# Bob Rollings

My interest in geometry and math no doubt stems from a lifetime spent in the cabinet making industry. Initially, I worked as a hands-on craftsman and then later in a supervisory position. I spent my time interpreting designer/architectural concepts and turning them into practical and beautiful pieces. After my retirement in 1996 I turned my interest in geometry into a hobby. Using wood as a medium and a lath as one of my many tools, I started a second journey of discovery as a wood turner/artist.

I initially only intended to make the largest of this group but after its completion I decided to make a second vase only half the original size. The largest vase consists of 28 levels each having 24 pieces that are 1/2" thick for a total of 576 pieces.The second vase has the same 576 segments but are 1/4” thick creating a perfect copy at half the size. The second vase received so many positive comments that I was encouraged to continue onward and downward deciding to reduce the segments even further. The 3rd and 4th vases have thicknesses of 3/16" and 1/8" respectively. As I reduced the sizes of the vases it became obvious, that smaller proved to be more difficult.

The wood used in this piece is Indian Rosewood. What interested me in this particular closed form was the accuracy that would be required to cut sixty irregular pentagonal panels, ¼” thick, on the table saw. Four of the interior angles for each panel are 118.13 degrees with the other one being 67.46 degrees.

Given that the dihedral angle was 153 degrees, I could calculate all of the side angles to be 13.5 degrees.

Having all this information it only remained for me to prove that my calculations were correct by producing the pentagonal hexecontahedron.