ORIGINAL: 747drvr
I've had 4721's do the same thing . They get into a funky kind of harmonic .
Marc
Keep in mind that when the 2721s/4721s are shake-rattle-and-rolling that each servo is drawing over 1 amp of current which ain't good. I would urge anyone that is observing this phenoma to replace the offending servos ASAP.
Gordon