Angles with just a Ruler

[glenfolly]

I've just revised this simple technique for creating angles using just a ruler and a scientific calculator(borrowed my sons Casio FX82).

It uses a little High School Trig that any 15yr old should be able to help with if needed.
Decided to re-post it using a couple of photos.



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This technique works really well for very small angles but will do any angle up to 90 degrees.
The idea is to make up some jigs of specific angles and then get on with making some sawdust
Alec

[Sydney]

I highly recommend this:


It is jammed packed with all sorts of reference tables, specs, conversion charts, and formulas.
Including All those Geometry and Trig. equations:
( you know - the ones in school you thought you would NEVER need to use. )
* I have also use Trig to layout compound angles ( especially those greater than 45 degrees )

[Jeff Beaird]

Help is just a phone call away... if your sister is like mine and has a Masters degree in Mathematics and currently serves in the School system.
Wow..? never thought the day would come that I would brag about my big Sis.

[DJ Big Ronn]

Help is just a phone call away... if your sister is like mine and has a Masters degree in Mathematics and currently serves in the School system.
Wow..? never thought the day would come that I would brag about my big Sis.

Tell me about it. My daughter is a Mechanical eng. grad from LSU, and she never let's me live down any math question that she answers for me. I knew that I shouldn't have been so mean to her.

[SoundInMotionDJ]

I highly recommend this:

And also this:
http://www.amazon.com/Engineering-Formu ... 0071457747

This book is very handy for all those calculus volume and area formulas that I forgot about sometimes in the last decade or so. There are sections on formulas for Electrical Engineering, Heat, Statistics, and a lot more.

As was pointed out, a 3 degree angle, in 10 inches of run, will produce just over about 0.5 inches of rise. For any woodworking that involves PL, that's more than close enough. (To ten-thousandths of an inch, the amount of rise in 10 inches of run is 0.5241. The 24 thousands worth of rounding error is more accuracy than any of these designs need.)

A 4 degree angle, in 10 inches of run, will produce just over about 0.7 inches of rise. For any woodworking that involves PL, that's more than close enough. In this case 3/4" of an inch is probably not close enough. (Again, to ten-thousandths of an inch, the amount of rise in 10 inches of run is 0.6992.)

--Stan Graves

[Harley]

The question begs!



Did the fly die from boredom - OR - should the title really be "Different angles on what can be done with a ruler"