My Phi experiment

[Kevin McPeek]

A few of us have touched on phi (the golden ratio) a few times here and there. In doing research I found a web page that showed how to make a phi gauge...so I did.
I took a blank that I would get about a 4" diameter out of and went from there. Now some (all) of my choices were arbitrarily chosen as to what portion of phi I used. I used a phi calculator to come up with the following dimensions. http://www.calculator.com/calcs/calc_golden.html
Anyway, using 4" diameter I calculated that I should have a height of 6.472". Using that I deducted that the largest diameter should be 2.472" from the top or bottom, I chose top. Then using the diameter I found that the top or bottom should be 2.472, I chose top, and the other end should be 1.527, which is where I intended the bottom to be. A "design opportunity" left me having a bottom around 1 1/4".
Somewhere along the way I buggered up the form, and I left the bottom a little too heavy, I was worried about it falling over but I over compensated for it.
Anyway, heres what I ended up with. The blank has a crack in it so its staying home anyway, so I'm not all that broken up about it.

[Kevin McPeek]

And here is the gauge.
Here is where I found it. http://goldennumber.net/goldgrid.htm

Edit: Sorry wrong link

[maico tercero]

where can I buy the gouge of the photo?

[Kevin McPeek]

I made that one, but they have one for sale also
http://goldennumber.net/gauges.htm

[Mike Vickery]

Interesting experiment.

I have to say while it has a pleasant curve and nice workmanship the proportions look off to me. The widest part of the piece seems like it should be higher to me and the rim looks a touch to wide.

Just my 2 cents, but hey this is why play. I am curious what others think because the idea sounds like it has real merit.

[Kevin McPeek]

Yeah, I'm chalking this up to a learning experience. Way too many calculation went into this for turning though. On a side note the gauge works pretty well. When I put it on paper first the form looked better, but I had no plans for the opening at that point. So it was kind of second thought, it is undercut about 1/4".

[charlie knighton]

your form is excellant, if your gauge helped good

[joe greiner]

I made one from 1/4" plywood, using binding posts for the hinges - 3/16" barrel IIRC. Cost a whole lot less than $100. And no shipping charges.

2.236 is sqrt(5);
3.23607 is that plus 1;
1.61803 is half that;
0.61803 is inverse thereof;
0.38197 is square of that.

b = a * 0.618;
c = a * 0.38197.

Joe

[Kevin McPeek]

Here is the one I used, mine is made of aluminum (but I had a waterjet to make it on)-
http://goldennumber.net/images/goldensectiongauge.gif