A spud gun or a potato launcher, as it is popularly known, is an interesting contraption to build. It is basically a device that lets you launch harmless projectiles to great distances. People enjoy making one, and shooting potatoes over long distances, just for the fun of it.
If you build and fire one around, make sure that you do so in an open space, where nobody is harmed by the vegetable projectiles. Also, make sure that you inform local police authorities about its use and clear out the issue with them.
Normally, there shouldn't be a problem, but since launching this projectile involves explosive combustion, it is good to be on the safer side, by informing the authorities. Unlike tasers or stun guns, these guns are made purely for the fun of launching potato projectiles.
Every device that is built, harnesses a physical principle. The principle behind building a spud gun is same as the principle of building cannons of ancient times.
The explosive expansion of a gas in a closed chamber creates a force, which launches the potato projectile, out of the chamber, to a distance which is directly proportional to the magnitude of explosive force.
Needless to say, the explosive nature of the firing mechanism, makes such a gun, dangerous to handle. One needs to ensure that its combustion chamber is strong enough to contain the explosion.
Besides that, you need to choose a liquid explosive, that is just right for this kind of a job and is sprayed in the right quantity. It should be powerful enough to launch the potato, without breaking the launching mechanism.
How to Build One
To make a spud gun, you will requires some raw materials. What you will need is PVC pipes, PVC adhesive, aerosol deodorant or silicone sprays, gas grill ignition device, a bagful of potatoes, and if you are a kid, an adult who can supervise you. Use eye protective gear and earmuffs when making the gun and later using it.
>>Firstly, obtain a good design for the gun. There are many available online. Study the designs and improve them with safety measures put in. A basic design consists of two parts primarily.
>>These include the combustion chamber and the barrel. The combustion chamber has an ignition device, attached to it, that triggers the firing explosion inside.
>>The barrel directs the projectile in right direction, while the chamber supplies the firepower. You can include a handle below the barrel or midway between the barrel and the chamber. Search online for good designs and improvise them to make your own. Put safety above everything else.
>>Cut the PVC pipes, according to the design and glue them together accordingly. One end of the gun should be sealed, on the side which houses the chamber and it should be only open on the barrel side.
>>To access the chamber and spray in the aerosol fuel for ignition, it is a good idea to have a cap on the barrel end, which can be removed when necessary. A hole needs to be drilled in the chamber, for fixing the ignition device. A gas grill ignition device will serve the purpose. Next, you must sharpen the barrel edge, with a file.
Once all the mentioned things are fixed in place, your gun should be ready. To fire the gun, push a potato inside the barrel and poke it in, as much a possible. Wear your eye protective gear and ear muffs. Make sure that you are in an open space and nobody gets hurt from the projectile.
Open the cap behind the chamber and spray an adequate quantity of aerosol. Then, close the chamber cap and ignite the gun, by hitting the trigger, after pointing it in the right direction. As you can see, there is risk involved and, therefore, don't attempt to make one, until you have thoroughly researched a safe design.