Need to figure out angle

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I need to figure out the taper angle on a piece of wood. Can someone help me out?? The piece is 18 7/16" long. The top is 1 11/16" wide and the bottom is 2 3/16" wide. What angle would I need to cut that?
Thanks
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snipped-for-privacy@gmail.com writes:

Looks like 1.5534 degrees. Note that it's often easier to build a jig with the 1/2" offset than to accurately set your saw to 1.5536 degrees.
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DJ Delorie wrote:

the grain straight with the neck, otherwise the grain will be parallel to one side.
--
Gerald Ross
Cochran, GA
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On 27 Dec 2004 11:20:45 -0800, snipped-for-privacy@gmail.com wrote:

Are you sure you really need the actual angle? Most times a job on a long-'n-thin piece is done with reference to the dimensions you gave; not the angle. For one thing, there's far too much margin for error trying to set such an angle; any error is magnified dramatically over the length of the work piece.
Also, using a bevel gauge and transferring the angle with it yields good results, too, if you're trying to fit an adjoining piece.
- - LRod
Master Woodbutcher and seasoned termite
Shamelessly whoring my website since 1999
http://www.woodbutcher.net
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snipped-for-privacy@gmail.com wrote:

Doesn't anybody know how to do simple trig anymore?
Basically you have a 1/2" taper (2 3/16 - 1 11/16") over 18 7/16" long piece
inv cosine (.5/18.4375) .44 deg.
or 1.56 deg, depending on how you want to measure it.
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I am bulding a Guitar Neck so I need that exact angle. I was going to cut it on my table saw.
snipped-for-privacy@yahoo.com wrote:

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On 27 Dec 2004 11:56:15 -0800, snipped-for-privacy@gmail.com wrote:

I've never seen a table saw with a tilt scale worth a damn.
make a test cut, nudge the saw, repeat.

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On 27 Dec 2004 11:42:48 -0800, " snipped-for-privacy@yahoo.com"

than the day I graduated HS/college/grad school.
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On 27 Dec 2004 11:42:48 -0800, " snipped-for-privacy@yahoo.com"

Doesn't anybody know how to do simple trig anymore?
Apparently some one does the second post of this thread already figured out the angle.....

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On Mon, 27 Dec 2004 23:21:31 -0800, Don Foster

The trig isn't the problem.
It's setting a taper guide to the angle I get when I crunch the numbers.
If I were setting up a machine to make the part, I'd calculate it, though I'd probably adjust my dimensions so the angle came out a round number.
This is reproducing the angle on another part, so the actual number doesn't matter so much as "getting it right."
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www.kc7nod.20m.com
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I believe that would be arctan(0.5 / (18 7/16) ) But I am curious why you need to know the angle. You can cut it from the measurements you have.
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Larry Wasserman Baltimore, Maryland
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snipped-for-privacy@gmail.com wrote:

Eyeball... :)
Seriously for a piece like that, I would simply measure where I wanted it, mark it and cut by hand w/ the bandsaw (or a skill saw if didn't have the bandsaw) and then just bring to the line on the jointer...
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Duane Bozarth wrote:

Of course, if it's a repetitive operation, a sled for the TS w/ a 1/2" offset is worth the time...
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snipped-for-privacy@gmail.com writes:

IMHO, you can't get there from here by trying to adjust some cutting tool to an angle guide.
Suggest the following:
1) Lay out the angle with a straight edge and a pencil.
2) Trim away any waste in excess of about 1/4"-1/2".
3) Clamp on a straight edge and clean up with a router and a pattern or bottom bearing, trim bit.
(I do it both ways)
HTH
Lew
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"The angle of the piece"
Anything else is trying to calculate an angle from measurements, which are necessarily imprecise, doing icky decimal arithmetic, which is also imprecise.
Instead what you do is say, "Who CARES what the *expletive deleted* angle is? I'll just set my taper jig so that it matches the workpiece."
Or the sliding bevel or whatever measuring tool is right for the job.
VERY small errors magnify greatly over the length of your piece. Measure direct and save your hair.
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U-CDK_CHARLES\Charles wrote:

Case in point, drilling a hole through a plane tote. I tried to use an absolute angle instead of just whatever in between angle the actual thing was supposed to be. I whined about the result on some other thread. Right through the side of a piece I had spent hours shaping. <sigh>
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Michael McIntyre ---- Silvan < snipped-for-privacy@users.sourceforge.net>
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On 27 Dec 2004 11:20:45 -0800, snipped-for-privacy@gmail.com wrote:

[2 3/16 - 1 11/16] / [18 7/16]is the tangent of the angle. But do as thet say, and make a jig: Nail a crosscut runner strip to plywood and cut through the saw. Lay out the piece to be cut with markings along the new cut plywood edge. Tack more runner strips to hold it in place, and run through the saw. Ain't no way I'm trying ASCII art.
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snipped-for-privacy@gmail.com wrote:

If you use a taper jig you don't need to figure out the angle. See:
http://www.newwoodworker.com/usetaperjig.html
-- Jack Novak Buffalo, NY - USA (Remove "SPAM" from email address to reply)
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On 27 Dec 2004 11:20:45 -0800, snipped-for-privacy@gmail.com wrote:

A diagram would certainly clarify, but depending on the interpretation of the "long" measurement given two calculations are provided.
For a trapezoid of height 18 7/16", the angle between the sloped sides is
(tan-1(0.25/18.4375))*2 ~= 1.5536886 degrees
For a trapezoid of side length is 18 7/16", the angle between the sloped sides is
(sin-1(0.25/18.4375))*2 ~= 1.5538314 degrees
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