A Geodesic Sphere

A Straw Ball

At one point, at the end of a semester, I allowed myself a day or two of MY kind of fun. I decided to build a small geodesic sphere.

With a pack of drinking straws, a hot melt glue gun and a little geometry, I set out to do this.

At first I was surprised at, as usual, my shattered misguided preconceptions. To me, it always looked like any geodesic surface was made up of equal triangles. As I set out, I realized, there are actually a subset of shapes, pentagons and hexagons, which then get filled up, and the whole sphere appears to be made of similar triangles, to the casual observer, me.

Getting the angles.

To figure out the height, I resorted to a bit of trigonometry and geometry. I made a very crude jig out of plywood and finish nails, once the side lengths of the pentagon and hexagons were determined. The finish nails held the ends of the straws up the proper distance so that the center point of them would be also incident with the sphere being described.

There isn't alot more to say about this except, later I saw many physics and math gadgets that make cool shapes and cost quite a bit, but it was really alot of fun to make this cool shape with inexpensive items and solve the problems innovatively.

Please be forewarned, hot melt glue is hot. After hours of sticking straws together, you most likely will get a burn or two. Be careful, if the glue it too hot, it just melts the straw, too.