at the amp and then EMC2's > P (I don't find I and D help much if at all), resulted in using much > less FF1 (the spike is always present, though much reduced). Having said > all that, I suspect these spikes have little or no effect on the > quality/accuracy of the machined part as the machine simply can't > respond fast enough (a point I've been unable to verify as sadly my > machine is down at the moment). > > i also find I and D almost no help. I want to find a way to tune the servo drives or to bypass the tuning component of the servo drives. I like the idea of bypassing the tuning component as that then gives me a consistent tuning interface between the machine and the man (me) no matter what flavor drive is on the machine. Hopefully this also will allow the tuning to exploit the best performance of all the components. The best scenario would be a simple (dumb) drive that only amplified the velocity signal. > Regards, > Richard > thanks Stuart -- dos centavos ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today. http://p.sf.net/sfu/beautyoftheweb _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
