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Thread: what's your reference tool for angles?

  1. #1
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    what's your reference tool for angles?

    I need to make some shooting boards for angled work - what method would you use? Precise protractor or just use compass and dividers?

    Probably need a good protractor regardless for tool setup, so I'd appreciate recommendations if you have them.

  2. #2
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    Thomas, If it is an angle that I have a drafting triangle for I would use one. If not I would use a protractor and most likely make a template of some kind, cardboard, wood, paper. Something that would lay flat and could be reused later to check the board.
    Jim

  3. #3
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    I use a protractor as a starting point (mine is Toei) but once I get setup I will adjust by making sure that cut and compliment add up to 90 degrees. You can check that with an accurate square and adjust accordingly.
    Bumbling forward into the unknown.

  4. #4
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    Maybe the camera needs a trip to the shop for pictures.

    One of my tools for finding setting angles on a piece is a Union Tools protractor on a steel rule.

    The other is a small machinist protractor. My recollection is it is made by General Tools. Though they look the same with many different brands marked on them.

    Since shooting boards were mentioned, here are a couple of links to some my angled shooting set ups:

    http://www.sawmillcreek.org/showthre...t-Eared-Donkey

    This one maybe of interest if one wants to use a single shooting board for a lot of different angles:

    http://www.sawmillcreek.org/showthread.php?244777

    It is double sided so a piece can be shot either left or right handed. There are also posts by others about their shooting boards and shooting angles.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  5. #5
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  6. #6
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    As a person with a carpentry background, my preference for dealing with angles expressed in degrees is to use trig to convert degrees into slope ratios for layout. I do however have an old B & S vernier protractor accurate to 5 minutes that I will use as a cross check. The process is to draw the angles on a pattern board and to transfer the angles with an adjustable bevel.

  7. #7
    Quote Originally Posted by Roger Nair View Post
    As a person with a carpentry background, my preference for dealing with angles expressed in degrees is to use trig to convert degrees into slope ratios for layout. I do however have an old B & S vernier protractor accurate to 5 minutes that I will use as a cross check. The process is to draw the angles on a pattern board and to transfer the angles with an adjustable bevel.
    Further to your second technique, I picked up a reference tool from Highland called a Bevel Boss which has engraved angles for 0-50 degrees in 1/4 degree increments (I think Veritas may make something similar). From the Bevel Boss, I transfer the selected angle with an adjustable bevel (mine is a Shinwa). It's proven to be a useful thing to have around and I mention it because it sounds like a purchase version of the pattern board you are capable of making using the methods you're describing.
    Last edited by Edwin Santos; 09-15-2017 at 3:43 PM.

  8. #8
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    IMAG0058.jpg
    Needed these for the ends of a lid. Angle was marked with a sliding bevel gauge. Used that to set a saw's angle...
    IMAG0057.jpg
    Once a few grooves were made..
    IMAG0067.jpg
    I could then match the angle to the edge, with a small plane..
    IMAG0069.jpg
    To make a lid for a tool box..
    side view.jpg
    YMMV

  9. #9
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    Edwin, since the question was for reference, I am suggesting the most precise method at my command is to layout in slope. So am using a suite of tools, a straight edge, dividers, reference ruler, knife and HP calculator. The calculator provides resolution of both angle and slope to a degree beyond molecular scale. A reference scale yields dimensions to 1/100 inch, that a sharp pointed divider can transfer. So in theory, with a constant base, each inch of rise defines 100 specific slopes. If a base of 12 inches is used 0 to 45 degrees can be expressed in 1200 unique increments. No other method that I know of can yield such control with common tools. For instance the Brown and Sharpe protractor yields 540 divisions to 45 degrees. As a practical matter, the B & S is good enough and most direct. With the calculator divider method, a number of physical steps are involved and inaccuracy can accumulate with the number of steps. With care accurate angles can be reproduced for reference well beyond single degree protractors.

  10. #10
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    Incra protractor http://www.incra.com/measuring_marki...lty_rules.html

    Working on the theory that a bigger protractor gives a better resolution, an 18" protractor https://www.summitracing.com/int/par...2191/overview/
    Chris

    Everything I like is either illegal, immoral or fattening

  11. #11
    I agree with Roger Nair in his recommendation of trigonometry, in particular tangent (angle) = rise divided by run. There is no protractor that can give comparable accuracy. With the calculators available today, almost anyone can find the tangent of a desired angle or the angle of a particular rise/run ratio. Lay out the angle on a piece of paper and then copy it to the largest sliding bevel you have (or make a temporary one out of two steel straightedges). I also use drafting triangles and the Veritas stainless steel protractor. But the most direct and most accurate method is trig. I will admit -- if you are trying to make polygons that close seamlessly, some tweaking may still be necessary. But trig plus a sliding bevel with get you the closest of any method I know.

    Doug

  12. #12
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    I use trig, a framing square and a straight edge to lay out any angle.

    Jim
    Ancora Yacht Service

  13. #13
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    I have a sliding bevel for transferring angles. As for specific angles, it depends on the angle:

    1) Combination square for 90 and 45.
    2) Compass and straight edge for geometric figures and bisecting angles.
    3) Carpenters (and smaller versions) square for other angles, which are 'here to there' as well as known slopes like 1:7 (dovetails etc).

  14. #14
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    Quote Originally Posted by John Schtrumpf View Post
    1) Combination square for 90 and 45.
    I also use a protractor like this, a useful addition for combo square users, cast iron:

    61eErrBe-HL._SL1000_.jpg

    This one is Starrett but they are available with and for other combination squares. Some have a built-in bubble level which is handy on occasion.

    JKJ
    Attached Images Attached Images

  15. #15
    Quote Originally Posted by Roger Nair View Post
    Edwin, since the question was for reference, I am suggesting the most precise method at my command is to layout in slope. So am using a suite of tools, a straight edge, dividers, reference ruler, knife and HP calculator. The calculator provides resolution of both angle and slope to a degree beyond molecular scale. A reference scale yields dimensions to 1/100 inch, that a sharp pointed divider can transfer. So in theory, with a constant base, each inch of rise defines 100 specific slopes. If a base of 12 inches is used 0 to 45 degrees can be expressed in 1200 unique increments. No other method that I know of can yield such control with common tools. For instance the Brown and Sharpe protractor yields 540 divisions to 45 degrees. As a practical matter, the B & S is good enough and most direct. With the calculator divider method, a number of physical steps are involved and inaccuracy can accumulate with the number of steps. With care accurate angles can be reproduced for reference well beyond single degree protractors.
    That's pretty accurate. I'd love to watch you do it. Thanks for the additional explanation,

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