On Fri, 17 Dec 2004 22:06:55 GMT, "Frank Ketchum"
wrote:


"J. Clarke" wrote in message
...

One would hope that it doesn't fire if the saw is not spinning
(considering
that it has a computer onboard that's really not that hard to implement).

Right, except I don't recall seeing any sort of sensor which monitors
whether the blade is in motion or not. It looks like the only sensors are
the ones which detect a capacative change in the blade (ie, a finger or
hotdog touching it). It would also need to know if the blade is spinning or
not. This is why I believe the bypass switch is there. I of course am
uncertain which is why I raise the question in the first place.

Frank

IIRC there is a spinning blade sensor, a Hall effect thing. This is
discussed in some of the reports in the CPSC filings.

One of the reservations expressed by several of the testers was the
design and programming of the system. Apparently it's not up to the
standards expected of safety equipment.

(I was wrong, btw, to say that SawStop hadn't been tested. It was
tested by two engineering companies whose reports were attached to the
petition by SawStop, by the CPSC staff and by the manufacturers.)

What all the groups that tested SawStop agreed on -- with varying
degrees of vehemence -- is that it is a long way from being a
deployable product. The general consensus was that in its present
state it can't even be completely tested because so many of the
details haven't been reduced to production status.

After reading the descriptions I'd say what we've got here is closer
to a late-stage proof-of-principle device than a fully developed
prototype. I suspect this is the reason the manufacturers are so
unenthusasistic about putting it on table saws, although the very high
royalty doesn't help.

--RC


Projects expand to fill the clamps available -- plus 20 percent