Fibonacci Gauge

Very interesting device. Looks like a pretty simple tool to make, and worth the effort. I've got scrap strips cut out of 3/4" hardwoods in either 1/2" or 1/16" thicknesses. (Cutting board leftovers.) I've even got some flat portfolio screws that should work for the pivot points. Looks like pretty simple geometry to figure out the rest. Once you had the three points laid out, the rest could pretty much be done by eye. (That's my kind of woodworking...measuring is so overrated.) :rofl:
 
Neat Gauge

That is a slick gauge, but you weren't told why it was named Fibonacci gauge.

Leonardo Fibonacci was an Italian mathematician born in 1175 AD. In a book he published in the early 13th century, he defined the Fibonacci number sequence. The sequence is formed by adding together the previous two numbers in the sequence to obtain the next number. 0 1 1 2 3 5 8 13 21 34 55 89 144 etc.

How does the relate to the Greek 'golden ratio'? As it turns out, if you take any number in the Fibonacci sequence and divide it by the number previous to it, you will get an approximation of the 'golden ratio'. The larger the selected number the closer the division comes to the 'golden ratio'.

In the above sequence, if you divide 3 by 2, you get 1.5, but if you divide 21 by 13 you get 1.615. Going further up the sequence, 144/89 = 1.6179. Since the sequence is infinite, we can assume that the golden ratio is also infinitely long. As it turns out, the golden ratio is defined as (1+ sqrt(5))/2. The sqrt of 5 is a number that is also infinitely long, hence the golden ratio is also infinitely long.

Things like this lead one to think that the Great Architect of the Universe is a mathematician.
 
Last edited:
That is a slick gauge, but you weren't told why it was named Fibonacci gauge.

Leonardo Fibonacci was an Italian mathematician born in 1175 AD. In a book he published in the early 13th century, he defined the Fibonacci number sequence. The sequence is formed by adding together the previous two numbers in the sequence to obtain the next number. 0 1 1 2 3 5 8 13 21 34 55 89 144 etc.

How does the relate to the Greek 'golden ratio'? As it turns out, if you take any number in the Fibonacci sequence and divide it by the number previous to it, you will get an approximation of the 'golden ratio'. The larger the selected number the closer the division comes to the 'golden ratio'.

In the above sequence, if you divide 3 by 2, you get 1.5, but if you divide 21 by 13 you get 1.615. Going further up the sequence, 144/89 = 1.6179. Since the sequence is infinite, we can assume that the golden ratio is also infinitely long. As it turns out, the golden ratio is defined as (1+ sqrt(5))/2. The sqrt of 5 is a number that is also infinitely long, hence the golden ratio is also infinitely long.

Things like this lead to think that the Great Architect of the Universe is a mathematician.

There are some things in life we just don't need to know. :bang: ;)
He was ITALIAN, that's all that is important. :thumb:
 
This is one which a friend made for me.

fg_0001a.jpg


They do work well to check out proportions quickly, layout spaces say for drawers/doors.

Take care, Mike
 
Hi Frank--nope, they are brass. I just did a losy job of taking a picture. Too much light. In fact, the wood is nicely figured, a detail which is also lost in my picture.

fg_0002a.jpg


Shows the brass color a bit better--but still not the wood's figure. One day if I find the energy perhaps I'll take another picture...

Take care, Mike
 
So Mike, any chance your friend wants to make a bunch of those nice tools and sell them to us commoners?

That is once nice looking tool! It should go well with your saws!
 
So Mike, any chance your friend wants to make a bunch of those nice tools and sell them to us commoners?

That is once nice looking tool! It should go well with your saws!
I'm thinking of trying to make one or two of them. I've got a little bit of scrap brass that I've been saving for 25 or 30 years that could be made into points...I'm trying to figure out how to attach the brass tips to the wood. :huh: I'm guessing thin steel pins and epoxy?
 
Very nice guage Frank, thanks for posting it. I think I will make one. Just the other day I was talking to a friend about Phi and telling him furniture makers use this proportion often.
 
So Mike, any chance your friend wants to make a bunch of those nice tools and sell them to us commoners?

That is once nice looking tool! It should go well with your saws!
Hi Martin,

I doubt the person would make a bunch of them, but you never know. This one was made by Derek Cohen and so the wood is an Aussie wood. Good stuff.

Good thing the plans are readily available! It is an afternoon's project.

Vaughn, the most common way to attach the brass is with epoxy and pins like a bevel gauge is done.

I doubt we would ever add the gauge to our planned list of tools to provide in the future. It would be kinda like us making simple marking gauges--no one would be willing to pay what we would need to charge.

Take care, Mike
 
This is a very interesting project. I saw the orginial write up in the mag. and have always been impressed with the golden proportions and Fabonacci.
The Fabonacci sequence is used to layout the volute found at the bottom of many staircases.
I think I may build a gage myself. Thanks for the post Frank.

Richard
 
Top