Credits out of the way, geodesic domes are beautiful structures. Spheres give the greatest interior volume with the minimum of material. Their basic geometry can be broken up into hexagons and pentagons, or further broken up into triangles. See the rotating geogedisic spheres on the Buckminster Fuller page.

This model is made up of triangle units, which I then combined into hexagons and pentagons. Those units were then combined to make the sphere. I used bamboo shish-kabob skewers from the supermarket (called pincho sticks where I live), and hot melt glue.

**Signing Up**

## Step 1: GEOMETRY

In a flat pentagon (5 sides) the two sides of the triangles that radiate from the center will be shorter than the third side. To more closely approximate a sphere, you have to lengthen them also. As with the hexagon, the amount that those sides are lengthened will determine the height of the peak in the center.

I don't know the math for making triangles that result in a near-perfect sphere, but I find the idea of lumpy domes and peaky geodesic spheres more interesting anyway. Just playing it by feel, this is the design I came up with.

I used the same triangles for making the hexagons and the pentagons. The dimensions I used for the triangles are: 2 inches for the short side, 2 1/4 inches for the long sides. Whatever variations you do with sides that radiate from the center, the outer sides have to be the same so that the hexagons and pentagons will join correctly.

(I have plans for making a next-generation model with the hexagon peaks going inward and the pentagon peaks going outward, to make a pollen grain-like structure.)

## Step 2: TOOLS AND MATERIALS

Hot melt glue gun

Materials: Flat working surface

Non-stick work surface cover (Teflon cloth)

Vinyl (or cardboard) to make a holding jig for the sticks while gluing them

Bamboo shis-kebab ("pincho") sticks from the supermarket.

Hot melt glue

## Step 3: CUT STICKS TO LENGTH

Unless you are really enamored by the way mine turned out using 2 inch and 2 1/4 inch pieces, have fun and create your own variations.

When I decided on the dimensions I was going to use, I cut a sample stick of the two sizes and used those sticks as guides for cutting all the other sticks of the same length. That way, all I had to do was match up stick ends, butt the cutters up against the other end of the guide stick and snip.

If you use different lengths for the radiating triangle sides of the hexagons and pentagons, you will have to cut three different lengths, not two.

## Step 4: MAKE A HOLDING JIG

Over the Teflon cloth, I stapled down some vinyl material as guides to hold the bamboo stick sections. You could probably use cardboard, or maybe ice cream sticks. Leave the corner areas open, since that is where you will be using the glue and you don't want to gum up your holding jig.

Once I got the sticks positioned in the jig, I set a weight on them to hold them in place. (I used a big round washer with some magnets stuck to it as the weight.) The sticks are so light that any pressure from the glue gun can dislodge them if they are not held in place.

## Step 5: ASSEMBLE THE HEXAGON AND PENTAGON UNITS

Putting in the last triangle of each unit is the trickiest part, since you have to fold the assembled polygons some as you raise the center peak. Fortunately, the hot melt glue is flexible, so joints hinge nicely. The glue also cools and solidifies quickly, so you can hold it by hand until the last glue job hardens up. As you hold it, keep the base of the hexagon or pentagon unit pressed against the flat base of the work surface so that the base of the hexagon or pentagon will be in a flat plane.

I'm making this exactly how you are, with 2 in pieces and 2 and 1/4 in pieces, but how do I know how pieces of each measurement to cut?

Each raised pentagon uses 10 of the long pieces and five of the short pieces.

Count the hexagons and pentagons you need to know the number of pieces you need of each kind. After you have all the raised hexagons and pentagons put together, assemble them into the sphere.

Do you think you could help?

https://en.wikipedia.org/wiki/File:G%C3%A9ode_V_3_1.gif

Thanks

I'm just a little bit before step 6.

I did the first pentagon, 5 hex, and 5 pent.

Next layer will be 5 hex. Actually it stands at 12inch high.

I used popsicle stick I found in my old appartment. not sure I'll have enough though..

Added a Row tonight using all that was left of stick.

Then went to buy all the stick I will need to finish it. Plus all the glue...

Want to build one the size of a mouse or the size of a house heres the place you need

I been playing with these for a long time...

If you want the corners to be more precise, try marking the end cuts with a pencil and then whacking it with a sharp chisel and a hammer over a block of wood to make the cut. It should be fairly fast and precise.

You could calculate the angles with math or come close enough with trial and error. When you have your pattern stick you can easily cut copies of it.

Just a thought i wouldn't go much hight than a 60 watt bulb with a paper cover anyway .....

I made a similar structure a few years back (en.wikipedia.org/wiki/Small_ditrigonal_icosidodecahedron) with hot glue and toothpicks -- and covered it with tissue paper.

I hung it up as a lampshade (on an incandescent bulb) and within a few hours it had fallen down to the ground misshapen and somewhat concave... :(

Very nice 'ible!

Because you can model almost anything with small enough triangles (as in, for computer graphics) you can make non-regular shapes (like faces, etc.) too. I am however, quite partial to the regular sphere-like shapes.