videogamer wrote:I remember reading a while back that some soundmasters could do a signal where they would wind up, and then completely switch polarity on the motor to run backwards, stop, and produce a yelping signal.
That sounds like the answer. Only a (specify motor hp here) motor reversing would stop those rotors that quickly without damaging them.
On a side note, it's unusual that the Yelp signal on them ran that way instead of winding up all the way then reversing. I guess then it would be even closer to ACA's products, for which ACA sued them anyway.