# Angles and setting on the miter saw



## woodnthings

*Angles and settings on the miter saw*

I have posted this info a few times here but I'd like some comments on it: The settings on the miter saw are different than the angles cut on a piece held against the back fence...except at 45 degrees where they are the same. The settings on the mitersaw must be subtracted from 90 (degrees) to obtain the actual included angle on the workpiece. Example a 22 1/2degree setting on the mitersaw produces a cut or angle on the workpiece of 67 1/2 degrees. This might be a source of confusion :blink: for folks just starting out. Same thing on the table saw, a miter gauge set to 30 degrees will result in a 60 degree cut angle on the piece. Same as the miter saw, 90 minus 30 = 60.
*So "settings" do not equal "angles".* 
A little more info while I'm here. A circle contains 360 degrees , and a triangle always contains 180 degrees, whether it is acute,(right has a 90 degree corner), or equlateral. So the sum of the included angles in any triangle will be 180 degress. And finally a 3-4-5 triangle will have a 90 degree or square corner. Any multiple of these dimensions will result in a triangle with a square corner. Example: a triangle with sides of 9, 16 and 25 will also have a square corner or 90 degrees. Or 3 squared, 4 squared and 5 squared. This is useful in the field to determine if the site layout of a building is square or rectangular. I have used 3- 100' tape measures simultaneously to do this. I hope that this is useful.:thumbsup: bill


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## Gene Howe

Thanks Bill.


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## firehawkmph

Bill,
I think you are thinking too much.:laughing: It's kind of looking at the glass of water and trying to figure out if it's half empty or half full. All depends on which way you look at it. On the miter saw, a 22 1/2 degree cut is 22 1/2 degrees, off the 90 degree setting in the middle. When doing trim work, that is the perspective I usually think in. I have never thought of the 22 1/2 cut being a 67 1/2 cut, although it is both. As long as one knows there basic geometry like you stated above, they should be able to figure it out. When I stick my protractor into a corner, I am thinking in a perfect world, it should be 90 degrees. If it is 89, then I know I am going to cut at half that, or 44.5. Again, my mind is thinking in terms of the miter saw because that is the way it is marked. Uh Oh, now I am thinking too much.:laughing: Good food for thought though,
Mike Hawkins


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## woodnthings

*thinking too much?*

Mike, you're a smart guy..... you can't think too much, your brain will not permit it. It will shut down. You will get a headache, perspire and need a case of wobbly pops to cure it! You know the guys who designed these mitersaws were thinking too much since to cut a 60 degree angle you subtract 60 from 90 to get 30...that doesn't make sense to me.. I'm just trying to make a simple angle on the workpiece...not start subtracting angles.. Try a more obsure angle like 14 1/2 degress...it hurts my brain.  Where's my calculator:blink: Let's see 90 minus 14 1/2 is ...hmmm something ending in 6 but no ... 5 1/2...75 1/2 degrees? See where I'm going with this for a beginning woodworker? Not everyone will agree, that's why I posted the thread.:yes: bill


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## firehawkmph

Bill,
I understand exactly what you are saying. It does get very confusing. That's why I try not to think too much. Most of my miter saw cutting is based around cutting casing and base, crown, shoe mold, pretty typical stuff. Pretty typical in the fact that we normally think of these cuts the way the markings are laid out on a miter saw. I guess that's probably why the manufacturers do that. When I get into a weird project, that's when I start drawing pictures on a block of wood, scratching my head alot, sit down for a few minutes, etc. Brings to mind a story from about 15 years ago. I was building a large home for a doctor. It had a hip roof system that was pretty chopped up. I had a framing crew out there that normally did a pretty good job. So one day I stop by and they are trying to figure out the exact length for the longest (main one) hip rafter on the house. They kept coming up with the wrong answer. And it wasn't something you could leave it long and trim it in place. After about an hour of head scratching, cussing, and what have you, the young guy on the crew who they treated as basically a lumber shuffler, grabs his pencil and starts sketching a bunch of triangles on a piece of plywood. He figured it out in a few minutes. His math was based on the ratio of one triangle to another (small one to a large one). The triangle sizes where based on the sizes of certain sections of the roof. Turns out he was an architecture student at Kent State, one of the local colleges. The older guys on the crew quit harassing him as much after that. Oh well, I'm heading out to the shop to finish a cabinet end for the neighbor. Simple 90 degree cuts.:laughing:
Regards,
Mike Hawkins


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## woodnthings

*That was a great little story! I can relate:*

If it weren't for my buddy coming over this AM I never would have thought about this, He's a rough carpenter/framer. I tell him about our discussion settings vs angles. He pulls out his speed square and goes " No problem, This is the same as the miter saw." I go HUH?? He goes "YAH, I always think away from 90 since 90 is plumb/vertical." I go HUH? What are all these other nos on this thing for? He goes "These are the angles if you pivot it, on the corner, marked "pivot" it gives you angles or roof pitches etc.."
I go "Let me see that thing!" Of course I've used one before, but only to cut square ends, so I never paid any attention to the rest of the numbers. He says "Yah, you get a book with it and it tells you all about it." I go " Mine never came with a book!" "I'm still a dummy on this thing!" 
AH HA! What I finally realized was this:
I come from a drafting/architectural/ cabinet maker, woodshop, background.
He comes from a rough carpenter/ framing background, but he's a great cabinet maker too.
So, it's the way I learned vs the way he learned.
I always worked with drafting triangles, 30 degrees and 45 degreees,and a protractor, so everything was always measured in terms of the included angle.
He worked with that "speed square" which measures away from 90 degrees, like a miter saw, and has the roof pitch values on it . A 7/12 roof pitch is the same as a 30 degree angle. So, it was second nature to him to cut angles on the miter saw.
So, back to my original reason for posting, and I do appreciate your comments Mikey, for those starting out with some of these tools to immediately grasp the concepts behind them might take some 'splainin Lucy. :yes: Regards back to you! bill


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## Willie T

I'm still trying to understand how your brain can shut down if you.. you... yo... y................
............................
....................................
.


.
.
.
.
................. uh... th... thin... think......... Yeah, that's it. THink 2 much!

What was I saying?:wallbash:


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## woodnthings

*Willy... R you OK bud?*

Was that a "brain fart" I heard?:blink: We can't hear you. What's your angle? Give us your settings. We'll find you. Hang in there. We have GPS and a speed square now.:yes: bill


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## Willie T

woodnthings said:


> Was that a "brain fart" I heard?:blink: We can't hear you. What's your angle? Give us your settings. We'll find you. Hang in there. We have GPS and a speed square now.:yes: bill


HELP ! I'm over here hanging off the table at 361 degrees. And I can't figure out whether to add 90 or subtract 30 to get back up on the top.  :blink: :1eye:

Request vector, direct home.


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## woodnthings

*Your vector is.... R U above or below the Equator?*

Counter Clockwise is above? I can't remember... I'll go flush the toilet and watch the swirls! This post got all side tracked apparently. And I'm not helping either! Anymore "thoughtful" comments will be appreciated. :yes: I was just thinking..... Yahoo search :
*Which way does the water swirl when you flush a toilet on the equator?*

on the northern hemosphere, the water swirls clockwise. on the souther hemosphere, it swirls counter-clockwise. What about directly on the center line ?????


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## BudK

Bill ,

Miter's !

Troublesome joints . 
I use the same tool as you + a block plane & angle gauge . Hand tools seem to work well on these elder homes .
Cutting trim .
Saves trips back to the saw .

BK


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## woodnthings

*Hey Guy!*



BudK said:


> Bill ,
> 
> Miter's !
> 
> Troublesome joints .
> I use the same tool as you + a block plane & angle gauge . Hand tools seem to work well on these elder homes .
> Cutting trim .
> Saves trips back to the saw . BK


BK, This post was less about how to make precise joints than it was about the confusion which arises over the calculation of the angles either on the miter saw or on miter gauge and how to get the proper angle cut. I think your block plane and a "shooting board" is the answer for fine tuning the cuts after we get the angles figured out.:thumbsup: Others have said "don't rely on the setting on the saws.....that it's just an gross indication".. and it could be off by 1/2 a degree or so. I really like my Incra miter gauge with the indexing pointer for angle settings. But, I'm basically "lazy" so I would like to just "Set it and Forget it" but it's never that easy. Thanks for your reply. :smile: bill


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## BudK

Gotcha , 
I had to reread your post a couple times before it sunk in to the skullmud I call a brain . :laughing:
Doing reno/restore work , I try not to find out the actual measurement of the angle . I always get in trouble when I measure stuff . I use the bevel gauge and set the saw(s) with that .

Thank you sir .:yes:


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## pace

*Compound angles for the miter saw..*

_I have been trying to find a chart of miter & bevel angles for the Compound Miter saw, similiar to the charts made for the table saw I have several of these charts and they all differ). I am trying to build a bird house with a Japanese lantern design, consisting of curves and tapered angles. Going thru a lot of wood w/o success.._


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## woodnthings

*A yahoo search for miter and bevel chart Gave this:*

I'll search again. last one "page not available!" bill


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## pace

Bill Thanks for taking the time but that chart is limited to Crown Moulding, not multi sided miters... thanks .


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## woodnthings

*new search included "compound"..*

Let's try this one:
http://clipmarks.com/clipmark/10BBAFE4-ED0D-4C75-8B48-09D82FDD6D67/
:smile: This one has a chart for different nos of sides to angle and bevel.. I find it most confusing, but it's all yours!....bill
FYI: this chart has too many charcters to copy and paste....12,300 or so...sorry


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## bigdaddy4

hi i'm new here i neen to know where to set my miter saw at for a 67.4 cut.


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## woodnthings

*See the second photo from the top*



bigdaddy4 said:


> hi i'm new here i neen to know where to set my miter saw at for a 67.4 cut.


 Your setting should be 22.5 degrees like the photo which will give you an angle on the workpiece of 67.5 degrees, close enough!:blink: bill


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## rrich

Bill,
I'm sure that you remember "Complementary Angle" from school. That is the subtract from 90° thing. 

Think of it this way with your miter saw. 

"I need a 62.5° cut. So I'm starting with a square cut (90°) and I need to cut off 22.5° to make my 62.5° cut."

Simple, Right?


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## skymaster

wood: I B thunkin that IF on the true centerline NOT the Magnetic centerline , established on the inbound heading, properly configured then the answer to your flushing dilemma should be Figure 8's LOL LOL LOL:yes:
Per Bernouli


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## garryswf

*Oh My God*

WnT,
If guys in little white coats come knocking on your door don't cry for help from any of us. 
I used to try and outthink myself too :icon_confused:


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## TomC

With all this thinking going on does anyone really believe a 9", 16", 25" triangle has a 90 degree angle?
Tom


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## rrich

TomC said:


> With all this thinking going on does anyone really believe a 9", 16", 25" triangle has a 90 degree angle?
> Tom


Tom,
You are quite correct! The magic triangle (3,4,5) or any MULTIPLE there of, has a right angle between the 3 & 4 sides. However a 9, 16, 25 triangle is NOT a multiple of the 3, 4 , 5 triangle. Actually, I think that the 9, 16, 25 gotcha is part of an old SAT test question.

In actuality, the 9, 16, 25 geometric figure is only a straight line, or two straight lines one on top of the other.


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## cabinetman

rrich said:


> Tom,
> You are quite correct! The magic triangle (3,4,5) or any MULTIPLE there of, has a right angle between the 3 & 4 sides. However a 9, 16, 25 triangle is NOT a multiple of the 3, 4 , 5 triangle. Actually, I think that the 9, 16, 25 gotcha is part of an old SAT test question.
> 
> In actuality, the 9, 16, 25 geometric figure is only a straight line, or two straight lines one on top of the other.


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## TomC

In a right triangle a2+b2=C2. I don't have a square symbol on my key pad so to 2 in a2 means a squared. What you are telling me is:

a2(9) + b2(16) = c2(25)
or
81+256=625 I don't think so!

Maybe 15, 20, 25 treiangle would have a 90 degree angle.
Tom


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## txtoolman

Of couse Tom is correct. What ever number you multiple one side by you multiply all sides by. Hense 3 x 5 = 15, 4 x 5 = 20 and 5 x 5 = 25. So a 15' x 20' right angle triangle has a 20' hypotenuse. I wasn't sure if y'all were joking or serious.


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## Bob Willing

txtoolman said:


> Of couse Tom is correct. What ever number you multiple one side by you multiply all sides by. Hense 3 x 5 = 15, 4 x 5 = 20 and 5 x 5 = 25. So a 15' x 20' right angle triangle has a 20' hypotenuse. I wasn't sure if y'all were joking or serious.


 
I think you made a typo! 25' hypotenuse!:blink:


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## rrbrown

TomC said:


> With all this thinking going on does anyone really believe a 9", 16", 25" triangle has a 90 degree angle?
> Tom


Does it have a right angle? yes. Is it a right triangle? no

Weather it's a trick question or a typo I think you all missed it. 

check it out if you disagree.


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## Bob Willing

rrbrown said:


> Does it have a right angle? yes. Is it a right triangle? no
> 
> Weather it's a trick question or a typo I think you all missed it.
> 
> check it out if you disagree.


If 9 is the square of 3, 16 is the square of 4 than 9 + 16 is 25 and if you take the square root of 25 you have 5 hence the 3x4x5 triangle which solves the Pythagorean Theorem A2 + B2 = C2 but as 9x16x25 it is a straight line. Check it out measure out 25” than layout 16” and for 9” to form a triangle it makes a straight line 25” long. The line are on top of one another.
The answer is NO it is not a triangle, NO it does not have a right angle.


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## John in Tennessee

*Is the 31.6 reading something special?*

Mine is marked like that too...


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## rrbrown

OK my fault I only looked at cabinetmans drawing and didn't check the math. I'll take my foot out of my mouth now if its ok. :laughing:

9x16x18.3576 would be the correct measurements.


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## cabinetman

rrbrown said:


> OK my fault I only looked at cabinetmans drawing and didn't check the math. I'll take my foot out of my mouth now if its ok. :laughing:
> 
> 9x16x18.3576 would be the correct measurements.



Sorry you fell for that drawing. A quick look may appear to make sense. I didn't say it was a right triangle. I didn't say anything. It represents a lesson I learned when reading plans. It's a drafting illusion so to speak where a drawing looks correct, and may be clad with dimensions that appear to support the drawing. 

For example: Do the numerical dimensions match what the details show? If dimensions are in feet and inches, are they mistaken for inches?

This is a good lesson to pay attention to details. 
IOW, just because something looks right, doesn't mean it is right.


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## TS3660

Ok folks, I'll chime in on this one. First, when I check for squarness, I don't even bother with the 3, 4, 5 thing unless I don't have a calcuator handy. But 9 of 10 times I have a calculator, so I measure the shortest leg, mark the longer leg at the same point, multiply by 1.414 and that is my hypoteneuse. Second, and this is just a neat FYI. I had a very, very old hand miter box once. It was a top of the line saw in its time, I'm sure. It had no angles marked on it. Instead, it had numbers. 3, 4, 5, 6, 8 and I think 10. For the longest time I couldn't figure out what these meant. Then one day it dawned on me. Each number meant that that was the number of sides you would get if you made an enclosed shape by cutting that particular angle. Example: If I set it to 8, my shape would have 8 sides (45 degrees on each corner.) 10 would give 10 side at 36 degrees etc.


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## John in Tennessee

*What is special about the 31.6 mark?*

That has had my curiosity stored.


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## sofalinux

_Quote:
E__xample a 22 1/2degree setting on the mitersaw produces a cut or angle on the workpiece of 67 1/2 degrees. This might be a source of confusion :blink: for folks just starting out. Same thing on the table saw, 
a miter gauge set to 30 degrees will result in a 60 degree cut angle 
on the piece. Same as the miter saw, 90 minus 30 = 60._

The situation as I see it according to the above statement is that the mitre gauges on the table saw and the mitre saw are calibrated for measuring the PIECE BEING CUT OFF, NOT THE PIECE HELD AGAINST THE FENCE. Correct?

Your right in your statement that angles can be confusing. I made it through geometry class but using this knowledge in woodworking can be very trying.


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## Dusty82

They said there would be no math...


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## TS3660

> *What is special about the 31.6 mark?*
> That has had my curiosity stored


I think, (keyword THINK) it's to do with crown molding. If you lay the board flat and set the bevel to 45 and the angle to 31.6, it will give you a miter for the corners. But I'm not 100% sure about this.


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## toolman Steve

What?????


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## WoodMark

_HELP ! I'm over here hanging off the table at 361 degrees_

Thats impossible because there are only 360 degrees in a full circle. 361 degrees would actually be only 1 degree. Also how may minutes are 1/2 degree....how many seconds? Does it help to think of 22 degrees 30 minutes and 0 seconds as 50% of 45 degrees which is 1/8 of a full circle :smile:


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## jlhaslip

John in Tennessee said:


> Mine is marked like that too...


titled: Is the 31.6 reading something special?

yes. that angle is used when cutting crown mouldings flat on the mitre saw table... there is another angle on a compound saw (39 deg???) which is used in conjunction with the 31 deg mitre angle


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## woodnthings

*This you tube explains the 38 degres and 31 degrees*





bill :thumbsup:


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## woodnthings

*for further explantion of miter saw settings*

Go here:
http://www.woodworkingtalk.com/f2/equalateral-triangle-36923/#post316355


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## Outlander

I gave up when doing moldings since I had inside and outside compound cuts. So I spent some time to make myself some templates that were nicely labelled that I used to rough in the mitre saw. BIL stole them when he was stuck


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## Al B Thayer

I paid a couple thousand for my table saw and it still came with a cheap miter gage no one could use. But that was more than 25 years ago. Oh but I see they still sell the same crappy miter gage. Some things never change. Even when they should.

Al

Friends don't let friends use stamped metal tools sold at clothing stores.


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## cabinetman

Al B Thayer said:


> I paid a couple thousand for my table saw and it still came with a cheap miter gage no one could use. But that was more than 25 years ago. Oh but I see they still sell the same crappy miter gage. Some things never change. Even when they should.
> 
> Al


Yes, and that's unfortunate. When I bought my first new Unisaw, it came with a miter gauge similar to this. A replacement gauge (OEM), is somewhere between $30 and $50. At the time there were no alternatives like now. It was a matter of not trusting the numbers. The gauge got improved slightly by adding a shopmade fence which gave it a bit more usability. Gauges were shop made set at 90° and 45°, like this 90°. 

Accuracy and versatility lead to the use of shop made sleds.








 







.


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## WillemJM

*Thx Bill*

Thanks for starting this thread, found it interesting.

Outside of the US, we covered most of this by the 6th grade in trigonometry and by 8th grade we would be working fluently with radians and degrees, the Sin rule, the Cosine rule, etc.

I never understood why one needs a computer program to calculate segments for a segmented bowl.

Using grade 7 math (overseas) for calculations including a miter saw:

Using a miter saw, for cutting segments of a segmented bowl:

Outside diameter = 15", the radius is 7.5"

If we decide to cut the pieces into 15 degree segments, we will set the miter saw precisely at 7.5 degrees, which is the angle it will actually cut into the one side of the segment.

We need a wood strip, or board approximately 1" wide.

We convert 15 degrees to radians by multiplying with Pi/180 and if we multiply that by the radius of our circle, we have the arc length (outside) of our segment.

15*Pi/180*7.5 = 1.963" which is slightly longer than what our stop should be set.

360/15 = 24, so we need 24 segments, the circumference of the bowl wil thus be 24*1.963 = 47.124"

To calculate the exact long (outside) length of the segment, for setting the stop on our miter saw, we use the Cosine rule.

a2 = b2 + c2 -2bc Cos A

b and c are the radii, while A is 15 degrees, so it follows that the exact length is 1.958"

In short, for a 15" diameter bowl (it will be slightly less than 15"), 15 degrees will give 24 segments, set the miter saw to 7.5 degrees (the angle it actually cuts onto the segment) which is half the angle of the segment it will actually cut and cut the outside length to exactly 1.958" measured with a vernier (dial) caliper.


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## Al B Thayer

WillemJM said:


> Thanks for starting this thread, found it interesting.
> 
> Outside of the US, we covered most of this by the 6th grade in trigonometry and by 8th grade we would be working fluently with radians and degrees, the Sin rule, the Cosine rule, etc.
> 
> I never understood why one needs a computer program to calculate segments for a segmented bowl.
> 
> Using grade 7 math (overseas) for calculations including a miter saw:
> 
> Using a miter saw, for cutting segments of a segmented bowl:
> 
> Outside diameter = 15", the radius is 7.5"
> 
> If we decide to cut the pieces into 15 degree segments, we will set the miter saw precisely at 7.5 degrees, which is the angle it will actually cut into the one side of the segment.
> 
> We need a wood strip, or board approximately 1" wide.
> 
> We convert 15 degrees to radians by multiplying with Pi/180 and if we multiply that by the radius of our circle, we have the arc length (outside) of our segment.
> 
> 15*Pi/180*7.5 = 1.963" which is slightly longer than what our stop should be set.
> 
> 360/15 = 24, so we need 24 segments, the circumference of the bowl wil thus be 24*1.963 = 47.124"
> 
> To calculate the exact long (outside) length of the segment, for setting the stop on our miter saw, we use the Cosine rule.
> 
> a2 = b2 + c2 -2bc Cos A
> 
> b and c are the radii, while A is 15 degrees, so it follows that the exact length is 1.958"
> 
> In short, for a 15" diameter bowl (it will be slightly less than 15"), 15 degrees will give 24 segments, set the miter saw to 7.5 degrees (the angle it actually cuts onto the segment) which is half the angle of the segment it will actually cut and cut the outside length to exactly 1.958" measured with a vernier (dial) caliper.


Thanks Willem

Posted like a true "outside of the US" snob. In short. Glad we woodheads could post something of interest to you. Any chance you could post some pics of your segmented bowl.

Al

Friends don't let friends use stamped metal tools sold at clothing stores.


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## woodnthings

Al B Thayer said:


> Thanks Willem
> 
> Posted like a true "outside of the US" snob. In short. Glad we woodheads could post something of interest to you. Any chance you could post some pics of your segmented bowl.
> 
> Al
> 
> Friends don't let friends use stamped metal tools sold at clothing stores.


Coming to Willem's defense here. Al that "snob" remark is totally uncalled for. Willem is a very smart guy, smarter than me for sure and is providing some information to the forum in a civil way and does not deserve any personal attacks. You are also a very smart and ingenious fellow and I respect both of your opinions and ideas, so let's not get into that kind of response...OK? :smile: bill

BTW our educational system used to be at the top compared to other nations, and is now near the bottom and I think that was the basis for his comment..."from outside the U.S."


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## WillemJM

woodnthings said:


> Coming to Willem's defense here. Al that "snob" remark is totally uncalled for. Willem is a very smart guy, smarter than me for sure and is providing some information to the forum in a civil way and does not deserve any personal attacks. You are also a very smart and ingenious fellow and I respect both of your opinions and ideas, so let's not get into that kind of response...OK? :smile: bill
> 
> BTW our educational system used to be at the top compared to other nations, and is now near the bottom and I think that was the basis for his comment..."from outside the U.S."


Bill, thanks for the post, but did not take any offence. Wifey is from Michigan and I always upset her when I talk about math education in the US. :shifty:

Don't think I'm a snob, but "Social Education" (Debate, state of the nation, economy etc.) in the US is way ahead of anyone else, the reason for this being such a great country. "Technical education" (Math, applied math, etc.) is not the best though.

I work with a lot of Engineers, and they think I'm crazy because we were taught to to design and calculate everyting from a fundamental basis, while they use software to get to the same answers, without really understanding the concepts.

Perhaps just getting old. :laughing:


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## Al B Thayer

When calling someone a "true snob". It's not said to be a total put down. It comes from the movies. Like Steel Magnolias had a line much like this one. It went, "spoken like a true smottass".

Nice to see you get it Willem. I'm glad to be from the stupid side of the pond and be the biggest wood snob on the forum. Which is easy to see at the bottom of my posts. Also glad I've got the smartest hands in town. Women never cared about my math skills or the lack there of.

Al B Thayer

Friends don't let friends use stamped metal tools sold at clothing stores.


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## liquid6

Currently working on some other none wood related stuff and took a break to read a little. I think the problem with a compound miter saw lies in the semantics of the base plate.

So, you notice on the base plate that the number perpendicular to the fence is 90. Technically, this should read zero. But, those engineering folk set it to 90 because the saw blade is perpendicular to the edge of the board or fence. 

If the base plate read zero, then the cut at 22.5 degrees would make total sense. As someone else said. I picture my cuts what I am removing, not what is remaining.


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## woodnthings

*an interesting article*

If reaffirms my position that the angle markings were designed for non woodworkers, rather roof and framing contractors according to the author.

http://www.thisiscarpentry.com/2011/07/29/miter-angles-miter-saws/

The use of a protractor to measure the included angle is the source of some confusion, however it is the accurate measurement of the included angle. The setting on the base plate is the *amount of the difference* from a 90 degree angle. You must "do the math" to arrive at the protractor setting. :smile:


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## FrankC

rrich said:


> Bill,
> I'm sure that you remember "Complementary Angle" from school. That is the subtract from 90° thing.
> 
> Think of it this way with your miter saw.
> 
> "I need a 62.5° cut. So I'm starting with a square cut (90°) and I need to cut off 22.5° to make my 62.5° cut."
> 
> Simple, Right?


Not too simple when the cut is 5 degrees off. 62.5 + 22.5 = 85 :smile:


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## Alchymist

cabinetman said:


> Sorry you fell for that drawing. A quick look may appear to make sense. I didn't say it was a right triangle. I didn't say anything. It represents a lesson I learned when reading plans. It's a drafting illusion so to speak where a drawing looks correct, and may be clad with dimensions that appear to support the drawing.
> 
> For example: Do the numerical dimensions match what the details show? If dimensions are in feet and inches, are they mistaken for inches?
> 
> This is a good lesson to pay attention to details.
> IOW, just because something looks right, doesn't mean it is right.


Somtimes it is just plain obtuse. :laughing:


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