## Introduction: Cardboard Ball

Are you a geometry fanatic? Do you love soccer? Or, just got a lot of cardboard, and a shortage of balls? This Truncated Icosahedron model is a simple, and fun solution to making a cardboard ball. Just make a few stencils, copy the pattern below onto a sheet of cardboard, cut it out, fold it up, and finally glue it together. It holds together really well, and can be made in any size for whatever application. Go card-crazy with it!

## Step 1: Materials:

1. Cardboard

2. Scissors/Razor

3. Glue Gun

4. Pencil

5. Straight Edge

6. Printed Pattern/Stencil

## Step 2: Recycle Box:

Get out a box that is larger than the desired cut out size. Cut one face of it out, and set it on a hard surface in which it can be easily manipulated. Save the rest of the box for another project.

## Step 3: Cut Out Patterns:

Print out the documents linked at the bottom, and cut out the shapes. You can resize them by using the measuring tool. The key is to get the side length of the pentagon slightly smaller than that of the hexagon. The larger pattern is meant to be used as a reference tool, not a stencil, but you can transcribe that straight onto the cardboard if you can print it out large enough.

## Step 4: Transcribe the Pattern Onto the Sheet of Cardboard:

This is pretty straight forward, but time consuming. Use the reference pattern to find the correct location of each shape. Start in the middle of the cardboard, with the middle pentagon, then move out each layer. Make sure the lines are crisp. Use the straight edge to turn the rough outlines into a respectable shape. It is also important for the shapes to be lined up uniformly.

## Step 5: Cut/Score the Pattern:

Once you are done transferring the pattern, first, score the lines connecting the shapes, next, cut out the outer edges. Try to make a minimal amount of marks on the side that you score, as it will be the outer side of the truncated icosahedron. Take your time... watch a movie, listen to a podcast. Whatever allows you to focus.

## Step 6: Fold/Glue:

Once cut out, begin to coax the cardboard into position as shown above. The outer edge of each strand is meant to be glued to the inner edge of another. Apply hot glue to one side, and hold the edges together in the correct orientation. Let dry 30 seconds. The more connections glued, the stronger the ball. Trim as you go as to not have any unsightly gaps. As you get to the end, glue multiple edges together at the same time. Use your straight edge to plane off the excess glue. Good luck!

Participated in the
Cardboard Contest 2016