Everyone enjoys a good explosion or long distance launch.  Learn to build your own canon project uses a simple ingredient – dry ice (frozen carbon dioxide) which goes directly from solid to gas. The process called sublimation releases a lot of the built up pressure.  Consider this…1 pound of dry ice turns to gas and gives you 250 liters of gas! That’s a lot of gas and a lot of latent propellant. The water fast tracks the form change of the dry ice creating an explosive propellant.

It’s essential to pay attention to the build of the canon itself with all that charged up gas. Over pressurization is a hazard. Note the careful mechanism of the canon in the video. The canon is entirely made up of steel and tightly welded together. A PET bottle is connected to the explosion chamber using a CNC adapter. Dry ice is poured into the PET bottle and water is injected through another bottle to trigger the process. The escaping gas launches a front loaded projectile through the barrel.

The added exhaust valve acts as a pressure release valve and is the first safety feature. The second one is a pressure gauge which monitors the critical pressure when the PET bottle explodes.  The range according to the makers is around 80 meters. The cost? $200.  The shoulder fired bazooka uses a simple chemistry principle. Fun, but serious so always use safety precautions.

Here’s more ammunition for your thoughts in our gallery of Airsoft and Gun projects.

• Head Mounted Water Canon = Summer Fun
• Incredible Gas Powered Vortex Canon
• Pirate Cannon – Pneumatic Style

A water canon is a great way to have fun and remain cool under the collar. The head mounted water canon is the latest weapon of wet destruction in town. It is not your average plastic squirter glued on to your helmet – it’s a combo of a pressurized stainless steel fire extinguisher and a motorcycle helmet.

It’s a fire on sight system – look and shoot a jet of water. The helmet with visor serves as protection against retaliatory attacks. The ammo is five gallons of icy cold water at 100psi. Water extinguishers are not used anymore so you probably will be able to scrounge yourself one. Though any helmet will do, we guess you would want to fuss over the look. A few other materials like a bicycle brake lever unit, diver’s backplate, vinyl tubing and a few components go into the assembly.

Its creator, John Young calls it The Ultimate Water Gun. Check out the photo stream and the video above. The detailed instructions show that the end result is not a child’s toy but a serious fun shooter. Make yourself one and go look for a fight. Scoot over to our gallery of Airsoft and Gun projects and take aim at building some custom firepower.

Learn to build your own Aperture Science handheld Portal Gun just like one in the game. Construction is fairly simple, requiring basic carpentry and molding skills.  All it needs now is a few LEDs and lasers to make it even better. A few basic materials for this project include:

• Wood filler (this stuff is vital!)
• Exercise mat foam
• Folder plastic
• 5 Liter paint can
• Chicken Wire

Don’t miss out on this DIY Portal Case Mod: