There seems to be two mechanical strategies at work in the SawStop, of
translation, and of rotation, ie, retracting the blade, and stopping the
rotation.

It seems to me one would be sufficient, with retraction having the advantage
of being non-destructive. Not sure if the blade is direct drive or belt
drive, but if it was belt drive, the retraction could all the more rapid,
since you would not have to retract the mass of a relatively heavy motor.
In fact, if designed properly, you could proly have only the blade and its
bearing retract, along grooved guides of some sort, allowing for a very
rapid acceleration from whatever force is applied -- presumably springs?
But could also be pneumatic or hydraulic, or solenoidal.

Unless the deceleration of rotation is just an inherently faster process
than the retraction process.
But, from what I see, it seems the retraction is occurring FIRST, anyway, to
initiate the destructive crash, so mebbe the rotational issue is
irrelevant??

Now, if rotation is still an issue, wouldn't a caliper/rotor brake type deal
be as fast as his collision process, AND be non-destructive? Mebbe multiple
calipers.

Oh, oh, but then he wouldn't be able to sell new crumple ditties at
$70/pop.....

Mebbe you could run this by (G)ass, ask him to send me $5 if he likes the
idears. Or mebbe just invite me to one of them 'spensive luncheons, where
he's twisting CONgress's arms on safety'n'****, you know, for all the li'l
children....
--
EA