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Steve Turner[_3_]

On 10/14/2010 2:29 PM, wrote:
On Thu, 14 Oct 2010 11:27:20 -0500, Steve Turner
wrote:

On 10/14/2010 11:15 AM, -MIKE- wrote:
On 10/14/10 6:39 AM, Steve Turner wrote:
Another reality check for all the people taking this thread off into the
wild blue yonder is the issue of getting the blade onto the arbor in the
presence of calipers that grip either side of the blade. My interest
(and Mike's as well, I think) in using a bicycle brake was simply a
matter of "how can I retrofit my existing table saw with a simple
convenience brake?" I think the wide-opening jaws of a bicycle brake
(maybe along with some kind of front-side cable disconnect to allow the
calipers to drop out of the way) would allow enough clearance to get the
blade on the arbor without too much trouble.

Heck, I think if it was mounted closer to the arbor than the edge, one pad on
the arbor side of the blade would be sufficient for a convenience slow/stop.

That very well could be true, and you could also use such a brake with dado
blades of any thickness... Interesting observation there Mike; I'm gonna have
to go do some peeking inside my Unisaw to see what the possibilities are. :-)
If you want to put a friction brake on a saw blade you need to do it
on the "non-blade" side of the arbour. Put the brake on the pulley if
belt drive, or the "fan end" of the motor if direct drive.

The only problem there is, if you stop the arbour too quickly the
arbour nut will wind off as the blade trys to keep spinning.
Same thing happens if DC injection on ann AC motor or
resistive(regenerative) braking on a DC motor is too harsh..

That's why the "saw stop" HAS to stop the blade directly. Stopping the
blade that fast through the arbour would inevitably wind the blade off
the arbour before the blade came to a safe stop.

Valid point, but again, we're not talking about a Saw-Stop equivalent here,
only a "convenience" brake that stops the blade in a second or two. Unless
you've dangerously under-tightened the arbor nut (or ridiculously
over-engineered the brake) that's not likely to cause enough centrifugal force
to loosen the arbor nut.

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