Woodworker Keith Williams shared a remarkable timelapse showing how he transforms flat plywood boards into beautiful geodesic spheres of different sizes. The large sphere is made of 180 triangles which are made into 12 pentagons and 20 hexagons, while the smaller sphere that rolls by at the end are made up of 60 triangles that form 12 pentagons.
While the math seems complicated, Williams states that he prefers the “caveman method” of measuring.
I’m not a math genius. The trig. involved in a lot of this is way too advanced for me. Here is my “caveman” method for figuring bevel angles. One easy way to figure the angles for any given polyhedron layout is to make a model out of 1/8” tempered hardboard. Hot melt glue it together edge to edge. The glue will allow some flex, and you don’t need a bevel angle. Use a digital protractor (not an exotic tool anymore) to measure the outside angle and then bisect it for the bevel angle. This will get you close.
Williams explains the difference between the two sizes and builds the smaller sphere in a separate video.
via The Awesomer