## Introduction: Aluminium Decoder

This decoder is used for decoding and coding the caesar cipher.

http://en.wikipedia.org/wiki/Caesar_cipher

You could make two and give one to your friend so you can send secret messages to each other

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## Step 1: Materials

Soft drink can

pen

stanley knife

ruler

compass

a paper clip (I forgot to take a picture)

Scissors (optional)

## Step 2: Cut Up the Can

Use the stanley knife or scissors to take off both ends of the can. I prefer using the knife to the scissors.

## Step 3: Prepare the Can

Cut the cylinder to make a rectangle and flatten it by rolling it backwards

## Step 4: Draw & Cut Out the Parts

Radius of the small circle is 2 cm and radius of the big circle is 3 cm.

Cut them out with a stanley knife or scissors

## Step 5: The Maths-Outer Circle

## Step 6: The Maths-Inner Circle

This is how to work out how wide each letter should be

## Step 7: Draw the Spaces

Use the previous calculations to space each sector. Try to get them as accurate as possible.

Make another circle on the smaller circle with the pen with about a 1 cm radius.

## Step 8: Draw on the Letters

Draw on the spaces where the letters will go first

## Step 9: Put It Together

Put a paper clip through and bend the ends over it or you could put some hot glue on

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## Discussions

9 years ago on Step 4

you put three pictures there