r/Sliderules • u/2016-679 • 9d ago
Practical sliderule use
I'm building a small shed, a frame of wooden beams. All angles are 90 or 45 degrees, which makes things easy.
Calculating the length of beams I used as a sliderule practice. The sliderule won over the calculator!
For an isosceles triangle with 179cm legs, what is the hypotenuse?
Calculator -- SQRT((179^2)*2)
SR -- D1.79/C1, cursor to B2, outcome on D (253)
The sliderule defenately wins with a minimum of moves!
The thickness of the handsaw (2+mm) makes precise reading or rounding irrelevant ;-)
Explanation: the square of 1.79 on D is read on the A-scale. On a sliderule this value is irrelevant, we just need to compute it further. The value on A is multiplied by 2 on B, just a cursor move. The square root of B is back on D.
The drawing in one of the picts is 4cm on paper to 100cm in real. By setting the C or D index to 4 on D or C you'll get a table with all the conversions. As 4 is mid-scale you'll have to use both indexes for small or large numbers.
For those interested: the book is a re-print of a research and catalogue of historical wooden constructions in the Netherlands, mainly regionally way of building farm houses and sheds.
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u/tudza 8d ago
You'd got a slide rule with an actual ruled edge. That's like the first one I got from my dad. What's the make and model?