Catenary Bowls?

[Neil Strong]

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I have what I think are some examples, but it's a fine distinction between some true parabolic and some catenary curves...

Catenary-Parabolic.jpg

And, of course, the catenary comes in many variations, depending on the suspension length (sag) and distance between suspension points.

Catenary with various values.png

Also, the piece has to be photographed square to its side (something I rarely do), for the true curve to be seen. Anyway, here are a few that I think are close to catenary. In some cases you have to mentally complete the curve into the foot...

Native pine 6in.JPG

Native cherry 5.5in.jpg

And with others you have mentally separate the curve at the bottom of the piece at which point it transitions into the upper part of the piece...

Birch - 11 x 9.25in.jpg

Holly & BW 11 x 6in.jpg

[Neil Strong]

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And with others you have mentally separate the curve at the bottom of the piece at which point it transitions into the upper part of the piece...

I do have a few pieces where I've made an abrupt change from the catenary shape in the bottom of the piece into a closing form on the top of the piece, in which case the bottom catenary is more obvious...

Walnut 9in w x 6in h.jpg

IMG_1196.jpg

Blackwood - 6.5 x 3in.jpg

The flutes on many makes of bowl gouges are now described as parabolic, some of them erroneously so where they have a distinct V flute profile with straight sides. But, of those that are more genuinely described as parabolic, there are some that could be more accurately described as catenary. However, it is hard enough getting only those BGs with true parabolic flute profiles to be called that without adding another flute descriptor into the terminology we use to describe flute profiles.

For those with a geometry bent, the following is a link that explains how a catenary would have almost the the same curve as a parabola (given the same span and sag) if the catenary was formed by a cable/chain carrying no weight other than itself.

https://en.wikipedia.org/wiki/File:C...y_parabola.svg