sp

saulgoode

27/07/2008 11:12 AM

Table Saw Arbor Question

Classic issue with the table saw arbor: Pop got this dado blade, and
guess what -- the arbor won't fit the blade. Doh!

So we're looking at it, figuring we'll need to buy either a different
sort of blade, or buy a whole new table saw setup, and got to
wondering if there's a way to easily retrofit a longer arber on your
table saw without having to buythe whole damned thing again.

Thoughts?


- Saul


This topic has 17 replies

BB

Bored Borg

in reply to saulgoode on 27/07/2008 11:12 AM

21/08/2008 6:33 PM

So, let's see if I have this straight:

Here in Europe, the law decrees that we're not allowed to fit dado sets to
table saws because that'd be dangerous.

Does that mean that it's _safe_ in the good ol' USA?

if I decide to take up smoking (Heaven forbid!!) should I cross the Atlantic
first so it won't harm me? Oops, smokings dangerous there too, I hear. Scrub
that. O.K. age of consent, beer drinking, age to drive a car... buying
ephedrine... blah blah You get the philosophical nuance, I'm sure. Up to
around 1938 Marijuana was a frowned-upon eccentricity, but not actually
dangerous. After that, one puff would lead to reefer madness and you'd murder
your sister.

A parallel -
It was only pressure group intervention that stopped the U,K. government
legislating in compulsory leg-fairings and, er, _seatbelts_ for motorcycles.
That got modified, but the restrictive thinking led to severe horsepower
ratings for learners - which meant machines that were too slow to keep up
with car traffic unless carburetted to be thrashed out of the tractability
power bandwidth. Inexperienced riders were forced to handle a machine with a
vertical no-go to full-power throttle response because some idiot had
legislated that this would be "safer" than allowing him to have access to a
bit of soft, controllable torque..
Šfor example.


Is, or is not, the practice of fitting dado blades to table saws actually
dangerous?

Opinions, please, gentlefolk.

BB

Bored Borg

in reply to saulgoode on 27/07/2008 11:12 AM

22/08/2008 5:53 PM

On Thu, 21 Aug 2008 19:15:58 +0100, J. Clarke wrote
(in article <[email protected]>):

> Bored Borg wrote:

<specious waffle expurgated to obviate tedium>

> If you check again I think you'll find that the law or regulation
> places an upper limit on spin-down time after powerdown, and the added
> mass of a dado blade takes the spin-down time beyond what the
> regulations allow unless the saw has a blade brake. I don't think
> you'll find any objection to a dado blade on a saw with a blade brake.
>

I was taking that for granted, My point of irony _included_, and was
essentially about, the definition of protracted spin-down time being
dangerous and was the whole point of the query, hence my asking for opinion
on that very issue.

THAT was the very issue you ducked out of answering.

I think most people spotted that :-)

It's very hard explaining to someone how to "get" a joke. Maybe I'll wear a
red nose next time. (insert emoticon of limey wearing red nose and baggy
pants with a custard pie down his shorts)

>>Šbut the restrictive
>> thinking led to severe horsepower ratings for learners - which meant
>> machines that were too slow to keep up with car traffic unless
>> carburetted to be thrashed out of the tractability power bandwidth.
>> Inexperienced riders were forced to handle a machine with a vertical
>> no-go to full-power throttle response because some idiot had
>> legislated that this would be "safer" than allowing him to have
>> access to a bit of soft, controllable torque..
>> Šfor example.

<pompous waffle expurgated to prevent reader self-harm>
>
> Would you care to explain how a horsepower limit results in this
> situation? And how does being "carburetted to be thrashed out of the
> tractability power bandwidth" allow a motorcycle with a given amount
> of horsepower to keep up with traffic when one with the same
> horsepower but twice the displacement cannot do so?

Ok, I obviously explained this rather badly.

The tractability thing is all about torque, not horses gained from high rpm.
If you have, say, a 1200cc motor (convert it yourself, but I think it's 74
cubes) running at low revs, it may well produce the same bhp as a 200cc motor
running at higher revs, but the torque will be very much greater.

In practical terms, this means that the big motor will produce _usable_ power
throughout its rev range while the small engine needs to be revved to near
its limit to, say, prevent stalling or to produce "acceleration" (used in the
popular rather than the "scientific" sense - I note that there are pedants
about.) An inexperienced rider is therefore presented with a throttle control
which turns under his hand with no appreciable effect on the road until
suddenly, the usable power cuts it like throwing a switch.
Contrast that with the smooth and predictable power available from the
bigger, slower-revving engine where the relationship between throttle
position and road speed is (perceptibly) linear.

A 125cc 10 bhp will typically need to be revved to (guessing) 10-14000 rpm to
produce the same road speed as a 60 horse motor ticking away at (again
guessing - don't pick a fight over the exact figures) 2 or 3 thousand rpm.
The low displacement motor needs very precise gear-stick dancing to keep it
running in its usable power range. If the revs drop as traffic speed drops,
power will not be available to keep up with the next increase in mean traffic
speed unless the motor is revved back into its power band and the rider
controls road speed with the gears. A bigger engine can just be tailed off
and picked up again on the throttle.

This relationship breaks down as one begins to approach the speed of light,
of course, which makes it harder to draw graphs in crayons of only one
colour.

The point I _thought_ I was making was that U.K. legislation has decreed that
inexperienced riders must use machines which really need more experience to
drive safely on the road than the bigger machines that they are banned from
using.

Therefore, legislation is not the arbiter of truth.

>
>> Is, or is not, the practice of fitting dado blades to table saws
>> actually dangerous?
>>
>> Opinions, please, gentlefolk.
>
> Not gonna touch that one.

Come on, you like to prod me on the side-issues - have the courage to answer
the question :-)

Pp

Puckdropper

in reply to saulgoode on 27/07/2008 11:12 AM

28/07/2008 4:13 AM

saulgoode <[email protected]> wrote in
news:878f6c2c-8f76-4902-9381-dae4f07dcd8e@m44g2000hsc.googlegroups.com:


> I'm in the USA, using a generic Craftsman (don't say it), but really
> this is just a general question. I figured the spindle length length
> was based on some sort of work function for the motor, but wanted to
> see if there was some simple way to upgrade an existing saw.
>
> I also figured "no" was the default answer, but wanted to see if there
> was some secret out there I didn't know about.
>
> - Saul
>

Take your saw's model number to Sears and ask. My Craftsman TS had a
short shaft, but a dado insert plate was included (perhaps clueless
marketing at it again?)

While you're out, you may want to look in to routers and straight bits...
Sometimes it's easier to cut dadoes with the router than it is the saw.

Puckdropper
--
If you're quiet, your teeth never touch your ankles.

To email me directly, send a message to puckdropper (at) fastmail.fm

MD

Morris Dovey

in reply to saulgoode on 27/07/2008 11:12 AM

21/08/2008 1:11 PM

Bored Borg wrote:

> Is, or is not, the practice of fitting dado blades to table saws actually
> dangerous?
>
> Opinions, please, gentlefolk.

IMO, the danger - and/or the safety - is determined by the user.
Personally, I prefer table to radial arm saw for dadoing with a saw -
but I prefer a router to either saw.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

TV

Tom Veatch

in reply to saulgoode on 27/07/2008 11:12 AM

21/08/2008 2:34 PM

On Thu, 21 Aug 2008 18:33:30 +0100, Bored Borg
<[email protected]> wrote:

>Is, or is not, the practice of fitting dado blades to table saws actually
>dangerous?
>
>Opinions, please, gentlefolk.


My opinion, for what it's worth, is that, all other things being
equal, using a dado blade on a table saw is less dangerous than using
a "regular" saw blade - buried cut with no sharp spinning objects
exposed to nip unwary fingers, according to some, less danger of
kickback, etc. But it all comes down to the operator. Unsafe
procedures will bite regardless of the type of blade.

I believe, as said elsewhere, the European (all countries?)
restrictions are due to the spin down time. Without some form of
braking, a full width stacked dado takes significantly longer to come
to a stop than a "regular" blade.,

Tom Veatch
Wichita, KS
USA

Uu

"Upscale"

in reply to saulgoode on 27/07/2008 11:12 AM

22/08/2008 12:18 PM


"Leon" <[email protected]> wrote in message
> > Does that mean that it's _safe_ in the good ol' USA?
>
> Exactly right! Apparently some people are less prone to accidents or
> getting sick. If you live in California you are much more prone to
getting
> cancer if you cook out doors with charcoal.

Guess that's better than cooking indoors with charcoal and choking to death.

sp

saulgoode

in reply to saulgoode on 27/07/2008 11:12 AM

27/07/2008 3:04 PM

On Jul 27, 2:50=A0pm, "J. Clarke" <[email protected]> wrote:
> Edwin Pawlowski wrote:
> > "saulgoode" <[email protected]> wrote in message
> >news:[email protected]...
> >> Classic issue with the table saw arbor: Pop got this dado blade,
> >> and
> >> guess what -- the arbor won't fit the blade. Doh!
>
> >> So we're looking at it, figuring we'll need to buy either a
> >> different
> >> sort of blade, or buy a whole new table saw setup, and got to
> >> wondering if there's a way to easily retrofit a longer arber on
> >> your
> >> table saw without having to buythe whole damned thing again.
>
> >> Thoughts?
>
> >> - Saul
>
> > You don't say what model saw you have, but chances are the arbor is
> > not long enough because the saw is not powerful enough to properly
> > turn a dado blade. A 1 1/2 HP contractor saw can easily turn an 8"
> > dado, but some benchtops struggle with a 6".
>
> He doesn't say where he is. =A0In the EU I understand that there is a
> legal issue with regard to some regulation or other regarding
> spin-down time--they make the saws with arbors intended specifically
> to prevent the use of a dado because the added mass of the dado
> increases the spin-down time beyond what the government allows.
>
> --
> --
> --John
> to email, dial "usenet" and validate
> (was jclarke at eye bee em dot net)- Hide quoted text -
>
> - Show quoted text -

I'm in the USA, using a generic Craftsman (don't say it), but really
this is just a general question. I figured the spindle length length
was based on some sort of work function for the motor, but wanted to
see if there was some simple way to upgrade an existing saw.

I also figured "no" was the default answer, but wanted to see if there
was some secret out there I didn't know about.

- Saul

sp

saulgoode

in reply to saulgoode on 27/07/2008 11:12 AM

18/08/2008 9:29 AM

On Jul 28, 8:54=A0am, "Leon" <[email protected]> wrote:
> "Puckdropper" <puckdropper(at)yahoo(dot)com> wrote in message
>
> news:[email protected]...
>
> > saulgoode <[email protected]> wrote in
> >news:878f6c2c-8f76-4902-9381-dae4f07dcd8e@m44g2000hsc.googlegroups.com:
>
> > Take your saw's model number to Sears and ask. =A0My Craftsman TS had a
> > short shaft, but a dado insert plate was included (perhaps clueless
> > marketing at it again?)
>
> With that they wil popbably point him towards the wobble dado blade that
> they market, =A0It is narrower than the typical fully loaded stacked dado=
set.

Thanks, guys. This was exactly the case -- change the dado blade type,
not the motor on the saw, spot on. I haven't used the wobble, but my
Pop has. I'll ask him if he likes it; I'm a little skeptical about it.

I currently use my router for dados (I was smart enough to get a 1/2"
collared router), but I wanted to try the table saw just to compare
techniques. Guess I'll stick that dado blade in the toolbox for when I
eventually upgrade my table saw, eh.

- Saul

EP

"Edwin Pawlowski"

in reply to saulgoode on 27/07/2008 11:12 AM

27/07/2008 3:18 PM


"saulgoode" <[email protected]> wrote in message
news:[email protected]...
> Classic issue with the table saw arbor: Pop got this dado blade, and
> guess what -- the arbor won't fit the blade. Doh!
>
> So we're looking at it, figuring we'll need to buy either a different
> sort of blade, or buy a whole new table saw setup, and got to
> wondering if there's a way to easily retrofit a longer arber on your
> table saw without having to buythe whole damned thing again.
>
> Thoughts?
>
>
> - Saul

You don't say what model saw you have, but chances are the arbor is not long
enough because the saw is not powerful enough to properly turn a dado blade.
A 1 1/2 HP contractor saw can easily turn an 8" dado, but some benchtops
struggle with a 6".

Lr

"Leon"

in reply to saulgoode on 27/07/2008 11:12 AM

28/07/2008 8:54 AM


"Puckdropper" <puckdropper(at)yahoo(dot)com> wrote in message
news:[email protected]...
> saulgoode <[email protected]> wrote in
> news:878f6c2c-8f76-4902-9381-dae4f07dcd8e@m44g2000hsc.googlegroups.com:
>
> Take your saw's model number to Sears and ask. My Craftsman TS had a
> short shaft, but a dado insert plate was included (perhaps clueless
> marketing at it again?)

With that they wil popbably point him towards the wobble dado blade that
they market, It is narrower than the typical fully loaded stacked dado set.




EP

"Edwin Pawlowski"

in reply to saulgoode on 27/07/2008 11:12 AM

21/08/2008 3:17 PM


"Bored Borg" <[email protected]> wrote in message
news:[email protected]...
> So, let's see if I have this straight:
>
> Here in Europe, the law decrees that we're not allowed to fit dado sets to
> table saws because that'd be dangerous.
>
> Does that mean that it's _safe_ in the good ol' USA?
>


Why yes, of course that is exactly what it means. Not only are we more
refined and dignified, we are more conscientious and skilled at operating
complex machinery. And our beer is colder too.

MJ

Mark & Juanita

in reply to saulgoode on 27/07/2008 11:12 AM

22/08/2008 7:23 PM

Leon wrote:

>
> "Bored Borg" <[email protected]> wrote in message
> news:[email protected]...
>> So, let's see if I have this straight:
>>
>> Here in Europe, the law decrees that we're not allowed to fit dado sets
>> to table saws because that'd be dangerous.
>>
>> Does that mean that it's _safe_ in the good ol' USA?
>
>
> Exactly right! Apparently some people are less prone to accidents or
> getting sick. If you live in California you are much more prone to
> getting cancer if you cook out doors with charcoal.

In California, you are prone to get cancer when you buy and use darn near
anything.

--
If you're going to be dumb, you better be tough

JC

"J. Clarke"

in reply to saulgoode on 27/07/2008 11:12 AM

27/07/2008 3:50 PM

Edwin Pawlowski wrote:
> "saulgoode" <[email protected]> wrote in message
> news:[email protected]...
>> Classic issue with the table saw arbor: Pop got this dado blade,
>> and
>> guess what -- the arbor won't fit the blade. Doh!
>>
>> So we're looking at it, figuring we'll need to buy either a
>> different
>> sort of blade, or buy a whole new table saw setup, and got to
>> wondering if there's a way to easily retrofit a longer arber on
>> your
>> table saw without having to buythe whole damned thing again.
>>
>> Thoughts?
>>
>>
>> - Saul
>
> You don't say what model saw you have, but chances are the arbor is
> not long enough because the saw is not powerful enough to properly
> turn a dado blade. A 1 1/2 HP contractor saw can easily turn an 8"
> dado, but some benchtops struggle with a 6".

He doesn't say where he is. In the EU I understand that there is a
legal issue with regard to some regulation or other regarding
spin-down time--they make the saws with arbors intended specifically
to prevent the use of a dado because the added mass of the dado
increases the spin-down time beyond what the government allows.



--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

JC

"J. Clarke"

in reply to saulgoode on 27/07/2008 11:12 AM

21/08/2008 2:15 PM

Bored Borg wrote:
> So, let's see if I have this straight:
>
> Here in Europe, the law decrees that we're not allowed to fit dado
> sets to table saws because that'd be dangerous.

If you check again I think you'll find that the law or regulation
places an upper limit on spin-down time after powerdown, and the added
mass of a dado blade takes the spin-down time beyond what the
regulations allow unless the saw has a blade brake. I don't think
you'll find any objection to a dado blade on a saw with a blade brake.

> Does that mean that it's _safe_ in the good ol' USA?
>
> if I decide to take up smoking (Heaven forbid!!) should I cross the
> Atlantic first so it won't harm me? Oops, smokings dangerous there
> too, I hear. Scrub that. O.K. age of consent, beer drinking, age to
> drive a car... buying ephedrine... blah blah You get the
> philosophical nuance, I'm sure. Up to around 1938 Marijuana was a
> frowned-upon eccentricity, but not actually dangerous. After that,
> one puff would lead to reefer madness and you'd murder your sister.
>
> A parallel -
> It was only pressure group intervention that stopped the U,K.
> government legislating in compulsory leg-fairings and, er,
> _seatbelts_ for motorcycles. That got modified, but the restrictive
> thinking led to severe horsepower ratings for learners - which meant
> machines that were too slow to keep up with car traffic unless
> carburetted to be thrashed out of the tractability power bandwidth.
> Inexperienced riders were forced to handle a machine with a vertical
> no-go to full-power throttle response because some idiot had
> legislated that this would be "safer" than allowing him to have
> access to a bit of soft, controllable torque..
> Šfor example.

Would you care to explain how a horsepower limit results in this
situation? And how does being "carburetted to be thrashed out of the
tractability power bandwidth" allow a motorcycle with a given amount
of horsepower to keep up with traffic when one with the same
horsepower but twice the displacement cannot do so?

> Is, or is not, the practice of fitting dado blades to table saws
> actually dangerous?
>
> Opinions, please, gentlefolk.

Not gonna touch that one.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

JC

"J. Clarke"

in reply to saulgoode on 27/07/2008 11:12 AM

22/08/2008 4:42 PM

Bored Borg wrote:
> On Thu, 21 Aug 2008 19:15:58 +0100, J. Clarke wrote
> (in article <[email protected]>):
>
>> Bored Borg wrote:
>
> <specious waffle expurgated to obviate tedium>
>
>> If you check again I think you'll find that the law or regulation
>> places an upper limit on spin-down time after powerdown, and the
>> added mass of a dado blade takes the spin-down time beyond what the
>> regulations allow unless the saw has a blade brake. I don't think
>> you'll find any objection to a dado blade on a saw with a blade
>> brake.
>>
>
> I was taking that for granted, My point of irony _included_, and
> was
> essentially about, the definition of protracted spin-down time being
> dangerous and was the whole point of the query, hence my asking for
> opinion on that very issue.
>
> THAT was the very issue you ducked out of answering.
>
> I think most people spotted that :-)
>
> It's very hard explaining to someone how to "get" a joke. Maybe I'll
> wear a red nose next time. (insert emoticon of limey wearing red
> nose
> and baggy pants with a custard pie down his shorts)
>
>>> Šbut the restrictive
>>> thinking led to severe horsepower ratings for learners - which
>>> meant
>>> machines that were too slow to keep up with car traffic unless
>>> carburetted to be thrashed out of the tractability power
>>> bandwidth.
>>> Inexperienced riders were forced to handle a machine with a
>>> vertical
>>> no-go to full-power throttle response because some idiot had
>>> legislated that this would be "safer" than allowing him to have
>>> access to a bit of soft, controllable torque..
>>> Šfor example.
>
> <pompous waffle expurgated to prevent reader self-harm>
>>
>> Would you care to explain how a horsepower limit results in this
>> situation? And how does being "carburetted to be thrashed out of
>> the
>> tractability power bandwidth" allow a motorcycle with a given
>> amount
>> of horsepower to keep up with traffic when one with the same
>> horsepower but twice the displacement cannot do so?
>
> Ok, I obviously explained this rather badly.
>
> The tractability thing is all about torque, not horses gained from
> high rpm. If you have, say, a 1200cc motor (convert it yourself, but
> I think it's 74 cubes) running at low revs, it may well produce the
> same bhp as a 200cc motor running at higher revs, but the torque
> will
> be very much greater.
>
> In practical terms, this means that the big motor will produce
> _usable_ power throughout its rev range while the small engine
> needs
> to be revved to near its limit to, say, prevent stalling or to
> produce "acceleration" (used in the popular rather than the
> "scientific" sense - I note that there are pedants about.) An
> inexperienced rider is therefore presented with a throttle control
> which turns under his hand with no appreciable effect on the road
> until suddenly, the usable power cuts it like throwing a switch.
> Contrast that with the smooth and predictable power available from
> the
> bigger, slower-revving engine where the relationship between
> throttle
> position and road speed is (perceptibly) linear.
>
> A 125cc 10 bhp will typically need to be revved to (guessing)
> 10-14000 rpm to produce the same road speed as a 60 horse motor
> ticking away at (again guessing - don't pick a fight over the exact
> figures) 2 or 3 thousand rpm. The low displacement motor needs very
> precise gear-stick dancing to keep it running in its usable power
> range.

Motorcycles don't have gear-sticks. At least not modern ones. They
shift with a pedal, with each pedal movement shifting one gear up or
down.

> If the revs drop as traffic speed drops, power will not be
> available to keep up with the next increase in mean traffic speed
> unless the motor is revved back into its power band and the rider
> controls road speed with the gears. A bigger engine can just be
> tailed off and picked up again on the throttle.
>
> This relationship breaks down as one begins to approach the speed of
> light, of course, which makes it harder to draw graphs in crayons of
> only one colour.
>
> The point I _thought_ I was making was that U.K. legislation has
> decreed that inexperienced riders must use machines which really
> need
> more experience to drive safely on the road than the bigger machines
> that they are banned from using.
>
> Therefore, legislation is not the arbiter of truth.

You still haven't explained how a horsepower limit causes the problems
you describe.

Here are two 35 hp motorcycles that are popular in the US.

http://www.buell.com/en_us/bikes/blast/
http://www.kawasaki.com/PRODUCTS/detail.aspx?id=263&content=details


One has 500 cc, producing 34 horsepower at 6400 RPM and 32 foot-pounds
of torque at 3200 RPM.

The other has 250 cc, producing 36 horsepower at 11,000 RPM and 16
foot-pounds of torque at 9500 RPM.

A 1200 cc VW also produces 36 horsepower at even lower RPM and with
even more torque and before you say something ignorant about VW
engines being unsuited to use in motorcycles you might want to google
"Amazonas Motorcycle", which was series produced in Brazil using a VW
engine.

So you see that there is nothing in a _horsepower_ limit that requires
that an engine be intractable. A large engine can easily be detuned
to produce low power and in the process it gains tractability.

The concerns that you express would be the result of a _displacement_
limit, not a horsepower limit.

>>
>>> Is, or is not, the practice of fitting dado blades to table saws
>>> actually dangerous?
>>>
>>> Opinions, please, gentlefolk.
>>
>> Not gonna touch that one.
>
> Come on, you like to prod me on the side-issues - have the courage
> to
> answer the question :-)

I figured you were trolling and the comments you made above ("pompous
waffle" etc) tend to confirm that. Sorry, Borg, but I'm not going to
alleviate your boredom that way.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

LM

"Lee Michaels"

in reply to saulgoode on 27/07/2008 11:12 AM

21/08/2008 7:26 PM


"Edwin Pawlowski" wrote
>
> Why yes, of course that is exactly what it means. Not only are we more
> refined and dignified, we are more conscientious and skilled at operating
> complex machinery. And our beer is colder too.
>
And barbecue, we got barbecue.


Lr

"Leon"

in reply to saulgoode on 27/07/2008 11:12 AM

22/08/2008 10:23 AM


"Bored Borg" <[email protected]> wrote in message
news:[email protected]...
> So, let's see if I have this straight:
>
> Here in Europe, the law decrees that we're not allowed to fit dado sets to
> table saws because that'd be dangerous.
>
> Does that mean that it's _safe_ in the good ol' USA?


Exactly right! Apparently some people are less prone to accidents or
getting sick. If you live in California you are much more prone to getting
cancer if you cook out doors with charcoal.


You’ve reached the end of replies