On 13 December 2012 03:39, Gene Heskett <[email protected]> wrote: > Another thing is (and I don't believe its related to the real problem here) > that if I slow the pwmgen's prr below about 1350 hz, the encoders velocity > output gets quite noisy, both in the signal and to my ears, its hunting > like crazy, but doesn't seem to effect the long term average, its just > slapping the nominally 5 degrees of play in the pulley keyways and timing > belt slop. Yet we've been told that a lower prr enhances the step level > smoothness by making it more base thread times wider, where adding a base > period to the length is a smaller percentage change.
This is only true as long as the timebase is significantly less than the time constant of the PWM to Voltage stage. I seem to recall that you swapped to a much smaller filter cap. I doubt that the spindle is oscillating at PWM frequency, but perhaps there is some aliasing effect in play. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
