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How to Build a Geodesic Dome Model
by Trevor Blake

This is a low-cost, easy to assemble model of one type of geodesic dome. Make the triangle panels described below with heavy paper or transparencies, then connect the panels with paper fasteners or glue.

Geodesic domes are usually hemispheres (parts of spheres, like half a ball) made up of triangles. The parts of a triangle are called the face (the part in the middle), the edge (the line between corners), and the vertex (where the edges meet). All triangles have two faces (one viewed from 'inside' the dome and one viewed from 'outside' the dome), three edges and three vertex. There can be many different lengths in edges and angles of vertex in a triangle. All 'flat' triangles have vertex that add up to 180 degrees. Triangles drawn on spheres or other shapes do not have vertex that add up to 180 degrees, but all the triangles in this model are 'flat.'

One kind of triangle is an equilateral triangle, which has three edges of identical length and three vertex of identical angle. There are no equilateral triangles in a geodesic dome, although the differences in the edges and vertex is not always immediately visible. This particular geodesic dome uses three different edge lengths and two types of triangles.

Edge Lengths:
A = .3486
B = .4035
C = .4124

The edge lengths listed above can be measured in any way you like (including inches or centemeters); what is important is to preserve their relationship. For example, if you make edge A 34.86 centemeters long, make edge B 40.35 centemeters long and edge C 41.24 centemeters long. This dome has a radius of one: that is, to make a dome where the distance from the center to the outside is equal to one (one meter, one mile, etc.) you will use panels that are divisions of one by these amounts. So if you know you want a dome with a diameter of one, you know you need an A strut that is one divided by .3486.

You can also make the triangles by their angles. Do you need to measure an AA angle that is exactly 60.708416 degrees? Not for this model: measuring to two decimal places should be enough. The full angle is provided here to show that the three vertex of the AAB panels and the three vertex of the CCB panels each add up to 180 degrees.

AA = 60.708416
AB = 58.583164
CC = 60.708416
CB = 58.583164

1. Make seventy five triangles with two C edges and one B edge. These will be called CCB panels, because they have two C edges and one B edge. Make thirty triangles with two A edges and one B edge. Include a foldable flap on each edge so you can join your triangles with paper fasteners or glue. These will be called AAB panels, because they have two A edges and one B edge. You now have 75 CCB panels and 30 AAB panels.

Now you can decorate it. How would it look if it were a house? How would it look if it were a factory? How would it look under the ocean or on the moon? Where would the doors go? Where would the windows go?

If you would like to make this dome with struts instead of panels, use the same length ratios to make 30 A struts, 55 B struts and 80 C struts.

The first geodesic dome was built by Dr. Walter Bauersfeld in 1922. Buckminster Fuller obtained his first patent for a geodesic dome in 1951 (patent number 2,682,235). Geodesic domes are a good way to make buildings. They are inexpensive, strong, easy to assemble and easy to tear down. They can even be built, picked up and moved somewhere else. Domes make good temporary emergency shelters as well as long-term buildings. Perhaps some day they will be used in outer space, on other planets or under the ocean. If geodesic domes were made like automobiles and airplanes are made, on assembly lines in large numbers, almost everyone in the world today could afford to have a home.

Copyright © 1998, 1999, 2000, 2001 Trevor Blake (box2321@box2321.com). All rights reserved. Permission granted to reproduce and distribute for non-profit and educational use.