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Thread: Trigonometry !

  1. #1
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    Question Trigonometry !

    Hi Guys,

    A confession ! Trigonometry is not a strong point of mine !

    I'm trying to work out the ramp angle in order to move 10 Thou (0.25 mm) per mm over a 12 mm long slope. I keep getting 14 degrees ! That seems wrong somehow.

    Would some kind soul put me right, please !

    Thanks.
    Best Regards:
    Baron J.

  2. #2
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    Baron

    I am not clear what you are asking, but that is irrelevant.

    Go to this link https://www.omnicalculator.com/math/...gle-side-angle or google triangle calculator.

    Put in the two known values and it will give you the rest.

    Steve

  3. #3
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    I think you need a bit more info. And clarification of what you have written.

    Trigonometry Calculator

    12mm ramp- is side c 12mm long (the hypotenuse), or side b?
    Assuming you want to find angle A

  4. #4
    Boringgeoff is offline Try not to be late, but never be early.
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    BJ,
    I think 14 degrees is correct. You're looking at 3mm rise over a distance of 12mm. I just multiplied both numbers by ten (30mm -120mm) drew it on a piece of paper and measured with a compass and got 14 degrees.

    Cheers,
    Geoff.

  5. #5
    BobL is offline Member: Blue and white apron brigade
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    0.25mm, in 1 mm

    if the 12 mm is the hypotenuse
    The "inverse tangent" of that is 14.04

    If the 12 mm is the adjacent side
    The "inverse sine" of that is 14.47

    I think either might do.

  6. #6
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    I can interpret the OP in 2 ways (prob both wrong);

    angle.jpg

    SOH => Sin X = 0.25/12 therefore X = 1.19*


    OR

    angle2.jpg

    SOH => Sin X = 0.25/1 therefore X = 14.48* and Y = 3.00mm

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  8. #8
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    Wow ! You guys are brilliant !

    Many thanks for the confirmation that I'm right. 14.04 to 14.06 degrees is what I calculated. Eventually

    What I was trying to do was to work out how far up the slope I had to go to get a 10 thou change in height. The logic behind it is I want to use an M6 thread to obtain a ten thou per turn movement. So having two ramps back to back and pushing one ramp up the other will give me a 10 thou change in height.

    I hope that this makes sense !

    Thank you all for the help I owe you all a beer
    Best Regards:
    Baron J.

  9. #9
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    Quote Originally Posted by BobL View Post
    if the 12 mm is the hypotenuse
    The "inverse tangent" of that is 14.04
    Bob,
    the hypotenuse isn't used in the tangent calculation. It's opposite over adjacent (TOA)

    Quote Originally Posted by BobL View Post
    If the 12 mm is the adjacent side
    The "inverse sine" of that is 14.47
    The adjacent side isn't used in the sine calculation. It's opposite over hypotenuse (SOH)

    If you can remember "sock it to her" (SOH CAH TOA), you'll never mess it up again.
    Chris

  10. #10
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    Quote Originally Posted by Mk1_Oz View Post
    SOH => Sin X = 0.25/1 therefore X = 14.48*...
    14.48* is the correct answer.
    Chris

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