Slide Rule CF/DF and CI scales

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  • Опубліковано 5 лис 2024

КОМЕНТАРІ • 15

  • @sliderulesandmathematics9232
    @sliderulesandmathematics9232  7 місяців тому +5

    Note, this is a revision of an earlier video incorporating the virtual slide rule. I just thought it had better clarity and was more concise.

  • @martinfiedler4317
    @martinfiedler4317 7 місяців тому +6

    You are great! Here you answer the question that your last vid raised for me: How using the folded scale work.
    So when I go to CF, I simply put its index on 4 * Pi.
    Going to 6 on CF I get 4 * Pi / 6.
    And when I look back to D, I divide by Pi to get the result of 4 * 6.
    Ingeniously simple actually...

    • @sliderulesandmathematics9232
      @sliderulesandmathematics9232  7 місяців тому +3

      it really is, and a great tool to teach folks how to visualize numbers and relationships between them. That is why I have a 7 foot long N-500. For teaching logs and trig.

  • @JohnLeePettimoreIII
    @JohnLeePettimoreIII 7 місяців тому +3

    when i was first learning how to use a slide rule, the inverted scales were the most difficult for me to fully grasp. i could wrap my head around the concept just fine. but the practical use of the scales in calculations gave me fits. even now, when i need to use the inverted scales i have to briefly shut my eyes, take a breath and think to myself, *_"You got this, buddy."_*

    • @sliderulesandmathematics9232
      @sliderulesandmathematics9232  7 місяців тому +1

      When I look at an equation the first thing I do is say to myself, 'math problem, who's your daddy'. Then I take it down as easily as taking down a flerf that can't see the curve.

    • @sliderulesandmathematics9232
      @sliderulesandmathematics9232  7 місяців тому +2

      Which scale you use is like a golfer seeing the line on a putt. It takes experience but it just jumps out at you after awhile.

  • @barryporter6993
    @barryporter6993 7 місяців тому +3

    my head hurts :):). But I think I understand :)Thanks

  • @erwanthomas
    @erwanthomas 7 місяців тому +4

    hello, there is something that I don't grasp.
    lets call C and D adjacent (because they touch each other) same for CF and DF
    and D and CF opposite, same for C and DF.
    if I set the index of C over 2 on D ( adajcent) I can read the result of any calculation on the adjacent scale so I can pick any number on C get the result on D or pick a number on CF and read the result on DF.
    but if I take the index from the opposite scale meaning align 2 from D with 1 from CF i will read the result on the opposite scale but only for numbers from CF, numbers from C won't work with DF,
    Why is that? Why is it not symetric?

    • @sliderulesandmathematics9232
      @sliderulesandmathematics9232  7 місяців тому

      Good question let me have a look

    • @sliderulesandmathematics9232
      @sliderulesandmathematics9232  7 місяців тому +1

      Ok now that I’m not driving and can see exactly what your question is… when you align the index of c you are keying it to the index of cf. If you go from d to cf you are keying to pi on d. As a result you get 6.28 on d

    • @erwanthomas
      @erwanthomas 7 місяців тому +1

      @@sliderulesandmathematics9232 sorry for my poor english but that's not it.
      if I want to multiply by 2
      I can align 1 on C with 2 on D then when I read 2 on C I can read 4 on D or I can read 8 on CF and read 16 on DF.
      or I can align 1 on CF with 2 on DF then if I read 4 on CF it gives me 8 on DF and if I read 3 on C I can read 6 on D.
      if the index is adjacent I can use both scales.
      now if I align 1 on CF with 2 on D if I read 2 on CF i can read 4 on D but if i read 4 on C i read under 7,9 on DF; if I read 2 on C I get 3,96 on DF

    • @sliderulesandmathematics9232
      @sliderulesandmathematics9232  6 місяців тому

      @@erwanthomas with 1 on c and 2 on d I don't read 8 or 16 on cf/df. With 1 on cf and 2 on df it is correct to read 4/8 on cf/df. I am not getting the values you state when going across scales. I think you may be confusing the scales and misreading them.

    • @erwanthomas
      @erwanthomas 6 місяців тому +1

      @@sliderulesandmathematics9232 I've check on a decilon and an hemmi 260.
      If I put 1 on c and 2 on D, c goes from 1 to five (2x5=10) above 1 on c you have PI on CF and 2PI on df and CF goes up to 10xPI/2 and give you 10xPI the decilon goes up to 16 on CF because DF goes up to 3*2.
      so 8 on CF is above 5,1 on D and gives 1,6 on DF . which is expected because that's what folded scales are for. extend c and D witout having to move the slide too much.
      it's when you put 1 from CF with 2 on D that only numbers from CF give you the right answer on D but not from C to DF. that's where lies the mystery.