Hi Everyone
This is my first instructable!

It's about a rotary saw made from a tin box that can cut cardboard. I made it because I had a broken tin lying around and wanted to experiment with it.

Please feel free to include critical reviews and advice in your comments!

Step 1: What You Need:

- A pair of pliers
- A compass and felt tip pen ( to draw the circle on the tin) - A tin cutter

- A piece of tin (to cut the blade from)
- A DC motor with bolts to attach the blade - A few pieces of thin wood board (to mount the motor on) - A power supply or 4 AA battery holder & batteries

Step 2: Making the Saw Blade

First cut a piece of tin a bit bigger than than you want your saw blade. ( Remember the bigger the blade, the more it will flex. )

Now press the point of your compass through the tin and draw a circle of any size with the pen.

Cut the bigger circle out with the tin cutter.

Now cut the teeth using the tin cutter using the inner circle as a guide.

Be careful not to cut yourself on the blade.

Now use your pliers to flatten the bent teeth.

Step 3: Mounting the Blade to the Motor

First enlarge the hole made by the compass with something sharp like a nail.

When the hole is big enough, screw it onto the motor.

Now fasten the blade using the nut. Make it tight, so the blade won't fly off the motor when you use it.

Step 4: Mounting the Motor

To mount the motor, drill holes for the motor screws and for the shaft in the vertical piece of wood. Now screw the vertical piece to a thicker horizontal base.

Step 5: Adding Power

You have two options for power: a battery pack or a power supply that plugs into a wall socket.

The battery pack option is portable but the batteries will quickly run out.

With a power supply you can give your motor more power. It would be a good idea to add a switch so you don't have to unplug the wires when you want to switch the saw on and off.