I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon. A table saw with blade tilted at 45 degrees won't do
it. How do I cut the corners off?

"GrayFox" wrote in message
...

I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon.

A table saw with blade tilted at 45 degrees won't do
it.

Why?

CW wrote:
"GrayFox" wrote in message
...


I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon.


A table saw with blade tilted at 45 degrees won't do
it.


Why?


I'll second that.... Why would it not work?

On Sat, 14 Apr 2007 19:10:24 -0500, Jody wrote:

CW wrote:
"GrayFox" wrote in message
...


I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon.


A table saw with blade tilted at 45 degrees won't do
it.


Why?


I'll second that.... Why would it not work?

Cause it is eight sided, divide 360 buy 8 then by 2 and your answer
lies there. (Hint there are 16 ends to eight sticks)

Mark
(sixoneeight) = 618

And what does this have to do with making an octagon on a table saw, and why
can't you put the blade to 45 degrees and run all four sides through? Seems
pretty simple to me.

"Markem" wrote in message
...
On Sat, 14 Apr 2007 19:10:24 -0500, Jody wrote:

CW wrote:
"GrayFox" wrote in message
...


I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon.


A table saw with blade tilted at 45 degrees won't do
it.


Why?


I'll second that.... Why would it not work?

Cause it is eight sided, divide 360 buy 8 then by 2 and your answer
lies there. (Hint there are 16 ends to eight sticks)

Mark
(sixoneeight) = 618

Check again and get back to us.

"Markem" wrote in message
...
On Sat, 14 Apr 2007 19:10:24 -0500, Jody wrote:

CW wrote:
"GrayFox" wrote in message
...


I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon.


A table saw with blade tilted at 45 degrees won't do
it.


Why?


I'll second that.... Why would it not work?

Cause it is eight sided, divide 360 buy 8 then by 2 and your answer
lies there. (Hint there are 16 ends to eight sticks)

Mark
(sixoneeight) = 618

On Sun, 15 Apr 2007 01:13:41 GMT, "Scott"
wrote:

And what does this have to do with making an octagon on a table saw, and why
can't you put the blade to 45 degrees and run all four sides through? Seems
pretty simple to me.

Well let see an octagon has eight sides not four. Perhaps the angle is
22.5? Or is your mind totally stuck in the box.

(Hint 45 + 45= ?) and #2 (22.5 + 22.5 = ?)

Mark
(sixoneeight) = 618

I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon. A table saw with blade tilted at 45 degrees won't do
it. How do I cut the corners off?

If you are trying to make a 15" long part that is octagonal in cross
section, than I don't see why tilting the blade to 45 won't do it...if fact,
it's the only way I can think of to do it without breaking out the hand
planes.

IF, on the other hand, you are trying to make a FRAME that has eight sides
and the pieces that make up the frame are 4"square, than you wouldn't tilt
the blade, rather you would set you miter gage to 22 1/2 degrees and cut the
end of the blank off, rotate the part 180 degrees and make a cut to get your
first segment. Rotatecutrotatecut repeat...you should get the picture

Oh...the segments really need to be the same length and exactly 22 1/2
degrees to come out right.

OK...I just did a little layout in AutoCadd and unless you have a way to cut
with zero kerf, this won't work because you don't have enough stock.

However, if you take your stock down to 3 3/4, you can just make it, if you
use a thin kerf saw blade...your segment s will be a little under 3 1/8"
wide...3.1066" to be precise.

Good luck
Mike

On Sun, 15 Apr 2007 01:24:06 GMT, "CW" wrote:

Check again and get back to us.

Nope just need to recalibrate the visual thought processes from making
a octagonal box to an octagonal solid stick.

(Been under the kitchen sink with a rodder and it is still stopped up)

Yep that would work.

Better?

But I think I would use the bandsaw.

Mark
http://home.mchsi.com/~xphome/

Well let see an octagon has eight sides not four. Perhaps the angle is
22.5? Or is your mind totally stuck in the box.

Yes, an octagon has 8 sides and it has 8 equal angles. The angles in a
polygon have to add up to 360 degrees. Divide 360 by 8 and you get -- wait
for it -- 45 degrees.

If the O.P. wants to turn a length of 4" x 4" (true dimension) stock into an
octagon, he needs to measure one inch from the edge, tilt his table saw
blade to 45 degrees and set the fence so the blade hits that one-inch mark,
run the piece, then repeat the cut three more times, rotating the piece 90
degrees each time. If he's using a 4x4 (IOW, a piece that's actually 3.5" x
3.5") he needs to make his mark at 7/8" instead of 1".

Lee


--
To e-mail, replace "bucketofspam" with "dleegordon"

_________________________________
Lee Gordon
http://www.leegordonproductions.com

45 it is.

"Markem" wrote in message
...
On Sun, 15 Apr 2007 01:13:41 GMT, "Scott"
wrote:

And what does this have to do with making an octagon on a table saw, and
why
can't you put the blade to 45 degrees and run all four sides through?
Seems
pretty simple to me.

Well let see an octagon has eight sides not four. Perhaps the angle is
22.5? Or is your mind totally stuck in the box.

(Hint 45 + 45= ?) and #2 (22.5 + 22.5 = ?)

Mark
(sixoneeight) = 618

Sat, Apr 14, 2007, 11:22pm (EDT+4) (GrayFox) doth
sayeth:
I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon. A table saw with blade tilted at 45 degrees won't do
it. How do I cut the corners off?

I 'guess' you could call that an octagon. Then set the table saw
at some other angle. Or you could plane it. Me, I'd probably make a
planer sled to do it, more fun that way.

From The Collaborative International Dictionary of English v.0.48
(gcide)
Octagon \Oc"ta*gon\, n. [Gr. ? eight-cornered; 'okta- (for 'oktw` eight)
+ ? an angle: cf. F. cctogone.] 1. (Geom.) A plane figure of eight sides
and eight angles. [1913 Webster]
2. Any structure (as a fortification) or place with eight sides or
angles. [1913 Webster]
{Regular octagon}, one in which the sides are all equal, and the angles
also are all equal. [1913 Webster]
From WordNet (r) 2.0 (wn)
octagon n : an eight-sided polygon



JOAT
I have anal glaucoma. I can't see my ass going to work today.

"Markem" wrote in message
...
On Sun, 15 Apr 2007 01:13:41 GMT, "Scott"
wrote:

And what does this have to do with making an octagon on a table saw, and
why
can't you put the blade to 45 degrees and run all four sides through?
Seems
pretty simple to me.

Well let see an octagon has eight sides not four. Perhaps the angle is
22.5? Or is your mind totally stuck in the box.

(Hint 45 + 45= ?) and #2 (22.5 + 22.5 = ?)


Have you ever cut a bevel on a TS??? I am not sure what your formula
represents but it has nothing to do with cutting an octagon out of a square.

8*45=360. Since cutting 1/3 width off at the corners creates 2, 45 degree
angles, you need only rotate the piece 90 degrees 3 times and cut after the
first 45 degree cut.

"Lee Gordon" wrote in message
. ..
Well let see an octagon has eight sides not four. Perhaps the angle is
22.5? Or is your mind totally stuck in the box.

Yes, an octagon has 8 sides and it has 8 equal angles. The angles in a
polygon have to add up to 360 degrees. Divide 360 by 8 and you get --
wait for it -- 45 degrees.

If the O.P. wants to turn a length of 4" x 4" (true dimension) stock into
an octagon, he needs to measure one inch from the edge, tilt his table saw
blade to 45 degrees and set the fence so the blade hits that one-inch
mark, run the piece, then repeat the cut three more times, rotating the
piece 90 degrees each time. If he's using a 4x4 (IOW, a piece that's
actually 3.5" x 3.5") he needs to make his mark at 7/8" instead of 1".


Actually you want the 45 degree bevel to begin at 1-11/64" from each corner,
leaving 1-21/32" in the center for actual 4x4.

In article .net,
"CW" wrote:

"GrayFox" wrote in message
...

I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon.

A table saw with blade tilted at 45 degrees won't do
it.

Why?

Because when the blade is tilted at 45 degrees, the diameter of the
blade is not big enough to reach thru the top of the 4" square cross
section.

In article ,
"Leon" wrote:

"Lee Gordon" wrote in message
. ..
Well let see an octagon has eight sides not four. Perhaps the angle is
22.5? Or is your mind totally stuck in the box.

Yes, an octagon has 8 sides and it has 8 equal angles. The angles in a
polygon have to add up to 360 degrees. Divide 360 by 8 and you get --
wait for it -- 45 degrees.

If the O.P. wants to turn a length of 4" x 4" (true dimension) stock into
an octagon, he needs to measure one inch from the edge, tilt his table saw
blade to 45 degrees and set the fence so the blade hits that one-inch
mark, run the piece, then repeat the cut three more times, rotating the
piece 90 degrees each time. If he's using a 4x4 (IOW, a piece that's
actually 3.5" x 3.5") he needs to make his mark at 7/8" instead of 1".


Actually you want the 45 degree bevel to begin at 1-11/64" from each corner,
leaving 1-21/32" in the center for actual 4x4.

I probably didn't really make myself clear on my setup. My table saw
blade tilts to the right and my fence is on the right.

Perhaps I'm missing something, but if I try to run the stock through the
table saw and cut off the lower right corner of the cross section, that
seems like an extremely dangerous cut to make. The cutoff piece would
be against the fence.

If I can move the fence to the left side of the blade, it would be a
much safer cut. But, I don't think I can do that.

"Lee Gordon" writes:
Yes, an octagon has 8 sides and it has 8 equal angles. The angles
in a polygon have to add up to 360 degrees. Divide 360 by 8 and you
get -- wait for it -- 45 degrees.

If you have eight sides, you have *sixteen* cuts (two on each board -
one at each end). Divide 360 by 16 and you get 22.5.

Plus, the angles of a polygon do not add up to 360. They add up to
180(n-2) where n is the number of vertexes. The *bevels* add up to
360, with '0' meaning unbeveled (square cut end).

"GrayFox" wrote in message
...

I probably didn't really make myself clear on my setup. My table saw
blade tilts to the right and my fence is on the right.

Perhaps I'm missing something, but if I try to run the stock through the
table saw and cut off the lower right corner of the cross section, that
seems like an extremely dangerous cut to make. The cutoff piece would
be against the fence.

If I can move the fence to the left side of the blade, it would be a
much safer cut. But, I don't think I can do that.

OK, that makes much more sense. Most right tilt saws will let you move the
fence to the left side of the fence 8-12" and that would be the way to do
it.

Or use a 45 degree chamfer bit on a router.

On 4/15/07 11:00 AM, "GrayFox" wrote:


I probably didn't really make myself clear on my setup. My table saw
blade tilts to the right and my fence is on the right.

Perhaps I'm missing something, but if I try to run the stock through the
table saw and cut off the lower right corner of the cross section, that
seems like an extremely dangerous cut to make. The cutoff piece would
be against the fence.

If I can move the fence to the left side of the blade, it would be a
much safer cut. But, I don't think I can do that.

Personally, I wouldn't sue the fence in that situation, at least not having
the work piece running continually along the fence. I would use either a
miter gauge with an extension fence and a stop block to get the length, or a
cutoff sled. If you want to use the fence for position, I would add a
temporary fence piece that is entirely in front of the blade. Hold the work
against the miter gauge with the end touching the temporary fence and then
move through the cut. As you bring the work to the blade, the cutoff would
no longer be against the fence and there would be less chance of it binding
up.

On Sun, 15 Apr 2007 14:49:18 GMT, GrayFox wrote:

In article .net,
"CW" wrote:

"GrayFox" wrote in message
...

I have a 4" square piece of wood that is 15" long. I need to make it
into an octagon.

A table saw with blade tilted at 45 degrees won't do
it.

Why?

Because when the blade is tilted at 45 degrees, the diameter of the
blade is not big enough to reach thru the top of the 4" square cross
section.

Do you have access to a bandsaw with a fence? Or perhaps a new tool is
needed.

Mark

Sun, Apr 15, 2007, 11:10am (DJ*Delorie) doth
proclaimeth:
If you have eight sides, you have *sixteen* cuts (two on each board -
one at each end). Divide 360 by 16 and you get 22.5. snip

Wow, impressive, that must be some of that new college math -
calcluclueless, eh? I learned the old fashioned math, where if you had
a square (four equal sides), and knocked off the four corners (which
would be four cuts), you'd get an octagon (eight sides). I'm always
ready to learn somthing new - so how about learning me where you came up
with the extra cuts?



JOAT
I have anal glaucoma. I can't see my ass going to work today.

If I can move the fence to the left side of the blade, it would be a
much safer cut. But, I don't think I can do that.

I've never seen a table saw that didn't allow for the fence to be moved to
either side of the blade. You are correct that making the cut you described
on a right-tilt saw with the fence to the right of the blade is an
invitation to a kickback. But you ought to be able to completely lower the
blade, slide the fence to the left, raise the blade back up, tilt it to 45
degrees, and proceed with the operation. You'll just be doing it
"backwards" from the way those of us with left-tilt saw would do it.

Do you have a jointer? You could try tilting it's fence to 45 degrees and
nibbling the stock away 1/16" at a time. Of course, that would take
practically forever. g

Lee

--
To e-mail, replace "bucketofspam" with "dleegordon"

_________________________________
Lee Gordon
http://www.leegordonproductions.com

If you have eight sides, you have *sixteen* cuts (two on each board -
one at each end). Divide 360 by 16 and you get 22.5.

That's true if you are constructing a hollow octagon out of eight individual
pieces. The ends of each of those pieces are cut at 22.5 degrees because it
takes two of them to form the necessary 45 degree angle. But the O.P. isn't
trying to assemble an octagonal-shaped "ring." He is looking to cut a solid
octagon out of a solid square by clipping each of the four corners off the
square. To do that, he needs to set his blade to 45 degrees.

Lee

--
To e-mail, replace "bucketofspam" with "dleegordon"

_________________________________
Lee Gordon
http://www.leegordonproductions.com

Actually you want the 45 degree bevel to begin at 1-11/64" from each
corner,
leaving 1-21/32" in the center for actual 4x4.

You're right. I flip-flopped the two equal sides with the hypotenuse.
(Would have made measuring easier, though. g)

Lee

--
To e-mail, replace "bucketofspam" with "dleegordon"

_________________________________
Lee Gordon
http://www.leegordonproductions.com

GrayFox wrote:

| I have a 4" square piece of wood that is 15" long. I need to make
| it into an octagon. A table saw with blade tilted at 45 degrees
| won't do it. How do I cut the corners off?

I have a right-tilt saw, too, and I think I'd be tempted to clamp a
two-by to the table on the left side of the blade to serve as a
temporary fence. I'd use the normal fence for positioning and
alignment, then move it out of the way when I made the cuts...

Thank you *so* much for not wanting to cut a nonagon!

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

In article ,
"Morris Dovey" wrote:

GrayFox wrote:

| I have a 4" square piece of wood that is 15" long. I need to make
| it into an octagon. A table saw with blade tilted at 45 degrees
| won't do it. How do I cut the corners off?

I have a right-tilt saw, too, and I think I'd be tempted to clamp a
two-by to the table on the left side of the blade to serve as a
temporary fence. I'd use the normal fence for positioning and
alignment, then move it out of the way when I made the cuts...

Thank you *so* much for not wanting to cut a nonagon!


LOL!

I had just about come to that conclusion myself! Thanks.

In article ,
"Lee Gordon" wrote:

If I can move the fence to the left side of the blade, it would be a
much safer cut. But, I don't think I can do that.

I've never seen a table saw that didn't allow for the fence to be moved to
either side of the blade. You are correct that making the cut you described
on a right-tilt saw with the fence to the right of the blade is an
invitation to a kickback. But you ought to be able to completely lower the
blade, slide the fence to the left, raise the blade back up, tilt it to 45
degrees, and proceed with the operation. You'll just be doing it
"backwards" from the way those of us with left-tilt saw would do it.

Do you have a jointer? You could try tilting it's fence to 45 degrees and
nibbling the stock away 1/16" at a time. Of course, that would take
practically forever. g

Lee

I tried that, but my fence has a big old piece (the clamping mechanism)
on the right side of the fence. That leaves no infeed area.

The jointer approach is probably the safest way to do this job even
though it'd just be nibbling away. There's only 4 cuts that need to be
made.

"Lee Gordon" wrote in message
news
Actually you want the 45 degree bevel to begin at 1-11/64" from each
corner,
leaving 1-21/32" in the center for actual 4x4.

You're right. I flip-flopped the two equal sides with the hypotenuse.
(Would have made measuring easier, though. g)


I cheated and used a CAD program.

"Morris Dovey" wrote in message
...
GrayFox wrote:

| I have a 4" square piece of wood that is 15" long. I need to make
| it into an octagon. A table saw with blade tilted at 45 degrees
| won't do it. How do I cut the corners off?

I have a right-tilt saw, too,

So do I and I have done this operation many times by using a piece of scrap
as a sacrificial fence on the face of the normal RH fence.

Tim W

On Apr 15, 10:41 am, "Morris Dovey" wrote:

I have a right-tilt saw, too, and I think I'd be tempted to clamp a
two-by to the table on the left side of the blade to serve as a
temporary fence.

Exactly so. Or better, a 4x4 for the temporary fence (so that
the last cut has some workpiece-to-fence contact area).

It's tremendously useful sometimes to have a plywood
fabricated straightedge, 'cuz those of us without jointers
can't find straight edges in a lumber pile.