# How to make a geodesic dome's scale model with cardboard,

What we need:

Pen and paper, a calculator, a pencil, some rulers, a compass, a cutter knife, masking tape, glue, single or double wall corrugated cardboard, a work table and "patience".

Introduction.

Let say you wanna make a dummy of a dome that's 40 feet (40') in diameter and it's comprised of pentagons and hexagons, sort of like the same general layout in a typical soccer ball. Have a look at the 1st. picture. Although in this case, our soccer ball is cut in half (so to speak). That's why it's called a dome. Isn't it? We don't have 12 pentagons and 20 hexagons like in a soccer ball, but only 6 pentagons, 10 hexagons and 5 half hexagons.

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## Step 1:

Another difference is that we don't have just plain polygons. Pentagons and hexagons in our dome, are comprised in turn of a series of triangles; as we can see on our fully assembled dome in the picture.

## Step 2: Some technical data and measurements,

We have 105 isosceles triangles. Don't worry, we're not gonna make as many triangles and try to "patch" them together. That would take forever! So this is what we do:

The scale of our model is 1:48, which means, it's 48 times smaller than the real building would be. That's the same as saying that 1 foot (1') is equivalent to 1/4 of an inch (1/4"). This time we're gonna use centimeters (cm.) and millimeters (mm.). Since 1" equals 2.54 cm., a 1/4" equals 0.635 cm. So to make a long story short, in this project 1' is the same as 0.635 cm.

If we think of our dome as a structure, each edge (the line where the sides of two triangles meet) is equivalent to or represents a strut. We have in our dome three basic types of struts, A, B and C. Once we do the calculations and know the length of each strut, we'll be ready to rock & roll!
Very nice instructable, having built a Dalek as a complete mathematical dunce and having to figure out all the geometry for that I could really have done with this as a template several years ago! These are fascinating structures, a friend has a geodesic dome tent which he built himself using plastic piping and tubing and it's a lovely thing to sit inside.