# Cutting angle



## johnisback (Feb 25, 2015)

I have a 1" x 6" x 6' . I want the bottom to be level, desired height at the end of the board reduces to 2.75", how do I determine the cut angle ?


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## Hammer1 (Aug 1, 2010)

1x6" are not always exactly 6". Sounds like you want to cut a taper on the board from 6" +- to 2.75" over the 6' length. Are you tapering one edge or both? Normally, the ends of the board would be cut at 90 degrees. In relation to the floor the untapered edge would be vertical, therefore, the 90 degree cuts. If you are tapering one edge and want that vertical, simply mark the tapered cut line and square off that.


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## woodnthings (Jan 24, 2009)

*assuming a double taper*

That is a taper on each edge to a square top and bottom.
Find your center line and scribe it on both ends.
measure out 1/2 of 2.75" on the top which would be 1.375" from each side of center.
Measure the bottom, which should be 2.25" from each side of center, assuming a 5.5" wide board (1 X 6)
Those are your cut lines.

If you need the angle in degrees, you can subtract 1.375 from 2.25 to get a zero line which is 0.875.
You now have a triangle with a base of 72" and a side opposite of .875" 
.875 divided by 72 is the TAN of the desired angle, which is 0.01215, which corresponds to an angle less than 1 degree, about 40 minutes of angle or if all my calcs are correct, 0.69 degrees.

see the airplane example here:
http://www.mathsisfun.com/algebra/trig-finding-angle-right-triangle.html


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## Steve Neul (Sep 2, 2011)

For a taper like that you don't need to know the angle, just go by the measurements, mark it and cut it.


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## GeorgeC (Jul 30, 2008)

Steve Neul said:


> For a taper like that you don't need to know the angle, just go by the measurements, mark it and cut it.


This is the correct answer ASSUMING. That is assuming that the original poster has the board standing on edge. He also did not specify where the taper was to start therefore an angle cannot be provided.

Too little information by original poster.

George


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## woodnthings (Jan 24, 2009)

*just give him an answer...*



GeorgeC said:


> This is the correct answer ASSUMING. That is assuming that the original poster has the board standing on edge. He also did not specify where the taper was to start therefore an angle cannot be provided.
> 
> *Too little information by original poster.*
> 
> George


Just provide an answer even if it's wrong. Let him sort it out and take which ever one applies. I really can't imagine tapering a 1 X 6 down it's surface. The other replies also "assumed" it was on the edges, so we are either all wrong or there is the other remaining way ..... :blink:

Here's a chance to use all your engineering skills and math/trig to provide an answer ... even if it's wrong.
I did my best and I'm a Industrial Designer, not a rocket scientist. :no:


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## Ghidrah (Mar 2, 2010)

The request sounds pretty cryptic to me. Wants the bottom to be level relative to what, gravity, table, mantle, a picture on the wall the ocean? As most use LxWxH, 72x6x.75. Assuming "end", (common vernacular) is relative to length then it would be opposing end of the 6' line. So one end would be 6" wide and the other would be 2.75 wide while laying on the flat, .75. Now after many years dealing with custs I've learned many can see what they want in their mind even when they can't put it into words that they, let alone someone else can understand. 

My wife is a hair dresser and suffers from the same issue with custs. 

I want it to look like the blond woman in the movie with the crazy boyfriend that looks like Alfred E. Newman, you know. What movie? Oh I don't know it was at the theater last Wed. Who was the actress? I don't know her name but she was in that other movie last year. (This is no joke but an actual conversation in a consultation.

If johnisback needs an angle for some other project more info would be nice, because there's no need to know the angle to cut a straight line between 6 and 2.75 but a straight edge would be nice.


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## woodnthings (Jan 24, 2009)

*now that there was really helpful ^*

when you don't have an answer, bring in the beauty salon, they will certainly have a solution.....:blink:

How many ways can you taper a board? 
along it length or across it's width' Let's rule out width by the description.

OK along it's length in plan view or side view, that is along the surface or along the edges. Let's rule out along the surface, just not practical, possible yes, but almost impossible using common tools except the bandsaw.


OP states:
I have a 1" x 6" x 6' . I want the bottom to be level, desired height at the end of the board reduces to 2.75", how do I determine the cut angle ?

So along the edges remains. "desired height" as in tall should be 2.75". "bottom to be level" no confusion there, level is level using a bubble level will tell you when it's level. All the rest is either simple layout or rather simple trigonometry. I rest my case. Overthinking results in unnecessary complications. JMO


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## bauerbach (Mar 25, 2012)

Practical answer, you cannot extend any angle across a 6' span with any prayer of a decent result. Our capability to measure/mark would produce an unacceptable variance at the far end.

If you really must know, the answer is SOH CAH TOA. Tangent is your likely scenario









pull out your handy scientific calculator and do 

Tan^-1 (opposite/adjacent)

Tan^-1 (300/400) in the above example.

Perhaps for OP 

Tan^-1 (3.25/72) 
(assuming nominal 6" height, discounting 2.75" outside the triangle resulting in a 3.25" opposite dimension, and a 6'*12"=72" adjacent dimension)

The answer to that would be 
2.5845134459655798267580655924726 Degrees

But again, if your off by even hundredths or even thousandths, you wont meet at the end points.


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## Al B Thayer (Dec 10, 2011)

List in AutoCD will tell you the answer. I might check it when I return.

Two guys had three dollars...........

Al


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## Ghidrah (Mar 2, 2010)

Woodnthings
I believe I answered the members question minus the degree of angle, its a simple straight line. If the member required a degree of angle maybe he/she should have specified which angle. There are 3 incase you were unaware, 2 of which were currently unknown and I didn't need to ask a beautician for the answer.

With the info provided I find A=2.58°, B=90°, C=87.4


> Just provide an answer even if it's wrong. Let him sort it out and take which ever one applies.


 How one can justify an incorrect answer I don't know. You sound jaded.

I can think or 3 ways to taper a board.


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## bauerbach (Mar 25, 2012)

only 1 logical way to taper a 1"x6" board so that 1 end is 2.75".


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## woodnthings (Jan 24, 2009)

*not in my book*



bauerbach said:


> only 1 logical way to taper a 1"x6" board so that 1 end is 2.75".



You can "taper" all the material off one edge leaving 2.75" at the top and one square corner at the opposite edge.

OR you can taper both edges about a centerline leaving 2.75" at the top and both corners will be symetrical, and more than 90 degrees. This is the approach I took, and who knows it may be "wrong" but I posted it regardless. At least the OP can choose between several actual answers, rather than posts that criticise the replies of others. :yes:

Asking for more information does not provide an answer in my opinion, but if that's all you got, run with it.


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## nwoodward (Feb 2, 2014)

This is a common core math problem asked to 4th graders. To solve this answer you must fling poop and smash typewriters. The answer will eventually reveal itself.


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## FrankC (Aug 24, 2012)

Guess it doesn't really matter, the OP hasn't been back to clarify anything.


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## BZawat (Sep 21, 2012)

Not to be argumentative Bill (goodness knows I never argue lol), but it is totally possible - and practical - to taper a board's thickness using a hand plane. All that is needed is a gauge line around the board's edges. I've made tapered reducer mouldings for weird flooring situations like this. 

Not that I think this is what the original post was about. It was a bit ambiguous, but I was thinking he meant to taper one long edge from the board's full width down to 2.75". In which case Steve is right - it doesn't matter what the angle is. Just measure, snap a line, and cut it.


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## cave62 (Feb 16, 2015)

2.2degrees is my guess. I agree snap a line and cut it.


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## GeorgeC (Jul 30, 2008)

woodnthings said:


> Just provide an answer even if it's wrong. Let him sort it out and take which ever one applies. I really can't imagine tapering a 1 X 6 down it's surface. The other replies also "assumed" it was on the edges, so we are either all wrong or there is the other remaining way ..... :blink:
> 
> Here's a chance to use all your engineering skills and math/trig to provide an answer ... even if it's wrong.
> I did my best and I'm a Industrial Designer, not a rocket scientist. :no:


Why would provide an answer even if it is wrong? Why not find out the real question first. Too much confusion.

I have too much arthritis in my fingers to type more than necessary.


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## skyking (Mar 24, 2013)

knowing the angle does not serve ME any purpose as far as making the cut. I can't put 2.4 degrees into my table saw and Bam! done 
I suspect that the real situation is not regular either, not straight lines, etc. 
My solution (with pricey long wood) is to make a cardboard template to verify fit. Make that fit and you are going to be happy.


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