Film
Can ProjectilesLet's face it. Making things fly across the room is fun in any kid's book. The "flashy" demonstration we did in the spot on TV was found at a site called "Science Toys you can Make with your Kids". They call it the film can cannon. They even have a kit you can buy that looks more like a cannon than a block of wood.
You can get to the page with directions for the model we used on TV by clicking here.
How it works.
The ignitor is taken from a charcoal starter. It is made out of a material that is called a piezoelectric material, it changes its electrical properties based on its shape. When you push down on the button, the material is changes slightly and that is used to create a spark. In our case we use wires to have that spark occur inside the film can.
We also need a fuel to make this reaction go. There are different things you could use. We used Binaca, because it contains a relatively high concentration of alcohol which is a good fuel. Hair spray is another good fuel. It is NOT a good idea to use something like gasoline as your fuel as gasoline is much more dangerous (because it has a lower flash point).
The film can leaves with a considerable velocity and will generally hit the ceiling, even in a room with 20 foot ceilings. If you do make this toy, be sure to be aware of the surroundings - particularly the ceiling - before you set it off. Of course you don't want to aim it at anybody either. This is not an activity for unsupervised children.