Aug 2013 Demo

“Classic Curves in Bowl Design”

By John Beasley

The literature on bowl design discusses the classic curves – sphere, catenary, and ellipse, proportion based on the Golden Mean, and considerations for proper foot design leading to the conclusion that if you turn to these parameters it will be an appealing bowl. Then, ironically, you don’t find pictures showing the results. Therefore I decided to find out for myself.

 The demonstration will cover how to draw each of the curves and make templates for turning including the foot to proportion. We will look at 21 bowls where the height is held constant and the diameter varied over a range to compare the curves and introduce the concept of an aspect ratio to identify differences and similarities of each curve over the range of diameters. Then we will look at another dozen or so bowls where we increase both the height and diameter.

 Let’s have some fun and a lot of interaction to see what we can conclude from this work that they don’t tell us in the design literature.