Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools in the
home workshop. Stationary grinders, table and radial arm circular saws
frequently turn abrasive or cutting disks that are directly mounted on the
motor's spindle. These disks have large inertial moments that allow them to
free wheel for a long time after the power is turned off. A lengthy coast to
complete stop often amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing

"HeyBub" wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools in
the home workshop. Stationary grinders, table and radial arm circular saws
frequently turn abrasive or cutting disks that are directly mounted on the
motor's spindle. These disks have large inertial moments that allow them
to free wheel for a long time after the power is turned off. A lengthy
coast to complete stop often amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing

Why did you find it???????????????

EXT wrote:
"HeyBub" wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting
tools in the home workshop. Stationary grinders, table and radial
arm circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."
http://www.homemetalshopclub.org/new...html#reversing

Why did you find it???????????????

I was looking for a home remedy for a festering, fulminating, giant red mass
on my, er, never mind. Just say I stumbled across it and thought it might be
interesting to some (the motor business, not my, um, temporary disability).

"HeyBub" wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools in
the home workshop. Stationary grinders, table and radial arm circular saws
frequently turn abrasive or cutting disks that are directly mounted on the
motor's spindle. These disks have large inertial moments that allow them
to free wheel for a long time after the power is turned off. A lengthy
coast to complete stop often amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a brake.
WW

On Sat, 09 Oct 2010 12:47:25 +0100, Stuart
wrote:

In article ,
HeyBub wrote:
I was looking for a home remedy for a festering, fulminating, giant red
mass on my, er, never mind.

A boil on the bum then :-)

Sounded like election-time talk to me. shrug

--
Ask not what the world needs. Ask what makes you come
alive... then go do it. Because what the world needs
is people who have come alive. -- Howard Thurman

WW wrote the following:
"HeyBub" wrote in message
...

Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools in
the home workshop. Stationary grinders, table and radial arm circular saws
frequently turn abrasive or cutting disks that are directly mounted on the
motor's spindle. These disks have large inertial moments that allow them
to free wheel for a long time after the power is turned off. A lengthy
coast to complete stop often amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a brake.
WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.

--

Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @

On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
"HeyBub" wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake,
under the table.... pads or rollers or whatever, that would squeeze the
blade.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On Sun, 10 Oct 2010 11:54:19 -0500, -MIKE-
wrote:

On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
"HeyBub" wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake,
under the table.... pads or rollers or whatever, that would squeeze the
blade.

Lawsuits from the arse with the SawStop patents notwithstanding, I
think he went with the positive stop style because it's the only one
which would keep from taking a finger off. The rest spin just enough
to do serious damage.

--
Ask not what the world needs. Ask what makes you come
alive... then go do it. Because what the world needs
is people who have come alive. -- Howard Thurman

On 10/10/10 4:51 PM, Larry Jaques wrote:
On Sun, 10 Oct 2010 11:54:19 -0500,
wrote:

On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake,
under the table.... pads or rollers or whatever, that would squeeze the
blade.

Lawsuits from the arse with the SawStop patents notwithstanding, I
think he went with the positive stop style because it's the only one
which would keep from taking a finger off. The rest spin just enough
to do serious damage.


A saw blade brake wouldn't infringe on SawStop's patent at all.



--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 10/10/2010 11:54 AM, -MIKE- wrote:
On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
"HeyBub" wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake, under the
table.... pads or rollers or whatever, that would squeeze the blade.

I've always wondered if a set of good quality bicycle brakes couldn't be safely
mounted on the trunnion to perform that very task. Route the cable to the
front of the saw to a hand or foot operated lever and there ya go.

--
Free bad advice available here.
To reply, eat the taco.
http://www.flickr.com/photos/bbqboyee/

"Steve Turner" wrote in message
...
On 10/10/2010 11:54 AM, -MIKE- wrote:
On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
"HeyBub" wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake,
under the
table.... pads or rollers or whatever, that would squeeze the blade.

I've always wondered if a set of good quality bicycle brakes couldn't be
safely mounted on the trunnion to perform that very task. Route the cable
to the front of the saw to a hand or foot operated lever and there ya go.

--
Free bad advice available here.
To reply, eat the taco.
http://www.flickr.com/photos/bbqboyee/

The now common disk brakes might be a great match - their designed to grab a
thin metal disk instead of a wide rim.
Kerry

On Sun, 10 Oct 2010 17:30:01 -0500, -MIKE-
wrote:

On 10/10/10 4:51 PM, Larry Jaques wrote:
On Sun, 10 Oct 2010 11:54:19 -0500,
wrote:

On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake,
under the table.... pads or rollers or whatever, that would squeeze the
blade.

Lawsuits from the arse with the SawStop patents notwithstanding, I
think he went with the positive stop style because it's the only one
which would keep from taking a finger off. The rest spin just enough
to do serious damage.


A saw blade brake wouldn't infringe on SawStop's patent at all.

WTF does that have to do with lawsuits? People sue to keep their
product on top whether they have a case or not. REAL WORLD, Mike.

--
Ask not what the world needs. Ask what makes you come
alive... then go do it. Because what the world needs
is people who have come alive. -- Howard Thurman

On 10/10/10 7:51 PM, Steve Turner wrote:
Someone could make some money by developing an aftermarket saw brake,
under the
table.... pads or rollers or whatever, that would squeeze the blade.

I've always wondered if a set of good quality bicycle brakes couldn't be
safely mounted on the trunnion to perform that very task. Route the
cable to the front of the saw to a hand or foot operated lever and there
ya go.


Interesting. There is certainly a lot for force against a bike brake
than a coasting saw blade/motor. I think a simple spring and
electromagnet/solenoid would do the trick in the same way an electric
door bell works.
No electric current: spring holds brakes closed.
Electric current: solenoid pulls brakes open.
A manual cable or secondary electric source could be added for manual
brake release.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 10/10/10 9:22 PM, Larry Jaques wrote:
On Sun, 10 Oct 2010 17:30:01 -0500,
wrote:

On 10/10/10 4:51 PM, Larry Jaques wrote:
On Sun, 10 Oct 2010 11:54:19 -0500,
wrote:

On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake,
under the table.... pads or rollers or whatever, that would squeeze the
blade.

Lawsuits from the arse with the SawStop patents notwithstanding, I
think he went with the positive stop style because it's the only one
which would keep from taking a finger off. The rest spin just enough
to do serious damage.


A saw blade brake wouldn't infringe on SawStop's patent at all.

WTF does that have to do with lawsuits? People sue to keep their
product on top whether they have a case or not. REAL WORLD, Mike.


In the "REAL WORLD" (relax, man), patent infringement law suits get
thrown out in the first hearing, too, Larry. What, you're a patent
attorney, too?


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

For fast stops a powered brake on may be preferred to normally brake on with
a spring setting the speed and strength to be held open all the time.


"-MIKE-" wrote in message
...
Interesting. There is certainly a lot for force against a bike brake
than a coasting saw blade/motor. I think a simple spring and
electromagnet/solenoid would do the trick in the same way an electric
door bell works.
No electric current: spring holds brakes closed.
Electric current: solenoid pulls brakes open.
A manual cable or secondary electric source could be added for manual
brake release.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 10/10/10 10:34 PM, Josepi wrote:
For fast stops a powered brake on may be preferred to normally brake on with
a spring setting the speed and strength to be held open all the time.


I would prefer powered off/normal on, because the operator would get
used to the blade always braking and in the case of a solenoid failure,
the blade would not coast.

I would also think an assembly with wheels applying just a little
pressure to the sides of the blade would make a decent passive system.
It would be just enough pressure to slow down the blade in a second or
two and not enough pressure for the motor to even register the resistance.

Think about how little pressure it takes with a scrap piece of wood to
stop a coasting blade.

--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

In article ,
says...

On 10/10/10 9:22 PM, Larry Jaques wrote:
On Sun, 10 Oct 2010 17:30:01 -0500,
wrote:

On 10/10/10 4:51 PM, Larry Jaques wrote:
On Sun, 10 Oct 2010 11:54:19 -0500,
wrote:

On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake,
under the table.... pads or rollers or whatever, that would squeeze the
blade.

Lawsuits from the arse with the SawStop patents notwithstanding, I
think he went with the positive stop style because it's the only one
which would keep from taking a finger off. The rest spin just enough
to do serious damage.


A saw blade brake wouldn't infringe on SawStop's patent at all.

WTF does that have to do with lawsuits? People sue to keep their
product on top whether they have a case or not. REAL WORLD, Mike.


In the "REAL WORLD" (relax, man), patent infringement law suits get
thrown out in the first hearing, too, Larry. What, you're a patent
attorney, too?

In any case, since EU law requires brakes already (indirectly, with an
allowed spindown time IIRC), Sawstop would have an uphill battle
claiming that they infringe its patents.

-MIKE- wrote:


I would prefer powered off/normal on, because the operator would get
used to the blade always braking and in the case of a solenoid
failure, the blade would not coast.

I would also think an assembly with wheels applying just a little
pressure to the sides of the blade would make a decent passive system.
It would be just enough pressure to slow down the blade in a second or
two and not enough pressure for the motor to even register the
resistance.
Think about how little pressure it takes with a scrap piece of wood to
stop a coasting blade.

Isn't there an old Indian trick about a spinning piece of wood and starting
a fire?

On Sun, 10 Oct 2010 21:41:24 -0500, -MIKE-
wrote:

On 10/10/10 9:22 PM, Larry Jaques wrote:

WTF does that have to do with lawsuits? People sue to keep their
product on top whether they have a case or not. REAL WORLD, Mike.


In the "REAL WORLD" (relax, man), patent infringement law suits get
thrown out in the first hearing, too, Larry. What, you're a patent
attorney, too?

No, I've just been horrified at how many frivolous lawsuits make it
into court, including patent infringement suits. Check it out.

--
Ask not what the world needs. Ask what makes you come
alive... then go do it. Because what the world needs
is people who have come alive. -- Howard Thurman

I would think that an emergency stop mechanism would be a whole different
magnitude than a scheduled, everyday, stop.

For a finger saver an emergency stop mechanism would have to stop the blade
in a few teeth passings. For everyday usage a couple dozen blade rotations
would be OK too. These two situations would require different tactics.

A dynamic electronic brake could vary the intensity for the two different
scenarios and we could add the caliper to the emerg stop. A caliper probably
wouldn't last long in everyday usage and would need to be adjusted and/or
replaced frequently.


"-MIKE-" wrote in message
...
I would prefer powered off/normal on, because the operator would get
used to the blade always braking and in the case of a solenoid failure,
the blade would not coast.

I would also think an assembly with wheels applying just a little
pressure to the sides of the blade would make a decent passive system.
It would be just enough pressure to slow down the blade in a second or
two and not enough pressure for the motor to even register the resistance.

Think about how little pressure it takes with a scrap piece of wood to
stop a coasting blade.

--

On 10/10/10 10:34 PM, Josepi wrote:
For fast stops a powered brake on may be preferred to normally brake on
with
a spring setting the speed and strength to be held open all the time.

I know of a fellow that worked on a vertical sliding saw professionally and
stopped it with the side of his thumb, for years. One day he got a carbide
blade installed and forgot.

The fire was in the last half of his thumb.


Watch your working habits. Environments change. You may too... in body
shape.



"HeyBub" wrote in message Isn't there an old Indian
trick about a spinning piece of wood and starting
a fire?


m...
-MIKE- wrote:


I would prefer powered off/normal on, because the operator would get
used to the blade always braking and in the case of a solenoid
failure, the blade would not coast.

I would also think an assembly with wheels applying just a little
pressure to the sides of the blade would make a decent passive system.
It would be just enough pressure to slow down the blade in a second or
two and not enough pressure for the motor to even register the
resistance.
Think about how little pressure it takes with a scrap piece of wood to
stop a coasting blade.

Josepi wrote:
I would think that an emergency stop mechanism would be a whole different
magnitude than a scheduled, everyday, stop.

indeed...

For a finger saver an emergency stop mechanism would have to stop the blade
in a few teeth passings. ...

SawStop is a few (10's of iirc) msec.

By several "tooth passings" a finger is already pretty well history...

--

On 10/11/10 12:13 AM, J. Clarke wrote:
In ,
says...

On 10/10/10 9:22 PM, Larry Jaques wrote:
On Sun, 10 Oct 2010 17:30:01 -0500,
wrote:

On 10/10/10 4:51 PM, Larry Jaques wrote:
On Sun, 10 Oct 2010 11:54:19 -0500,
wrote:

On 10/10/10 11:35 AM, willshak wrote:
WW wrote the following:
wrote in message
...
Found this article...

"Single-phase induction motors drive many arbor-mounted cutting tools
in the home workshop. Stationary grinders, table and radial arm
circular saws frequently turn abrasive or cutting disks that are
directly mounted on the motor's spindle. These disks have large
inertial moments that allow them to free wheel for a long time after
the power is turned off. A lengthy coast to complete stop often
amounts to a major inconvenience."

http://www.homemetalshopclub.org/new...html#reversing


Great ... I may rig up my table saw this way. Would be safer with a
brake. WW

If I need to stop a spinning table saw blade in a hurry to change or
reset something, I find that a scrap piece of lumber makes a great blade
brake. Turn the saw off and slide the scrap up to the still spinning
blade. Blade stops in a couple of seconds. No extra parts needed.


Someone could make some money by developing an aftermarket saw brake,
under the table.... pads or rollers or whatever, that would squeeze the
blade.

Lawsuits from the arse with the SawStop patents notwithstanding, I
think he went with the positive stop style because it's the only one
which would keep from taking a finger off. The rest spin just enough
to do serious damage.


A saw blade brake wouldn't infringe on SawStop's patent at all.

WTF does that have to do with lawsuits? People sue to keep their
product on top whether they have a case or not. REAL WORLD, Mike.


In the "REAL WORLD" (relax, man), patent infringement law suits get
thrown out in the first hearing, too, Larry. What, you're a patent
attorney, too?

In any case, since EU law requires brakes already (indirectly, with an
allowed spindown time IIRC), Sawstop would have an uphill battle
claiming that they infringe its patents.


Especially since it's apples and oranges.
SawStop is a safety brake that only stops when contact with flesh is
made, and it's instantaneous.
I'm talking about a gradual brake that occurs as part of normal operation.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 10/11/10 7:11 AM, HeyBub wrote:
-MIKE- wrote:


I would prefer powered off/normal on, because the operator would get
used to the blade always braking and in the case of a solenoid
failure, the blade would not coast.

I would also think an assembly with wheels applying just a little
pressure to the sides of the blade would make a decent passive system.
It would be just enough pressure to slow down the blade in a second or
two and not enough pressure for the motor to even register the
resistance.
Think about how little pressure it takes with a scrap piece of wood to
stop a coasting blade.

Isn't there an old Indian trick about a spinning piece of wood and starting
a fire?


Point?


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 10/11/10 9:01 AM, Larry Jaques wrote:
On Sun, 10 Oct 2010 21:41:24 -0500,
wrote:

On 10/10/10 9:22 PM, Larry Jaques wrote:

WTF does that have to do with lawsuits? People sue to keep their
product on top whether they have a case or not. REAL WORLD, Mike.


In the "REAL WORLD" (relax, man), patent infringement law suits get
thrown out in the first hearing, too, Larry. What, you're a patent
attorney, too?

No, I've just been horrified at how many frivolous lawsuits make it
into court, including patent infringement suits. Check it out.


I understand and it is certainly frustrating.
But, if we let that deter us, not one would ever invent anything.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

In article , says...

I would think that an emergency stop mechanism would be a whole different
magnitude than a scheduled, everyday, stop.

For a finger saver an emergency stop mechanism would have to stop the blade
in a few teeth passings. For everyday usage a couple dozen blade rotations
would be OK too. These two situations would require different tactics.

A dynamic electronic brake could vary the intensity for the two different
scenarios and we could add the caliper to the emerg stop. A caliper probably
wouldn't last long in everyday usage and would need to be adjusted and/or
replaced frequently.

So how much power do you have to put into that electronic brake to stop
the blade as fast as Sawstop's physical block?

And why would a caliper not last long? A set of brake pads on a car
with 10" rotors lasts 40,000 miles or so, and they're getting a Hell of
a lot more of a workout that they would stopping a little bitty saw
blade that masses less than 1/1000 as much.



"-MIKE-" wrote in message
...
I would prefer powered off/normal on, because the operator would get
used to the blade always braking and in the case of a solenoid failure,
the blade would not coast.

I would also think an assembly with wheels applying just a little
pressure to the sides of the blade would make a decent passive system.
It would be just enough pressure to slow down the blade in a second or
two and not enough pressure for the motor to even register the resistance.

Think about how little pressure it takes with a scrap piece of wood to
stop a coasting blade.

In article ,
says...

Josepi wrote:
I would think that an emergency stop mechanism would be a whole different
magnitude than a scheduled, everyday, stop.

indeed...

For a finger saver an emergency stop mechanism would have to stop the blade
in a few teeth passings. ...

SawStop is a few (10's of iirc) msec.

By several "tooth passings" a finger is already pretty well history...

Sawstop stops the blade in 1/200 of a second, according to their Web
site. At 3450 RPM that means the blade stops in .29 revolution, which
with a 60 tooth blade means that 17 teeth have had a shot at your
finger.

On 10/11/10 12:08 PM, J. Clarke wrote:
In ,
says...

Josepi wrote:
I would think that an emergency stop mechanism would be a whole different
magnitude than a scheduled, everyday, stop.

indeed...

For a finger saver an emergency stop mechanism would have to stop the blade
in a few teeth passings. ...

SawStop is a few (10's of iirc) msec.

By several "tooth passings" a finger is already pretty well history...

Sawstop stops the blade in 1/200 of a second, according to their Web
site. At 3450 RPM that means the blade stops in .29 revolution, which
with a 60 tooth blade means that 17 teeth have had a shot at your
finger.


That may be true, but they still don't do any harm.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

-MIKE- wrote:
On 10/11/10 7:11 AM, HeyBub wrote:
-MIKE- wrote:


I would prefer powered off/normal on, because the operator would get
used to the blade always braking and in the case of a solenoid
failure, the blade would not coast.

I would also think an assembly with wheels applying just a little
pressure to the sides of the blade would make a decent passive
system. It would be just enough pressure to slow down the blade in
a second or two and not enough pressure for the motor to even
register the resistance.
Think about how little pressure it takes with a scrap piece of wood
to stop a coasting blade.

Isn't there an old Indian trick about a spinning piece of wood and
starting a fire?


Point?

Everybody knows that, which is why I'm trying to explain. But everyone's
alive except those who drowned in an adjacent bog.

On 10/11/10 3:05 PM, HeyBub wrote:
-MIKE- wrote:
On 10/11/10 7:11 AM, HeyBub wrote:
-MIKE- wrote:


I would prefer powered off/normal on, because the operator would get
used to the blade always braking and in the case of a solenoid
failure, the blade would not coast.

I would also think an assembly with wheels applying just a little
pressure to the sides of the blade would make a decent passive
system. It would be just enough pressure to slow down the blade in
a second or two and not enough pressure for the motor to even
register the resistance.
Think about how little pressure it takes with a scrap piece of wood
to stop a coasting blade.

Isn't there an old Indian trick about a spinning piece of wood and
starting a fire?


Point?

Everybody knows that, which is why I'm trying to explain. But everyone's
alive except those who drowned in an adjacent bog.


Put down the pipe. :-p


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

J. Clarke wrote:
In , says...

I would think that an emergency stop mechanism would be a whole different
magnitude than a scheduled, everyday, stop.

For a finger saver an emergency stop mechanism would have to stop the blade
in a few teeth passings. For everyday usage a couple dozen blade rotations
would be OK too. These two situations would require different tactics.

A dynamic electronic brake could vary the intensity for the two different
scenarios and we could add the caliper to the emerg stop. A caliper probably
wouldn't last long in everyday usage and would need to be adjusted and/or
replaced frequently.

So how much power do you have to put into that electronic brake to stop
the blade as fast as Sawstop's physical block?

And why would a caliper not last long? A set of brake pads on a car
with 10" rotors lasts 40,000 miles or so, and they're getting a Hell of
a lot more of a workout that they would stopping a little bitty saw
blade that masses less than 1/1000 as much.

The physics on that seem interesting. A little like stopping a speeding
bullet on a dime--it challenges my imagination. Probably not quite as
difficult as stopping a lightning bolt, but I wouldn't want to try that
either.

Bill

17 teeth?

How fast can you push your finger?



"-MIKE-" wrote in message
...
That may be true, but they still don't do any harm.



Sawstop stops the blade in 1/200 of a second, according to their Web
site. At 3450 RPM that means the blade stops in .29 revolution, which
with a 60 tooth blade means that 17 teeth have had a shot at your
finger.



--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

Have you seen the videos and live demonstration? It does no harm.
They wouldn't be selling like hotcakes if their marketing strategy
centered around "losing only a pint of blood, instead of a whole finger."
Have you seen the video demonstrations? They've been done with lunch
meat and human fingers.

17 teeth?

How fast can you push your finger?

wrote in message

That may be true, but they still don't do any harm.

Sawstop stops the blade in 1/200 of a second, according to their Web
site. At 3450 RPM that means the blade stops in .29 revolution, which
with a 60 tooth blade means that 17 teeth have had a shot at your
finger.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 10/12/2010 11:04 AM, -MIKE- wrote:
Have you seen the videos and live demonstration? It does no harm.
They wouldn't be selling like hotcakes if their marketing strategy
centered around "losing only a pint of blood, instead of a whole finger."
Have you seen the video demonstrations? They've been done with lunch
meat and human fingers.

17 teeth?

How fast can you push your finger?

wrote in message

That may be true, but they still don't do any harm.

Sawstop stops the blade in 1/200 of a second, according to their Web
site. At 3450 RPM that means the blade stops in .29 revolution, which
with a 60 tooth blade means that 17 teeth have had a shot at your
finger.

And with a 60-tooth blade spinning at 3450 RPM, that's 3450 teeth spinning past
every *second*. At that speed, coming to a dead stop after only 17 teeth have
had a chance to cut anything is pretty damn good. Unless you're just flat-out
careless or stupid (or both) and are wildly advancing your fingers towards the
blade, 17 teeth are not going to do much damage. I could do much worse in the
blink of an eye with a careless swipe of my pocketknife.

--
See Nad. See Nad go. Go Nad!
To reply, eat the taco.
http://www.flickr.com/photos/bbqboyee/

On 10/12/10 11:21 AM, Steve Turner wrote:
On 10/12/2010 11:04 AM, -MIKE- wrote:
Have you seen the videos and live demonstration? It does no harm.
They wouldn't be selling like hotcakes if their marketing strategy
centered around "losing only a pint of blood, instead of a whole finger."
Have you seen the video demonstrations? They've been done with lunch
meat and human fingers.

17 teeth?

How fast can you push your finger?

wrote in message

That may be true, but they still don't do any harm.

Sawstop stops the blade in 1/200 of a second, according to their Web
site. At 3450 RPM that means the blade stops in .29 revolution, which
with a 60 tooth blade means that 17 teeth have had a shot at your
finger.

And with a 60-tooth blade spinning at 3450 RPM, that's 3450 teeth
spinning past every *second*. At that speed, coming to a dead stop after
only 17 teeth have had a chance to cut anything is pretty damn good.
Unless you're just flat-out careless or stupid (or both) and are wildly
advancing your fingers towards the blade, 17 teeth are not going to do
much damage. I could do much worse in the blink of an eye with a
careless swipe of my pocketknife.


I've seen a hotdog demonstration in which they *did* push the dog, on
top of a piece of wood, into the blade as quick as the blade with
receive it. It was much faster than anyone with any sense would advance
any stock into a table saw. The dog had the tiniest little sliver of
"skin" taken off. Had it been a finger, it would surely have bled a drop
or two. But I've done much worse to my finger when a file slipped or I
got a splinter.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

This was exactly my point.

The other thing, and unfair to the 17 teeth is OK defence is that the
SawStop pulls the blade away and down. It appears to be grabbed on the back
side of the blade and the inertia pulls the balde back and under the table
effectively removing the blade from the finger area. I doubt you would want
to do this everytime in a **NON**emergency stop. My guess is arbor bending
would set in after a few dozen of them.

Watch the videos (most have). This is no gentle stop for an armature and saw
blade of that intertia.

So the retort to the 17 teeth big damage people is still "How fast do you
push your finger?"

OTOH: Pushing the stock, slipping off, and back handing a running blade can
be different speeds.


"-MIKE-" wrote in message
...
I've seen a hotdog demonstration in which they *did* push the dog, on
top of a piece of wood, into the blade as quick as the blade with
receive it. It was much faster than anyone with any sense would advance
any stock into a table saw. The dog had the tiniest little sliver of
"skin" taken off. Had it been a finger, it would surely have bled a drop
or two. But I've done much worse to my finger when a file slipped or I
got a splinter.


--

On 10/12/10 12:13 PM, Josepi wrote:
This was exactly my point.

The other thing, and unfair to the 17 teeth is OK defence is that the
SawStop pulls the blade away and down. It appears to be grabbed on the back
side of the blade and the inertia pulls the balde back and under the table
effectively removing the blade from the finger area. I doubt you would want
to do this everytime in a **NON**emergency stop. My guess is arbor bending
would set in after a few dozen of them.

Watch the videos (most have). This is no gentle stop for an armature and saw
blade of that intertia.

So the retort to the 17 teeth big damage people is still "How fast do you
push your finger?"

OTOH: Pushing the stock, slipping off, and back handing a running blade can
be different speeds.


I guess I don't know what we're debating, anymore.
I thought we were talking about slowing down the coast of a saw blade
after turning off the power. I guess we got on a tangent.

If it's you're mission to dream up ways to refute the effectiveness of
the SawStop technology... well, I'm off the boat, because you've lost
your mind. :-)


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

LOL..I guess I am in the same boat as you. I did jump in late and saw (pun)
some twist about emerg. stopping the blade. Then I jumped in to point out a
difference in technique would be needed and got some resistance. Now I am
chatting with you and who knows whwre it went.

I am not disputing the effectiveness of the SawStop, at all. After seeing
videos I feel I owe the guy something without buying one. Amazing design.
Now I want to kno how to beat it with my wallet.

BTW: never owned a table saw and have never intended to. I know too many
that have lost an eye, fingers, thumb pieces and a **dog to one. When I wave
to somebody I don't want them to think I am giving them the one finger
salute.

**(j/k about the dog...LOL)



"-MIKE-" wrote in message
...
I guess I don't know what we're debating, anymore.
I thought we were talking about slowing down the coast of a saw blade
after turning off the power. I guess we got on a tangent.

If it's you're mission to dream up ways to refute the effectiveness of
the SawStop technology... well, I'm off the boat, because you've lost
your mind. :-)


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On Tue, 12 Oct 2010 11:28:12 -0400, "Josepi"
wrote:


17 teeth?

How fast can you push your finger?



"-MIKE-" wrote in message
...
That may be true, but they still don't do any harm.



Sawstop stops the blade in 1/200 of a second, according to their Web
site. At 3450 RPM that means the blade stops in .29 revolution, which
with a 60 tooth blade means that 17 teeth have had a shot at your
finger.

Actually significantly LESS than 17 teeth, because the blade is very
quickly slowing down throughout that 1/200 of a second. I believe the
number is something like SEVEN teeth pass the gullet from the time of
contact to full stop, and the last 3 or 4 are pretty well stopped as
they go by.
A demonstation showed a damp peice of cardboard stop the saw with
barely a nick in it.

On Mon, 11 Oct 2010 19:59:30 -0400, Bill wrote:

J. Clarke wrote:
In , says...

I would think that an emergency stop mechanism would be a whole different
magnitude than a scheduled, everyday, stop.

For a finger saver an emergency stop mechanism would have to stop the blade
in a few teeth passings. For everyday usage a couple dozen blade rotations
would be OK too. These two situations would require different tactics.

A dynamic electronic brake could vary the intensity for the two different
scenarios and we could add the caliper to the emerg stop. A caliper probably
wouldn't last long in everyday usage and would need to be adjusted and/or
replaced frequently.

So how much power do you have to put into that electronic brake to stop
the blade as fast as Sawstop's physical block?

And why would a caliper not last long? A set of brake pads on a car
with 10" rotors lasts 40,000 miles or so, and they're getting a Hell of
a lot more of a workout that they would stopping a little bitty saw
blade that masses less than 1/1000 as much.

The physics on that seem interesting. A little like stopping a speeding
bullet on a dime--it challenges my imagination. Probably not quite as
difficult as stopping a lightning bolt, but I wouldn't want to try that
either.

Bill
No way a caliper could stop the blade in even 4X the time the
saw-stop does. And keeping dust out of the gap between tha "pad" and
the blade would be quite problematic - with dust decreasing the
stopping efficiency by a very large margin.