Well, today I finally broke down and finished a cross-cut sled for
the tablesaw. This was motivated by needing more square cuts than I could
get with the miter gauge; no matter how hard I tried to adjust the gauge.
This problem was really evident when cutting material for the Leigh jig.
Now I'm wondering why I waited so long (OK, one reason was because
I didn't want to take the time). The test cuts have come out to less than
0.0015" over 5", which equates to less than 0.003 out of square over 12".
Much better than anything I could have gotten with the miter gauge.
I had built one of these several years ago using oak and plywood --
the mistake I made with the original was that I made it too large -- it was
unwieldy and a pain to try to put on the saw and use. In addition, the
plywood I used from Payless Cashway was not stable enough to remain flat.
The new one is smaller, easily placed on the saw, and made using an MDF
base for stability.
The only thing I am uncomfortable with is that I see no way to
emply a splitter with a sliding table; I suspect this won't be a problem,
but I'm not used to using the saw without one for through cuts.
"How" and "What" are you using to make these measurements
on wood and of course "why" ???
Mark & Juanita wrote:
> Well, today I finally broke down and finished a cross-cut sled for
> the tablesaw. This was motivated by needing more square cuts than I could
> get with the miter gauge; no matter how hard I tried to adjust the gauge.
> This problem was really evident when cutting material for the Leigh jig.
>
> Now I'm wondering why I waited so long (OK, one reason was because
> I didn't want to take the time). The test cuts have come out to less than
> 0.0015" over 5", which equates to less than 0.003 out of square over 12".
> Much better than anything I could have gotten with the miter gauge.
>
> I had built one of these several years ago using oak and plywood --
> the mistake I made with the original was that I made it too large -- it was
> unwieldy and a pain to try to put on the saw and use. In addition, the
> plywood I used from Payless Cashway was not stable enough to remain flat.
> The new one is smaller, easily placed on the saw, and made using an MDF
> base for stability.
>
> The only thing I am uncomfortable with is that I see no way to
> emply a splitter with a sliding table; I suspect this won't be a problem,
> but I'm not used to using the saw without one for through cuts.
"Mark & Juanita" wrote in message
> The only thing I am uncomfortable with is that I see no way to
> emply a splitter with a sliding table; I suspect this won't be a problem,
> but I'm not used to using the saw without one for through cuts.
I'd venture that most of my crosscuts on a sled are less than the width of
the blade and wouldn't even engage a splitter. There are exceptions of
course, like when crosscutting panels, but generally those are done on
stable materials that are not likely to close up on the blade, and anything
laying on the table of the sled is basically stationary from the surface to
surface friction since it is the sled that's moving, not the material.
IME with a sled, much of the hazard to precision can to come from pulling
the cut piece back though the blade after the cut is made. On critical
pieces, I don't even attempt to pull the sled back to the starting position
until the blade stops on each individual cut ... too many times just the
slight kiss of the blade on the drawback (either from the inevitable slop in
the runners, or slight movement of the part) is enough to lose the precision
of the sled.
...and, if you're like me, don't forget to put the splitter back on when you
take the sled off.
--
www.e-woodshop.net
Last update: 5/15/04
On Sat, 22 May 2004 14:19:50 GMT, "K. B." <[email protected]>
wrote:
>Being a newbie, with a sled on the next to-do list, was wondering if you
>used both miter slots or if you used just one?
Depends on the size of the sled.
Lookie here: <http://www.bburke.com/wood/sleds.htm>
Barry
On Sat, 22 May 2004 09:54:11 -0500, "Swingman" <[email protected]> wrote:
>
>"K. B." <[email protected]> wrote in message
>news:[email protected]...
>> Being a newbie, with a sled on the next to-do list, was wondering if you
>> used both miter slots or if you used just one? I am wondering how to get
>> two rails aligned with the sled's base, with the slots, so it wont stick
>> when you push the sled through the board?
>
... snip
>TIP: use your fence as a guide for the right edge of the sled base during
>this above operation.
>
That's how I did it
>Now carefully remove the entire assembly without upsetting the position of
>the runners, and permanently mount them to the bottom of the base with the
>remaining screws.
I made this easier by putting more than two screws in the runners before
removing from the saw (I used 4 along the length of the sled on the table).
>
>The next trick is to get the back fence of the sled perpendicular to the saw
>blade once the runners are in place.
>
>The philosophy behind this is to fasten one _end_ of the fence with a screw
>to the base, and the opposite end of the fence to the base through a
>slightly oversize screw hole, just big enough to give you a bit of wiggle
>room for adjustment on ONE end.
>
I took a slightly different approach. I did attach the one end with a
single screw. I then made the initial cut in the sled, cutting to about 1"
from where the back fence would be attached. Using a machinist's square, I
then moved the back fence to as near square as detectable with fingernail
and feeler gauge. I then clamped down the back fence and used a single
screw to hold the fence down. I made a test cut and measured the deviation
with the machinist's square and feeler gauge. The first cut was off a bit,
so I used a rubber mallet to "adjust" the fence in the correct direction.
After a couple of tries, I got the measurements I alluded to in my original
post. After getting that precision, I then screwed down the back fence
with multiple screws to keep it in place.
... snip
fOn Sat, 22 May 2004 23:40:16 GMT, "Agki Strodon"
<[email protected]> wrote:
>
>"Bruce" <[email protected]> wrote in message
>news:[email protected]...
>> In rec.woodworking
>> Richard Cline <[email protected]> wrote:
>>
>> >> Now I'm wondering why I waited so long (OK, one reason was because
>> >> I didn't want to take the time). The test cuts have come out to less
>> >> than
>> >> 0.0015" over 5", which equates to less than 0.003 out of square over
>12".
>> >> Much better than anything I could have gotten with the miter gauge.
>> >
>> >I don't quite understand your logic here. If you put two pieces
>> >together the error is additive. An error of 0.0015" across 5" will
>> >cause a joint to be 0.003" out of square across 5".
>>
>> I think you're misunderstanding what he is saying. If he cut a board 12"
>> wide, the error would be that much larger than it was at 5". And if he
>cut
>> a 24" board, it would be even larger. See?
>
>The error in "squareness" is based upon a defect in the angle of the cut
>relative to the side of the board that is supposed to be perpendicular to
>the cut in order for it to be "square" (as in a right triangle). As I am
>getting this, when we take the side of the board parallel to the rail of the
>table and the one that the blade engages is taken as the reference line from
>which the kerf is supposed to be absolutely perpendicular in order for the
>cut to be "square," then the error on the other side of the board (the one
>on the rail side) is such that the deviation from perpendicularity is only
>0.0015" over a board 5" wide?
>
>
> Side A of board
>____________________________Vertex A
> |
> |
> |
> |
>____________________________| Vertex B
> Side B of board
>
>When sawn on a perfectly aligned machine (one that can exist only in the
>imagination) then Vertex A = Vertex B = 90 degrees iff Side A is parallel to
>Side B (not demonstrated by the original poster) and the right side of the
>board is "square".
>
>But if the alignment is not "perfect", then the angles of Vertices A and B
>would not be 90 degrees and the end would not be square. So, is the
>gentleman saying that the deviation from perfect square across a 5" distance
>between *lines* A and B is 0.0015"? If that is the case, then we have:
>
>Side A of Board
>____________________________ Vertex A
> /|
> / |
> / |
> / |
>_________________________ /__| *Vertex B
>Side B of Board C D
>
>Highly exaggerated, of course but *Vertex B (also Point D) would be the
>perfectly aligned position. However, due to the error, C becomes the Vertex
>B and the distance from C to D is 0.0015". Is that what you understand this
>to be?
>
yep, what both Bruce and AgkiS said. That is exactly what I was
describing.
As further clarification, My only concern was with side B of the board,
a piece that had been jointed flat only moments before performing these
tests.
... snip
>WOW!!!! I doubt that this degree of error would ever be worried about by
>any woodworker - if that is what the original poster meant by error over 5".
What I meant.
... snip
>So, I ask again, how was this error measured? It seems to me that just
>tightening a tape measure could compress wood by that much at the
>application point... then you've got the error of the tape measure and the
>error of your eye and the error of the changing water content of the board
>and some other errors thrown in. I'd say it's close enough for government
>work ... IN THE OLD SENSE!!!
>
As I responded in another post, I used a machinist square and feeler
gauge. Actually, the error is slightly under 0.0015, but my feeler gauge
set doesn't have anything smaller. I'm certainly hoping this is
sufficiently good such that only slight planing or sanding will be required
for any boxes built using the Leigh jig.
>Oh, yeah. Note that in the second ASCII Art attempt, the misalignment could
>have been rotated the other way but the 2 seconds of arc would be the same
>since the ideal vertex would form the midpoint of the base of an isosceles
>triangle.
BTW, the error was in the other direction, but, as you say, the effect is
the same, I just had to apply the mallet in the opposite direction :-)
>
>Agkistrodon
>
In rec.woodworking
Richard Cline <[email protected]> wrote:
>> Now I'm wondering why I waited so long (OK, one reason was because
>> I didn't want to take the time). The test cuts have come out to less
>> than
>> 0.0015" over 5", which equates to less than 0.003 out of square over 12".
>> Much better than anything I could have gotten with the miter gauge.
>
>I don't quite understand your logic here. If you put two pieces
>together the error is additive. An error of 0.0015" across 5" will
>cause a joint to be 0.003" out of square across 5".
I think you're misunderstanding what he is saying. If he cut a board 12"
wide, the error would be that much larger than it was at 5". And if he cut
a 24" board, it would be even larger. See?
In rec.woodworking
"Gregory Jensen" <gjensen [email protected]> wrote:
>I used Eds P's advice and got mine down to 0 .00000015 outta square in 5
>inches
3.8 nanometers. Not bad :) That is less than the width of 2 hydrogen
atoms. I'm impressed.
On Sun, 23 May 2004 18:05:31 GMT, "Edwin Pawlowski" <[email protected]>
wrote:
>
>"Bruce" <[email protected]> wrote in message
>>
>> 3.8 nanometers. Not bad :) That is less than the width of 2 hydrogen
>> atoms. I'm impressed.
>>
>
>Is there a way to get those hydrogen atoms out of the way for a closer fit?
>Ed
>
Sure, but you need a shop-vac. It's simple physics, right? After all,
nature abhors a vacuum.
tt
On Fri, 28 May 2004 19:53:09 -0700, [email protected] wrote:
>>>I made up a little PDF about my table saw sled. it's posted to ABPW.
I'm going to put this up soon.
My home DSL line is a test / development line, usually unrestricted
at 6-8 megs. Unfortunately, tests of the latest stuff aren't going so
well, so I'm stuck at 21.6 via dial up. 8^(
As soon as the DSL line is dependable, I'll add your ideas.
Thanks again!
Barry
On Sat, 22 May 2004 05:00:40 GMT, Mark & Juanita
<[email protected]> wrote:
> The only thing I am uncomfortable with is that I see no way to
>emply a splitter with a sliding table; I suspect this won't be a problem,
>but I'm not used to using the saw without one for through cuts.
You really don't need a splitter for cross cuts.
Barry
On Sun, 23 May 2004 10:28:31 GMT, B a r r y
<[email protected]> wrote:
>On Sat, 22 May 2004 18:50:40 -0700, [email protected] wrote:
>
>
>>I could send you some pics of mine. got a couple of good features
>>going there....
>
>Thanks!
>
>Send 'em to nospam @ snet dot net.
>
>Barry
Barry-
I made up a little PDF about my table saw sled. it's posted to ABPW.
you're free to use it as is on your website, or if you would prefer
I'll send you individual pictures.
bridger
On Tue, 25 May 2004 14:45:04 GMT, Pat Barber
<[email protected]> wrote:
>I grant you that careful measurements are required for
>any woodworking but when I hear folks talking about
>somthing that's .0005 out of square, that's getting a
>little silly.
well, yeah, of course, but depending.....
>
>I own a LOT of measuring devices and I believe I only
>have one ruler that even shows 1/32" marks, which I can
>barely see, little less make a correct mark to.
I do some metalworking too, so I have tooling to measure WAAAY tighter
than is needed for woodworking. I do my designwork on the computer,
and sometimes I can't avoid having things come out in 64ths, as much
of a pain as that is. I do avoid it where possible.
>
>I do have a Incra ruler my wife bought me several years
>ago that has 1/64" and I can say without a shadow of
>doubt, I can NOT measure anything using that ruler.
I've never used incra stuff. it seems to me to be well made and
cleverly designed. My uneasiness with it is around the closed system
thing- their stuff seems like it's designed to have you "need" another
gizmo from their high priced line to do pretty much any next process.
>
>I do all the normal joinery including a few dovetails
>and as a general rule, most of the joints are tight and
>quite fine.
>
>I have seen these silly "measurement" things for several
>years here on the rec and I think it really must make
>people crazy cause they can't measure and cut a board at
>some of these "extreme" tolerances.
But there is one very notable exception to the "32ths is all we need
for woodworking" thing: toolmaking. This should be obvious to you,
Pat. Shopmade tooling should be as accurate as you can make it,
especially something as much used as a crosscut sled. It's not
unreasonable to hold tooling to an order of mgnitude better tolerances
than cabinets or furniture that are the actual product of the shop.
>
>I go to GREAT lengths to "not measure" if at all possible.
but you do want your crosscuts to come out nice and square, right? And
without having to worry about them....
>
>I use story sticks and templates if at all possible.
>
>
>
>Mark & Juanita wrote:
>
>> On Mon, 24 May 2004 15:46:04 GMT, Pat Barber <[email protected]>
>> wrote:
>>
>>
>>>"How" and "What" are you using to make these measurements
>>>on wood and of course "why" ???
>>>
>>
>>
>> How: Machinist's square and feeler gauge
>>
>> Why: Take four pieces that are out of square by 1/32" (or even 1/64" --
>> normal high-precision wood measurements), assemble into a frame. How
>> well-crafted will that frame appear? Just because it doesn't make sense to
>> measure some things to better than 1/32 or 1/64 (or even 1/16) -- there are
>> other times when getting something cut square (or mitered at 45 degrees) to
>> high precision is essential. Another example, take 4 pieces of wood and
>> dovetail all ends to assemble into a box. If all sides of the box are out
>> of square by 1/32, how well will those dovetails fit?
>>
>>
>>
>>>Mark & Juanita wrote:
>>>
>>>
>>>> Well, today I finally broke down and finished a cross-cut sled for
>>>>the tablesaw. This was motivated by needing more square cuts than I could
>>>>get with the miter gauge; no matter how hard I tried to adjust the gauge.
>>>>This problem was really evident when cutting material for the Leigh jig.
>>>>
>>>> Now I'm wondering why I waited so long (OK, one reason was because
>>>>I didn't want to take the time). The test cuts have come out to less than
>>>>0.0015" over 5", which equates to less than 0.003 out of square over 12".
>>>>Much better than anything I could have gotten with the miter gauge.
>>>>
>>>> I had built one of these several years ago using oak and plywood --
>>>>the mistake I made with the original was that I made it too large -- it was
>>>>unwieldy and a pain to try to put on the saw and use. In addition, the
>>>>plywood I used from Payless Cashway was not stable enough to remain flat.
>>>>The new one is smaller, easily placed on the saw, and made using an MDF
>>>>base for stability.
>>>>
>>>> The only thing I am uncomfortable with is that I see no way to
>>>>emply a splitter with a sliding table; I suspect this won't be a problem,
>>>>but I'm not used to using the saw without one for through cuts.
>>
>>
"Bruce" <[email protected]> wrote in message
news:[email protected]...
> In rec.woodworking
> Richard Cline <[email protected]> wrote:
>
> >> Now I'm wondering why I waited so long (OK, one reason was because
> >> I didn't want to take the time). The test cuts have come out to less
> >> than
> >> 0.0015" over 5", which equates to less than 0.003 out of square over
12".
> >> Much better than anything I could have gotten with the miter gauge.
> >
> >I don't quite understand your logic here. If you put two pieces
> >together the error is additive. An error of 0.0015" across 5" will
> >cause a joint to be 0.003" out of square across 5".
>
> I think you're misunderstanding what he is saying. If he cut a board 12"
> wide, the error would be that much larger than it was at 5". And if he
cut
> a 24" board, it would be even larger. See?
The error in "squareness" is based upon a defect in the angle of the cut
relative to the side of the board that is supposed to be perpendicular to
the cut in order for it to be "square" (as in a right triangle). As I am
getting this, when we take the side of the board parallel to the rail of the
table and the one that the blade engages is taken as the reference line from
which the kerf is supposed to be absolutely perpendicular in order for the
cut to be "square," then the error on the other side of the board (the one
on the rail side) is such that the deviation from perpendicularity is only
0.0015" over a board 5" wide?
Side A of board
____________________________Vertex A
|
|
|
|
____________________________| Vertex B
Side B of board
When sawn on a perfectly aligned machine (one that can exist only in the
imagination) then Vertex A = Vertex B = 90 degrees iff Side A is parallel to
Side B (not demonstrated by the original poster) and the right side of the
board is "square".
But if the alignment is not "perfect", then the angles of Vertices A and B
would not be 90 degrees and the end would not be square. So, is the
gentleman saying that the deviation from perfect square across a 5" distance
between *lines* A and B is 0.0015"? If that is the case, then we have:
Side A of Board
____________________________ Vertex A
/|
/ |
/ |
/ |
_________________________ /__| *Vertex B
Side B of Board C D
Highly exaggerated, of course but *Vertex B (also Point D) would be the
perfectly aligned position. However, due to the error, C becomes the Vertex
B and the distance from C to D is 0.0015". Is that what you understand this
to be?
Since the distance A to D is 5" and the distance C to D is 0.0015", we can
find the angle CAD from:
Tan CAD = 0.0015/5 = 0.0003 and angle CAD = Around 2 seconds of arc!
WOW!!!! I doubt that this degree of error would ever be worried about by
any woodworker - if that is what the original poster meant by error over 5".
Hell, I'd bet a damn good roofing square is off by at least that much.
You've got to be a good distance away from Vertex A before such a small
error would be noticed. Consider D to be 5 miles away from Vertex A. Then
C would be out of place by 0.0015 miles and that comes out to be a
misplacement of only 7.92 feet!
So, I ask again, how was this error measured? It seems to me that just
tightening a tape measure could compress wood by that much at the
application point... then you've got the error of the tape measure and the
error of your eye and the error of the changing water content of the board
and some other errors thrown in. I'd say it's close enough for government
work ... IN THE OLD SENSE!!!
Oh, yeah. Note that in the second ASCII Art attempt, the misalignment could
have been rotated the other way but the 2 seconds of arc would be the same
since the ideal vertex would form the midpoint of the base of an isosceles
triangle.
Agkistrodon
"Bruce" <[email protected]> wrote in message
>
> 3.8 nanometers. Not bad :) That is less than the width of 2 hydrogen
> atoms. I'm impressed.
>
Is there a way to get those hydrogen atoms out of the way for a closer fit?
Ed
"Mark & Juanita" <[email protected]> wrote in message
news:[email protected]...
>
Please see my questions below:
<Deletia>
> The test cuts have come out to less than 0.0015" over > 5", which equates
to less than 0.003 out of square over > 12". Much better than anything I
could have gotten > with the miter gauge.
>
How did you measure the squareness this accurately?
<Deletia>
>
> The only thing I am uncomfortable with is that I see no way to
> emply a splitter with a sliding table; I suspect this won't be a problem,
> but I'm not used to using the saw without one for through cuts.
Why do you need one for this kind of cutting?
Agkistrodon
Can you please repost that PDF. It doesn't seem to be there anymore
Thanks,
In article <[email protected]>,
[email protected] says...
> On Sun, 23 May 2004 10:28:31 GMT, B a r r y
> <[email protected]> wrote:
>
> >On Sat, 22 May 2004 18:50:40 -0700, [email protected] wrote:
> >
> >
> >>I could send you some pics of mine. got a couple of good features
> >>going there....
> >
> >Thanks!
> >
> >Send 'em to nospam @ snet dot net.
> >
> >Barry
>
>
>
> Barry-
> I made up a little PDF about my table saw sled. it's posted to ABPW.
> you're free to use it as is on your website, or if you would prefer
> I'll send you individual pictures.
> bridger
>
In article <[email protected]>,
[email protected] says...
> On Fri, 28 May 2004 02:25:06 -0700, [email protected] wrote:
>
> >On Sun, 23 May 2004 10:28:31 GMT, B a r r y
> ><[email protected]> wrote:
> >
> >>On Sat, 22 May 2004 18:50:40 -0700, [email protected] wrote:
> >>
> >>
> >>>I could send you some pics of mine. got a couple of good features
> >>>going there....
> >>
> >>Thanks!
> >>
> >>Send 'em to nospam @ snet dot net.
> >>
> >>Barry
> >
> >
> >
> >Barry-
> >I made up a little PDF about my table saw sled. it's posted to ABPW.
> >you're free to use it as is on your website, or if you would prefer
> >I'll send you individual pictures.
> > bridger
>
>
> Looks like a very functional setup. I liked the through-holes for the
> clamps.
>
Can you repost those pics? can't seem to find them
thanks,
I grant you that careful measurements are required for
any woodworking but when I hear folks talking about
somthing that's .0005 out of square, that's getting a
little silly.
I own a LOT of measuring devices and I believe I only
have one ruler that even shows 1/32" marks, which I can
barely see, little less make a correct mark to.
I do have a Incra ruler my wife bought me several years
ago that has 1/64" and I can say without a shadow of
doubt, I can NOT measure anything using that ruler.
I do all the normal joinery including a few dovetails
and as a general rule, most of the joints are tight and
quite fine.
I have seen these silly "measurement" things for several
years here on the rec and I think it really must make
people crazy cause they can't measure and cut a board at
some of these "extreme" tolerances.
I go to GREAT lengths to "not measure" if at all possible.
I use story sticks and templates if at all possible.
Mark & Juanita wrote:
> On Mon, 24 May 2004 15:46:04 GMT, Pat Barber <[email protected]>
> wrote:
>
>
>>"How" and "What" are you using to make these measurements
>>on wood and of course "why" ???
>>
>
>
> How: Machinist's square and feeler gauge
>
> Why: Take four pieces that are out of square by 1/32" (or even 1/64" --
> normal high-precision wood measurements), assemble into a frame. How
> well-crafted will that frame appear? Just because it doesn't make sense to
> measure some things to better than 1/32 or 1/64 (or even 1/16) -- there are
> other times when getting something cut square (or mitered at 45 degrees) to
> high precision is essential. Another example, take 4 pieces of wood and
> dovetail all ends to assemble into a box. If all sides of the box are out
> of square by 1/32, how well will those dovetails fit?
>
>
>
>>Mark & Juanita wrote:
>>
>>
>>> Well, today I finally broke down and finished a cross-cut sled for
>>>the tablesaw. This was motivated by needing more square cuts than I could
>>>get with the miter gauge; no matter how hard I tried to adjust the gauge.
>>>This problem was really evident when cutting material for the Leigh jig.
>>>
>>> Now I'm wondering why I waited so long (OK, one reason was because
>>>I didn't want to take the time). The test cuts have come out to less than
>>>0.0015" over 5", which equates to less than 0.003 out of square over 12".
>>>Much better than anything I could have gotten with the miter gauge.
>>>
>>> I had built one of these several years ago using oak and plywood --
>>>the mistake I made with the original was that I made it too large -- it was
>>>unwieldy and a pain to try to put on the saw and use. In addition, the
>>>plywood I used from Payless Cashway was not stable enough to remain flat.
>>>The new one is smaller, easily placed on the saw, and made using an MDF
>>>base for stability.
>>>
>>> The only thing I am uncomfortable with is that I see no way to
>>>emply a splitter with a sliding table; I suspect this won't be a problem,
>>>but I'm not used to using the saw without one for through cuts.
>
>
Pat Barber notes:
>I grant you that careful measurements are required for
>any woodworking but when I hear folks talking about
>somthing that's .0005 out of square, that's getting a
>little silly.
>
>I own a LOT of measuring devices and I believe I only
>have one ruler that even shows 1/32" marks, which I can
>barely see, little less make a correct mark to.
>
And the older you get, the more it becomes "barely see".
> do have a Incra ruler my wife bought me several years
>ago that has 1/64" and I can say without a shadow of
>doubt, I can NOT measure anything using that ruler.
Ayup.
>
>I have seen these silly "measurement" things for several
>years here on the rec and I think it really must make
>people crazy cause they can't measure and cut a board at
>some of these "extreme" tolerances.
>
>I go to GREAT lengths to "not measure" if at all possible.
>
>I use story sticks and templates if at all possible.
Just talked to a major woodworking tool manufacturer, hand tool division, and
we spent time discussing how measurements were taken and checked in ye olden
days. Mostly, they weren't. Story sticks did the job, as they'll do it today.
Simple, quick, repeatable almost unto infinity, and CHEAP!
Charlie Self
"Bore, n.: A person who talks when you wish him to listen." Ambrose Bierce, The
Devil's Dictionary
"Richard Cline" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> "Agki Strodon" <[email protected]> wrote:
>
>
> >
> > Side A of Board
> > ____________________________ Vertex A
> > /|
> > / |
> > / |
> > / |
> > _________________________ /__| *Vertex B
> > Side B of Board C D
> >
> > Highly exaggerated, of course but *Vertex B (also Point D) would be the
> > perfectly aligned position. However, due to the error, C becomes the
> > Vertex
> > B and the distance from C to D is 0.0015". Is that what you understand
> > this to be?
> >
> > Since the distance A to D is 5" and the distance C to D is 0.0015", we
can
> > find the angle CAD from:
> >
> > Tan CAD = 0.0015/5 = 0.0003 and angle CAD = Around 2 seconds of arc!
> >
>
> OK up to your last number. The tan of 0.0015/5 =0.0003 = 62 arc
> seconds. Still a very small number. It is fairly reasonable to measure
> this . Take a 4" long board and cut it in the middle. Now flip one
> piece over and put the two cut edges together. The angle error is
> doubled. If you push one piece against a straight edge the other piece
> will deviate from the straight edge by 2 X 0.0015/5 X 24" or 0.014".
> This is still a small number but it is within reach to measure that
> amount.
>
> Dick
Yep. I misread the table. I need one of those fancy calculator things.
Agkistrodon
"K. B." <[email protected]> wrote in message
news:[email protected]...
> Being a newbie, with a sled on the next to-do list, was wondering if you
> used both miter slots or if you used just one? I am wondering how to get
> two rails aligned with the sled's base, with the slots, so it wont stick
> when you push the sled through the board?
That is the easy part. You make the rails and put them into the miter slots.
No place the platform of the sled on the saw. put two screw in each and
they will be aligned. Once in place, you can mark the location, remove
them, and glue and screw as you desire.
Ed
[email protected]
http://pages.cthome.net/edhome
On Tue, 25 May 2004 20:17:27 GMT, Pat Barber <[email protected]>
wrote:
>I'll go along with the "tool maker" needing to
>use 1/64" where practical, but that comes into
>play very rarely for most folks.
>
>In the construction of a cross-cut sled, measuring
>isn't really needed as much as being able to produce
>a "square edge", which can be done, with very little
>in the way of measuring....
>
That certainly may be the case, a methodology for adjusting a sled to
square without measuring is certainly possible. The result and final
precision will probably be very close to the same as obtained by using
precise measuring tools and a couple of fine adjustments. The methodology
I used with a few relatively inexpensive measuring tools was one I found to
be relatively fuss-free, requiring only two tuning taps to the back fence
to get the precision I desired.
As Bridger indicated, this effort was expended on a tool that I plan to
make extensive use of in the future. I certainly do not use such
measurements for assembly of furniture; my use of these precise
measurements is reserved for setting up the equipment.
>
>[email protected] wrote:
>
>> But there is one very notable exception to the "32ths is all we need
>> for woodworking" thing: toolmaking.
Being a newbie, with a sled on the next to-do list, was wondering if you
used both miter slots or if you used just one? I am wondering how to get
two rails aligned with the sled's base, with the slots, so it wont stick
when you push the sled through the board?
Thanks,
KB
"Mark & Juanita" <[email protected]> wrote in message
news:[email protected]...
>
> Well, today I finally broke down and finished a cross-cut sled for
> the tablesaw. This was motivated by needing more square cuts than I could
> get with the miter gauge; no matter how hard I tried to adjust the gauge.
> This problem was really evident when cutting material for the Leigh jig.
>
> Now I'm wondering why I waited so long (OK, one reason was because
> I didn't want to take the time). The test cuts have come out to less than
> 0.0015" over 5", which equates to less than 0.003 out of square over 12".
> Much better than anything I could have gotten with the miter gauge.
>
> I had built one of these several years ago using oak and plywood --
> the mistake I made with the original was that I made it too large -- it
was
> unwieldy and a pain to try to put on the saw and use. In addition, the
> plywood I used from Payless Cashway was not stable enough to remain flat.
> The new one is smaller, easily placed on the saw, and made using an MDF
> base for stability.
>
> The only thing I am uncomfortable with is that I see no way to
> emply a splitter with a sliding table; I suspect this won't be a problem,
> but I'm not used to using the saw without one for through cuts.
On Sat, 22 May 2004 19:23:20 -0500, Morris Dovey <[email protected]>
wrote:
>B a r r y wrote:
>
>> Lookie here: <http://www.bburke.com/wood/sleds.htm>
>
>Good page!
Thanks!
I need more sleds, though. I'd like to add a "reader submission"
section for more ideas. Mine almost all look the same, with the same
design.
Barry
On Sat, 22 May 2004 14:29:14 GMT, "Edwin Pawlowski" <[email protected]> wrote:
>
>
>"K. B." <[email protected]> wrote in message
>news:[email protected]...
>> Being a newbie, with a sled on the next to-do list, was wondering if you
>> used both miter slots or if you used just one? I am wondering how to get
>> two rails aligned with the sled's base, with the slots, so it wont stick
>> when you push the sled through the board?
>
>That is the easy part. You make the rails and put them into the miter slots.
>No place the platform of the sled on the saw. put two screw in each and
>they will be aligned. Once in place, you can mark the location, remove
>them, and glue and screw as you desire.
>Ed
Yep, what he said.
>[email protected]
>http://pages.cthome.net/edhome
>
I used Eds P's advice and got mine down to 0 .00000015 outta square in 5
inches ( whew! I though I would have to do some sanding..) My Gawd,,, my
wood expands and contracts more than that from day to night
Serously the proven method for making a crosscut sled is just what Ed
stated... make the thing then screw on the back platform try and try and try
when your happy GLUE IT.. I remember my first one I made it so perfect so I
guled it together,,, then had to knock it apart, lose an inch to re-align
the thing
thanks
PS I use "SLIPIT" lube ( Non silicon) to lube the sliders--- great stuff
..
"Agki Strodon" <[email protected]> wrote in message
news:[email protected]...
>
> "Mark & Juanita" <[email protected]> wrote in message
> news:[email protected]...
> >
>
> Please see my questions below:
>
> <Deletia>
>
> > The test cuts have come out to less than 0.0015" over > 5", which
equates
> to less than 0.003 out of square over > 12". Much better than anything I
> could have gotten > with the miter gauge.
> >
>
> How did you measure the squareness this accurately?
>
> <Deletia>
> >
> > The only thing I am uncomfortable with is that I see no way to
> > emply a splitter with a sliding table; I suspect this won't be a
problem,
> > but I'm not used to using the saw without one for through cuts.
>
> Why do you need one for this kind of cutting?
>
> Agkistrodon
>
>
On Sat, 22 May 2004 12:09:15 GMT, "Agki Strodon"
<[email protected]> wrote:
>
>"Mark & Juanita" <[email protected]> wrote in message
>news:[email protected]...
>>
>
>Please see my questions below:
>
><Deletia>
>
>> The test cuts have come out to less than 0.0015" over > 5", which equates
>to less than 0.003 out of square over > 12". Much better than anything I
>could have gotten > with the miter gauge.
>>
>
>How did you measure the squareness this accurately?
>
Machinist's square and feeler gauge
><Deletia>
>>
>> The only thing I am uncomfortable with is that I see no way to
>> emply a splitter with a sliding table; I suspect this won't be a problem,
>> but I'm not used to using the saw without one for through cuts.
>
>Why do you need one for this kind of cutting?
>
I probably don't, the two potential issues I see are if the piece being
cut tries to close on itself and to provide some additional protection to
keep the off-cut piece from contacting the back of the blade.
>Agkistrodon
>
In article <[email protected]>, Mark &
Juanita <[email protected]> wrote:
> Well, today I finally broke down and finished a cross-cut sled for
> the tablesaw. This was motivated by needing more square cuts than I
> could
> get with the miter gauge; no matter how hard I tried to adjust the gauge.
> This problem was really evident when cutting material for the Leigh jig.
I built a sled 30 years ago and still use the same sled today. I
recently replaced my table saw and was surprised to find that the sled
fit my new saw. The two slots and the blade align perfectly.
> Now I'm wondering why I waited so long (OK, one reason was because
> I didn't want to take the time). The test cuts have come out to less
> than
> 0.0015" over 5", which equates to less than 0.003 out of square over 12".
> Much better than anything I could have gotten with the miter gauge.
I don't quite understand your logic here. If you put two pieces
together the error is additive. An error of 0.0015" across 5" will
cause a joint to be 0.003" out of square across 5".
Dick
In article <[email protected]>,
"Agki Strodon" <[email protected]> wrote:
>
> Side A of Board
> ____________________________ Vertex A
> /|
> / |
> / |
> / |
> _________________________ /__| *Vertex B
> Side B of Board C D
>
> Highly exaggerated, of course but *Vertex B (also Point D) would be the
> perfectly aligned position. However, due to the error, C becomes the
> Vertex
> B and the distance from C to D is 0.0015". Is that what you understand
> this to be?
>
> Since the distance A to D is 5" and the distance C to D is 0.0015", we can
> find the angle CAD from:
>
> Tan CAD = 0.0015/5 = 0.0003 and angle CAD = Around 2 seconds of arc!
>
OK up to your last number. The tan of 0.0015/5 =0.0003 = 62 arc
seconds. Still a very small number. It is fairly reasonable to measure
this . Take a 4" long board and cut it in the middle. Now flip one
piece over and put the two cut edges together. The angle error is
doubled. If you push one piece against a straight edge the other piece
will deviate from the straight edge by 2 X 0.0015/5 X 24" or 0.014".
This is still a small number but it is within reach to measure that
amount.
Dick
On Fri, 28 May 2004 02:25:06 -0700, [email protected] wrote:
>On Sun, 23 May 2004 10:28:31 GMT, B a r r y
><[email protected]> wrote:
>
>>On Sat, 22 May 2004 18:50:40 -0700, [email protected] wrote:
>>
>>
>>>I could send you some pics of mine. got a couple of good features
>>>going there....
>>
>>Thanks!
>>
>>Send 'em to nospam @ snet dot net.
>>
>>Barry
>
>
>
>Barry-
>I made up a little PDF about my table saw sled. it's posted to ABPW.
>you're free to use it as is on your website, or if you would prefer
>I'll send you individual pictures.
> bridger
Looks like a very functional setup. I liked the through-holes for the
clamps.
On Mon, 24 May 2004 15:46:04 GMT, Pat Barber <[email protected]>
wrote:
>"How" and "What" are you using to make these measurements
>on wood and of course "why" ???
>
How: Machinist's square and feeler gauge
Why: Take four pieces that are out of square by 1/32" (or even 1/64" --
normal high-precision wood measurements), assemble into a frame. How
well-crafted will that frame appear? Just because it doesn't make sense to
measure some things to better than 1/32 or 1/64 (or even 1/16) -- there are
other times when getting something cut square (or mitered at 45 degrees) to
high precision is essential. Another example, take 4 pieces of wood and
dovetail all ends to assemble into a box. If all sides of the box are out
of square by 1/32, how well will those dovetails fit?
>Mark & Juanita wrote:
>
>> Well, today I finally broke down and finished a cross-cut sled for
>> the tablesaw. This was motivated by needing more square cuts than I could
>> get with the miter gauge; no matter how hard I tried to adjust the gauge.
>> This problem was really evident when cutting material for the Leigh jig.
>>
>> Now I'm wondering why I waited so long (OK, one reason was because
>> I didn't want to take the time). The test cuts have come out to less than
>> 0.0015" over 5", which equates to less than 0.003 out of square over 12".
>> Much better than anything I could have gotten with the miter gauge.
>>
>> I had built one of these several years ago using oak and plywood --
>> the mistake I made with the original was that I made it too large -- it was
>> unwieldy and a pain to try to put on the saw and use. In addition, the
>> plywood I used from Payless Cashway was not stable enough to remain flat.
>> The new one is smaller, easily placed on the saw, and made using an MDF
>> base for stability.
>>
>> The only thing I am uncomfortable with is that I see no way to
>> emply a splitter with a sliding table; I suspect this won't be a problem,
>> but I'm not used to using the saw without one for through cuts.
On Sat, 22 May 2004 18:50:40 -0700, [email protected] wrote:
>I could send you some pics of mine. got a couple of good features
>going there....
Thanks!
Send 'em to nospam @ snet dot net.
Barry
On Sat, 29 May 2004 02:02:36 GMT, Mark & Juanita
<[email protected]> wrote:
>On Fri, 28 May 2004 02:25:06 -0700, [email protected] wrote:
>
>>On Sun, 23 May 2004 10:28:31 GMT, B a r r y
>><[email protected]> wrote:
>>
>>>On Sat, 22 May 2004 18:50:40 -0700, [email protected] wrote:
>>>
>>>
>>>>I could send you some pics of mine. got a couple of good features
>>>>going there....
>>>
>>>Thanks!
>>>
>>>Send 'em to nospam @ snet dot net.
>>>
>>>Barry
>>
>>
>>
>>Barry-
>>I made up a little PDF about my table saw sled. it's posted to ABPW.
>>you're free to use it as is on your website, or if you would prefer
>>I'll send you individual pictures.
>> bridger
>
>
> Looks like a very functional setup. I liked the through-holes for the
>clamps.
thanks. I don't clamp everything I cut on it, but when you need to you
really need to....
I use that sled for the majority of crosscuts in my shop.
On Sun, 23 May 2004 01:11:44 GMT, B a r r y
<[email protected]> wrote:
>On Sat, 22 May 2004 19:23:20 -0500, Morris Dovey <[email protected]>
>wrote:
>
>>B a r r y wrote:
>>
>>> Lookie here: <http://www.bburke.com/wood/sleds.htm>
>>
>>Good page!
>
>
>Thanks!
>
>I need more sleds, though. I'd like to add a "reader submission"
>section for more ideas. Mine almost all look the same, with the same
>design.
>
>Barry
I could send you some pics of mine. got a couple of good features
going there....
I'll go along with the "tool maker" needing to
use 1/64" where practical, but that comes into
play very rarely for most folks.
In the construction of a cross-cut sled, measuring
isn't really needed as much as being able to produce
a "square edge", which can be done, with very little
in the way of measuring....
[email protected] wrote:
> But there is one very notable exception to the "32ths is all we need
> for woodworking" thing: toolmaking.
In article <[email protected]>,
"Edwin Pawlowski" <[email protected]> wrote:
> That is the easy part. You make the rails and put them into the miter slots.
> No place the platform of the sled on the saw. put two screw in each and
> they will be aligned. Once in place, you can mark the location, remove
> them, and glue and screw as you desire.
Make them a little less thick than the slot is deep, and shim them up
when you do the initial assembly. This gives you a little clearance
between the bottom of the rail and the bottom of the slot for sawdust
and gunk to fall into and not interfere with the motion.
"Roy Smith" wrote in message
> Make them a little less thick than the slot is deep, and shim them up
> when you do the initial assembly. This gives you a little clearance
> between the bottom of the rail and the bottom of the slot for sawdust
> and gunk to fall into and not interfere with the motion.
Good point ... the easiest way to do this, and to get the runners up against
the base, is with two dimes in each miter slot underneath the runners. Dimes
are just the right thickness for this "clearance".
Of course, since this is an "international forum", you may not be able to do
this ... but you will at least have one more reason to hate us here in the
US.
--
www.e-woodshop.net
Last update: 5/15/04
On Tue, 25 May 2004 20:17:27 GMT, Pat Barber
<[email protected]> wrote:
>I'll go along with the "tool maker" needing to
>use 1/64" where practical, but that comes into
>play very rarely for most folks.
>
>In the construction of a cross-cut sled, measuring
>isn't really needed as much as being able to produce
>a "square edge", which can be done, with very little
>in the way of measuring....
>
yabbut.... the guy has some nice machinist grade measuring stuff and
likes to use it. there sure ain't no harm done by dialing in a
crosscut sled and the method he described is easy, fast and
accurate....
"Bob Martin" wrote in message
> sorry if my reminder that not everyone here is a USian upset you - it
> certainly wasn't meant to.
That it did NOT, Bob ... it had nothing to do with your remark, which I must
of overlooked in any event, sorry.
It just so happens I was listening to NPR on the shop radio this morning
(all the other stations are either in their bi-annual menstrual cycles,
bleeding for money, or broadcasting
paid-advertisement-live-forever-modern-snake-oil-health-potions from
Doctor's who graduated last in their class).
NPR was taking great delight, nay gloating, for the umpteenth f*cking time,
about just how much "the whole world hates Americans".
Perhaps if NPR, and the rest of the media, could comprehend just how much I
really give a shit, they'd maybe lay off, eh?
--
www.e-woodshop.net
Last update: 5/15/04
"K. B." <[email protected]> wrote in message
news:[email protected]...
> Being a newbie, with a sled on the next to-do list, was wondering if you
> used both miter slots or if you used just one? I am wondering how to get
> two rails aligned with the sled's base, with the slots, so it wont stick
> when you push the sled through the board?
There are many little tricks, but the basic philosophy is to lay the runners
in the miter slots _before_ you attach them, then position the base of the
sled on top of the runners, fastening them temporarily to the base with
small screws from the top (or alternately, with pre-positioned double sided
tape on the runners).
TIP: use your fence as a guide for the right edge of the sled base during
this above operation.
Now carefully remove the entire assembly without upsetting the position of
the runners, and permanently mount them to the bottom of the base with the
remaining screws.
The next trick is to get the back fence of the sled perpendicular to the saw
blade once the runners are in place.
The philosophy behind this is to fasten one _end_ of the fence with a screw
to the base, and the opposite end of the fence to the base through a
slightly oversize screw hole, just big enough to give you a bit of wiggle
room for adjustment on ONE end.
Screw both ends down, make a cut, flip just one of the pieces edge for edge
and see if the cut edges have a gap. If so, loosen the single screw (on the
oversized hole end of the fence) and move the fence slightly in the
appropriate direction, then re-tighten and repeat the steps until there is
no gaps between the cut edges when one is flipped.
Your fence is now aligned perpendicular with the blade. Remove the sled and
add more screws, through the base, to the fence to hold it securely in
position.
TIP: Do not glue the back fence to the base as you may have to remove all
but the original two screws at some point in the future if the parts move
due to the dimensional instability of wood.
As stated, this is just one method of many.
--
www.e-woodshop.net
Last update: 5/15/04