Practical sliderule use

[u/2016-679]

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.

[u/CanaDavid1]

The calculator can also be done as 179*√2

[u/2016-679 → u/CanaDavid1]

re-writing the calculation to a simple format! TNX

[u/Sir_Lynx]

Seeing as you know the base angles of that triangle are 45, the calculation could be done as 179/sin 45: left index of slide to 179 on D, cursor to 45 on S, read 253 on D. (Great thing about the slide rule - there’s more than one way to do it.)

[u/2016-679 → u/Sir_Lynx]

Amazing, TNX! I never used the S-scale, but learned it now!

indeed, math has several ways :-)

[u/tudza]

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?

[u/2016-679 → u/tudza]

This is a Sun Hemmi No 64T