I was just reading about Powermatics new table saw, the PM2000. One of
the new features highlighted was a riving knife, a feature that the
predicted would become mandatory in the next ten years. To me it looks
like a splitter only it is attached to the trunnion rather than the
fence. Is there something more to the difference or is the name change
just to differentiate the mounting location?
A riving knife is a common feature on European saws. Its main
attribute is that it rises and falls and tilts with the blade, allowing
you pretty much use it for almost all cuts. Its more complicated
mechanically and more expensive to manufacture. I looked into buying
parts from Europe to add a riving knife to my table saw. I finally gave
up. One of the barriers to making such a device standard in the USA is
working through the safety and legal barriers.
Bob
BillyBob wrote:
> "Lobby Dosser" <[email protected]> wrote in message
> news:9yGVe.3113$YI6.192@trnddc05...
>
> > Take a look at the BTXX mount. Two bolts and some shims to center the
> > knife on the blade. The distance between the knife and blade is fixed and
> > it moves up and down and tilts With the blade. No complexity.
>
> With simpleness comes compromise in function. I described a riving knife
> that does more. Its not so complex if its built from the factory to begin
> with. But retrofitting requires disassembley of many things and replacement
> of some major cast parts.
>
> Bob
no compromise with that mechanism. arbor travel is linear in that saw,
rather than pivot. it works fine.
the problems with it are from the castings being aluminum, rather than
from configuration.
"BillyBob" <[email protected]> wrote in message
news:[email protected]...
>
> I lived there as well and would gladly use a parts hunting trip as an
> excuse
> to get back there. I might not get the parts, but it would be fun anyway.
>
> Bob
>
>
Yeah, fortunately, my wife has family there so we try to get back once a
year if possible. I lived in Dublin just shy of City Centre and loved
every minute of it. Great fun and close to just about anywhere in Europe.
I'd move back if I thought I could afford it but unfortunately, it's gotten
ridiculously expensive. I do miss the "true" pint of Guinness....this crap
they serve in the states just doesn't do justice to it.
Cheers,
cc
BillyBob wrote:
>
> "Lobby Dosser" <[email protected]> wrote in message
> news:73tVe.3700$XO6.3576@trnddc03...
>
>> It's actually pretty simple and inexpensive. I've got an Old (~8yrs)
>> Ryobi BT3000 that came with one and All the Ryobi BTXX saws have them.
>
> The BT3000 implementation is an American bastardized implementation. Its
> got those dreadful anit-kickback pawls and its taller than the blade.
> These facets prevent using leaving the knife in place for a number of
> cuts,
> including tenon cuts. Admittedly the BT3000 is ahead of its time in the
> US marketplace in this particular area.
>
> Bob
An inventor and user of the BT came out with a much better version. The
shark gaurd, the reason IT is taller, is due to it being the place to mount
the blade gaurd to. I've thought about getting his and modifying the
original as a more normal riving knife.
On Tue, 13 Sep 2005 05:01:55 GMT, Lobby Dosser
<[email protected]> wrote:
>[email protected] wrote:
>
>> A riving knife is a common feature on European saws. Its main
>> attribute is that it rises and falls and tilts with the blade, allowing
>> you pretty much use it for almost all cuts. Its more complicated
>> mechanically and more expensive to manufacture. I looked into buying
>> parts from Europe to add a riving knife to my table saw. I finally gave
>> up. One of the barriers to making such a device standard in the USA is
>> working through the safety and legal barriers.
>>
>> Bob
>>
>>
>
>It's actually pretty simple and inexpensive. I've got an Old (~8yrs) Ryobi
>BT3000 that came with one and All the Ryobi BTXX saws have them.
As do shopsmiths (Models 510 and 520 since the mid 1980s, not the old
no longer made model 500s).
Dave Hall
Dave Hall
"The power of accurate observation is commonly called cynicism by those who
have not got it." -- G.B. Shaw
"Lobby Dosser" <[email protected]> wrote in message
news:73tVe.3700$XO6.3576@trnddc03...
> It's actually pretty simple and inexpensive. I've got an Old (~8yrs) Ryobi
> BT3000 that came with one and All the Ryobi BTXX saws have them.
The BT3000 implementation is an American bastardized implementation. Its
got those dreadful anit-kickback pawls and its taller than the blade. These
facets prevent using leaving the knife in place for a number of cuts,
including tenon cuts. Admittedly the BT3000 is ahead of its time in the US
marketplace in this particular area.
Bob
[email protected] wrote:
> A riving knife is a common feature on European saws. Its main
> attribute is that it rises and falls and tilts with the blade, allowing
> you pretty much use it for almost all cuts. Its more complicated
> mechanically and more expensive to manufacture. I looked into buying
> parts from Europe to add a riving knife to my table saw. I finally gave
> up. One of the barriers to making such a device standard in the USA is
> working through the safety and legal barriers.
>
> Bob
>
>
It's actually pretty simple and inexpensive. I've got an Old (~8yrs) Ryobi
BT3000 that came with one and All the Ryobi BTXX saws have them.
"BillyBob" <[email protected]> wrote:
>
> "James "Cubby" Culbertson" <[email protected]> wrote in message
> news:[email protected]...
>
>> Does anyone know of a source for riving knives that one could adapt
>> for
> the
>> US made (or sold!) saws? I too am most interested in installing
>> such a beast but don't have the patience (read: time) to try to
>> figure one out
> at
>> the moment.
>
> I'll be so bold as to say there are none. Adding one requires
> machining or replacement of existing parts. Its not a simple bolt-on
> affair. A well designed riving knife has mechanical linkages that
> keep its position and distance from the blade constant, as the blade
> is raised and lowered. This is a non-linear linkage, since the back
> edge of the blade-table intersection shifts forward as the blade is
> lowered. Jet makes commercial parts to support a Riving knife on some
> of their saws. I actually got the manual and parts numbers through a
> contact in Ireland. But actually buying and getting the parts is an
> impossible task. The european and american operations have no
> relationship with each other. I gave up.
>
> Bob
Take a look at the BTXX mount. Two bolts and some shims to center the
knife on the blade. The distance between the knife and blade is fixed and
it moves up and down and tilts With the blade. No complexity.
Here's a link to the manual:
<http://www.bt3central.com/articles/layoutpage.asp?ArticleId=65>
>
>
>
"James "Cubby" Culbertson" <[email protected]> wrote in message
news:[email protected]...
> Hmmm, I lived in Ireland for 3.5 years and my wife is from there. Might
> have to look into this a bit. It actually might be easier for me to just
> make my own in the long run. I've got a Griz. cabinet saw so not sure if
> the Jet stuff is interchangeable.
I lived there as well and would gladly use a parts hunting trip as an excuse
to get back there. I might not get the parts, but it would be fun anyway.
Bob
Dave Hall <[email protected]> wrote:
> If a tool as lowly
> in some people's eyes as a Shopsmith can have a functioning riving
> kinife, then why can't a $2,000 Powermatic? (Said with a wink since a
> new Shopsmith costs more than $2,000).
>
Or even lower, the BTXX. I'm a real sucker for gadgets and the BT sliding
table reeled me in.
Dave Hall <[email protected]> wrote in
news:[email protected]:
> On Tue, 13 Sep 2005 05:01:55 GMT, Lobby Dosser
> <[email protected]> wrote:
>
>>[email protected] wrote:
>>
>>> A riving knife is a common feature on European saws. Its main
>>> attribute is that it rises and falls and tilts with the blade,
>>> allowing you pretty much use it for almost all cuts. Its more
>>> complicated mechanically and more expensive to manufacture. I
>>> looked into buying parts from Europe to add a riving knife to my
>>> table saw. I finally gave up. One of the barriers to making such a
>>> device standard in the USA is working through the safety and legal
>>> barriers.
>>>
>>> Bob
>>
>>It's actually pretty simple and inexpensive. I've got an Old (~8yrs)
>>Ryobi BT3000 that came with one and All the Ryobi BTXX saws have them.
>
> As do shopsmiths (Models 510 and 520 since the mid 1980s, not the old
> no longer made model 500s).
>
> Dave Hall
I'm not certain how this applies, regarding the Shopsmith. The Shopsmith
uses a tilting _table_, rather than an arbor, and otherwise has a blade
guard just as clunky as any US-delivered Delta or Powermatic. The tilting
table arrangement makes for some high pucker factor mitered cross cuts, and
effectively precludes its use on anything longer than about 12".
Patriarch,
embarrassed owner of a Model 520, who learned better...
Dave Hall <[email protected]> wrote in
news:[email protected]:
> On Tue, 13 Sep 2005 11:00:22 -0500, Patriarch
> <[email protected]> wrote:
>
>>Dave Hall <[email protected]> wrote in
>>news:[email protected]:
>
>>>>
>>>>It's actually pretty simple and inexpensive. I've got an Old (~8yrs)
>>>>Ryobi BT3000 that came with one and All the Ryobi BTXX saws have
>>>>them.
>>>
>>> As do shopsmiths (Models 510 and 520 since the mid 1980s, not the
>>> old no longer made model 500s).
>>>
>>> Dave Hall
>>
>>I'm not certain how this applies, regarding the Shopsmith. The
>>Shopsmith uses a tilting _table_, rather than an arbor, and otherwise
>>has a blade guard just as clunky as any US-delivered Delta or
>>Powermatic. The tilting table arrangement makes for some high pucker
>>factor mitered cross cuts, and effectively precludes its use on
>>anything longer than about 12".
>>
>>Patriarch,
>>embarrassed owner of a Model 520, who learned better...
>
> While I understand that you do not like your Shopsmith there are lots
> of people who have made very nice furniture and other projects with
> them. I can assure you that they often have to make mitered crosscuts
> on boards longer than 12". My crosscut sled is wider than 12" and it
> works quite well on mitered crosscuts. In fact I would not be
> concerned in the least in making a 45 degree mitered crosscut on
> boards 4 or 5 foot long. After that the physics do limit you since the
> other end of the board might drag on the floor or hit the ceiling, so
> I use either my compound miter saw or my RAS. Contrary to popular
> belief, you can also make mitered rip cuts on long boards quite well
> on a Shopsmith. In any case, the issue was riving knives - and
> Shopsmiths have them. They stay the same distance from the blade no
> matter the depth, they are in place for all miter cuts and they are
> extremely easy to take off and reinstall as needed. If a tool as lowly
> in some people's eyes as a Shopsmith can have a functioning riving
> kinife, then why can't a $2,000 Powermatic? (Said with a wink since a
> new Shopsmith costs more than $2,000).
> Dave Hall
>
> "The power of accurate observation is commonly called cynicism by
> those who have not got it." -- G.B. Shaw
Not to drift TOO far off topic, but...
Maybe it's a user error. Tilt the table to 45 degrees, down on the
right. Can't go left, because the motor unit's there. At some, fairly
quick length limitation, you run into the tubes and/or right table
support. Move everything to the end, like one would on a bowl lathe?
On that undersized table? Clamping everything to a sled, so it doesn't
slide off? Get me a freakin' hand saw & a good plane!
Again, a riving knife on a tilting TABLE is a piece of cake. It's the
tilting TABLE that is an obsolete, questionable design.
What really pissed me off about the Shopsmith really was that I got
taken in by the hype, and bought at a home show. I paid way more than
Unisaw money, and should have just walked away. The 'only works on
Shopsmith' accessories were a rude surprise, too. Every needed add-on
piece required another mail order, with a 10 day delay, and an expensive
charge.
Yes, folks can really do nice work on a Shopsmith. I did, too,
actually. But it was WAY more work than it needed to be, with a lot
more scrap. The Shopsmith sits in storage, replaced by real tools. One
of my sons wants it, when he gets out of his apartment space limits.
There. Sorry. That feels better. I'm going to the shop now.
Patriarch
"Lobby Dosser" <[email protected]> wrote in message
news:9yGVe.3113$YI6.192@trnddc05...
> Take a look at the BTXX mount. Two bolts and some shims to center the
> knife on the blade. The distance between the knife and blade is fixed and
> it moves up and down and tilts With the blade. No complexity.
With simpleness comes compromise in function. I described a riving knife
that does more. Its not so complex if its built from the factory to begin
with. But retrofitting requires disassembley of many things and replacement
of some major cast parts.
Bob
"Ken" <[email protected]> wrote in message
news:[email protected]...
>I was just reading about Powermatics new table saw, the PM2000. One of
> the new features highlighted was a riving knife, a feature that the
> predicted would become mandatory in the next ten years. To me it looks
> like a splitter only it is attached to the trunnion rather than the
> fence. Is there something more to the difference or is the name change
> just to differentiate the mounting location?
>
Does anyone know of a source for riving knives that one could adapt for the
US made (or sold!) saws? I too am most interested in installing such a
beast but don't have the patience (read: time) to try to figure one out at
the moment.
Cheers,
cc
On 13/09/2005 11:38 AM, James "Cubby" Culbertson wrote:
> Does anyone know of a source for riving knives that one could adapt for the
> US made (or sold!) saws? I too am most interested in installing such a
> beast but don't have the patience (read: time) to try to figure one out at
> the moment.
You might also be interested in microjig splitters:
http://www.microjig.com/
"James "Cubby" Culbertson" <[email protected]> wrote in message
news:[email protected]...
> Does anyone know of a source for riving knives that one could adapt for
the
> US made (or sold!) saws? I too am most interested in installing such a
> beast but don't have the patience (read: time) to try to figure one out
at
> the moment.
I'll be so bold as to say there are none. Adding one requires machining or
replacement of existing parts. Its not a simple bolt-on affair. A well
designed riving knife has mechanical linkages that keep its position and
distance from the blade constant, as the blade is raised and lowered. This
is a non-linear linkage, since the back edge of the blade-table intersection
shifts forward as the blade is lowered. Jet makes commercial parts to
support a Riving knife on some of their saws. I actually got the manual and
parts numbers through a contact in Ireland. But actually buying and getting
the parts is an impossible task. The european and american operations have
no relationship with each other. I gave up.
Bob
On Tue, 13 Sep 2005 11:00:22 -0500, Patriarch
<[email protected]> wrote:
>Dave Hall <[email protected]> wrote in
>news:[email protected]:
>>>
>>>It's actually pretty simple and inexpensive. I've got an Old (~8yrs)
>>>Ryobi BT3000 that came with one and All the Ryobi BTXX saws have them.
>>
>> As do shopsmiths (Models 510 and 520 since the mid 1980s, not the old
>> no longer made model 500s).
>>
>> Dave Hall
>
>I'm not certain how this applies, regarding the Shopsmith. The Shopsmith
>uses a tilting _table_, rather than an arbor, and otherwise has a blade
>guard just as clunky as any US-delivered Delta or Powermatic. The tilting
>table arrangement makes for some high pucker factor mitered cross cuts, and
>effectively precludes its use on anything longer than about 12".
>
>Patriarch,
>embarrassed owner of a Model 520, who learned better...
While I understand that you do not like your Shopsmith there are lots
of people who have made very nice furniture and other projects with
them. I can assure you that they often have to make mitered crosscuts
on boards longer than 12". My crosscut sled is wider than 12" and it
works quite well on mitered crosscuts. In fact I would not be
concerned in the least in making a 45 degree mitered crosscut on
boards 4 or 5 foot long. After that the physics do limit you since the
other end of the board might drag on the floor or hit the ceiling, so
I use either my compound miter saw or my RAS. Contrary to popular
belief, you can also make mitered rip cuts on long boards quite well
on a Shopsmith. In any case, the issue was riving knives - and
Shopsmiths have them. They stay the same distance from the blade no
matter the depth, they are in place for all miter cuts and they are
extremely easy to take off and reinstall as needed. If a tool as lowly
in some people's eyes as a Shopsmith can have a functioning riving
kinife, then why can't a $2,000 Powermatic? (Said with a wink since a
new Shopsmith costs more than $2,000).
Dave Hall
"The power of accurate observation is commonly called cynicism by those who
have not got it." -- G.B. Shaw
"Doug Payne" <[email protected]> wrote in message
news:[email protected]...
> You might also be interested in microjig splitters:
>
> http://www.microjig.com/
I've got one but haven't yet installed it. I figured I'd better get an
overhead guard build first but am looking forward to using it.
Cheers,
cc
On Wed, 14 Sep 2005 10:22:58 -0500, Patriarch
<[email protected]> wrote:
>>
>> While I understand that you do not like your Shopsmith there are lots
>> of people who have made very nice furniture and other projects with
>> them. I can assure you that they often have to make mitered crosscuts
>> on boards longer than 12". My crosscut sled is wider than 12" and it
>> works quite well on mitered crosscuts. In fact I would not be
>> concerned in the least in making a 45 degree mitered crosscut on
>> boards 4 or 5 foot long. After that the physics do limit you since the
>> other end of the board might drag on the floor or hit the ceiling, so
>> I use either my compound miter saw or my RAS. Contrary to popular
>> belief, you can also make mitered rip cuts on long boards quite well
>> on a Shopsmith. In any case, the issue was riving knives - and
>> Shopsmiths have them. They stay the same distance from the blade no
>> matter the depth, they are in place for all miter cuts and they are
>> extremely easy to take off and reinstall as needed. If a tool as lowly
>> in some people's eyes as a Shopsmith can have a functioning riving
>> kinife, then why can't a $2,000 Powermatic? (Said with a wink since a
>> new Shopsmith costs more than $2,000).
>> Dave Hall
>>
>> "The power of accurate observation is commonly called cynicism by
>> those who have not got it." -- G.B. Shaw
>
>Not to drift TOO far off topic, but...
>
>Maybe it's a user error. Tilt the table to 45 degrees, down on the
>right. Can't go left, because the motor unit's there. At some, fairly
>quick length limitation, you run into the tubes and/or right table
>support. Move everything to the end, like one would on a bowl lathe?
>On that undersized table? Clamping everything to a sled, so it doesn't
>slide off? Get me a freakin' hand saw & a good plane!
Guess I didn't say it didn't take a moment or two to set up, a little
planning and some fine grit sandpaper on the fence of your sled to
keep things from sliding. BTW you can go left because you can extend
the quill to get the table far enough away from the headstock to clear
it. I don't know if you can get the full 45 degrees though.
>Again, a riving knife on a tilting TABLE is a piece of cake. It's the
>tilting TABLE that is an obsolete, questionable design.
No argument that if you were buying a saw that a tilting table would
be a poor design. If you bought a Shopsmith, however, you were not
buying a saw, you were buying a multi-purpose tool. As with any such
beast some design compromises are requied for each purpose in order to
allow for the other purposes. There is just no way to produce a
machine that does those specific 5 functions without a tilting table.
I agree that if a person has the room for all stand alone tools and
the desire to dedicate that space to woodworking tools then a
Shopsmith is clearly not their best choice.
>What really pissed me off about the Shopsmith really was that I got
>taken in by the hype, and bought at a home show. I paid way more than
>Unisaw money, and should have just walked away. The 'only works on
>Shopsmith' accessories were a rude surprise, too. Every needed add-on
>piece required another mail order, with a 10 day delay, and an expensive
>charge.
I can understand that! Too many things need Shopsmith specific stuff,
and they do seem quite proud of their stuff given the price. Actually
that would be expected for a niche product with a small market and
small volumes.
>Yes, folks can really do nice work on a Shopsmith. I did, too,
>actually. But it was WAY more work than it needed to be, with a lot
>more scrap. The Shopsmith sits in storage, replaced by real tools. One
>of my sons wants it, when he gets out of his apartment space limits.
>
>There. Sorry. That feels better. I'm going to the shop now.
>
>Patriarch
;-)
Dave Hall
"The power of accurate observation is commonly called cynicism by those who
have not got it." -- G.B. Shaw
"BillyBob" <[email protected]> wrote in message
news:[email protected]...
> I'll be so bold as to say there are none. Adding one requires machining or
> replacement of existing parts. Its not a simple bolt-on affair. A well
> designed riving knife has mechanical linkages that keep its position and
> distance from the blade constant, as the blade is raised and lowered.
> This
> is a non-linear linkage, since the back edge of the blade-table
> intersection
> shifts forward as the blade is lowered. Jet makes commercial parts to
> support a Riving knife on some of their saws. I actually got the manual
> and
> parts numbers through a contact in Ireland. But actually buying and
> getting
> the parts is an impossible task. The european and american operations have
> no relationship with each other. I gave up.
>
> Bob
Hmmm, I lived in Ireland for 3.5 years and my wife is from there. Might
have to look into this a bit. It actually might be easier for me to just
make my own in the long run. I've got a Griz. cabinet saw so not sure if
the Jet stuff is interchangeable.
Cheers,
cc