Compressed Air Cannon

This Instructable will guide you through the steps to build a basic air powered cannon to launch things such as water balloons or t-shirts. Measurements for the air tank and barrel lengths, found in steps 2 and 3, are the dimensions that we found to work well, but are meant only as guidelines. 

Notice: Please be safe when following this Instructable. Use tools safely; do not to over-pressurize the air tank and never aim or fire projectiles at anyone or anything. We are not responsible for any injury or damages you cause as a result of using or building this air cannon.

Step 1 Materials & Tools

Materials Needed:
5’ section of 3” PVC schedule 40 pipe----$5.93
1 3” PVC End Cap----$3.63
2 3”-1.5” PVC Reducers----$2.64 each
2 1.5” PVC-DWV Trap Adapter – Spigot Connection----$0.83
1 1.5” Ball Valve – Threaded----$9.71
1 Metal Tire Fill Valve (Bolt-in Type) ----$2.99

Materials You Might Have:
PVC Cleaner----$2.58
PVC Glue----$2.44
Teflon Tape (Seal Tape) ----$.058

Tools Needed:
Saw----$3.49
Drill----$14.99
Drill Bit to Fit Tire Fill Valve----$2.38
Tape Measure----$4.77
File----$3.17
Bicycle Pump or Air Compressor
Electrical Tape (optional)
Clamps (optional)

* Note: Prices listed were found at our local Menards and are listed to be used as an estimate only.

Comments

[ramicaza]

holy... please tell me you don't pressurize this to more than 10 psi lol. That cellular core is extremely dangerous along with you're dwv reducers but those are the least of your worries.

[igotair]

please, please, please, dont use foam core for applications that will be under pressure. never, never, never under ANY circumstances. Doing so is just asking for a visit to the emergency room. i know large diameters of schedule 40 labled for pressure are hard to find, but it is safer to use a smaller diameter pipe and use it in multiples than using foam core.

[iloveairsoftstuff]

uhhh... dude. please tell me that the pictures of the air chamber are a mistake and not what you actually used. cellcore pipe WILL explode and is a VERY bad idea. the cannon is a good one ACCEPT for that. please clarify in your instructable that cellcore pipe is not what is to be used. this is VERY dangerous.

[SeamusDubh]

while a ball valve gives you a greater pressure seal. it is better to use a butterfly valve. they open quicker with a higher initial flow bast the valve.