This Instructable will teach you to make a basic, easily modded air cannon. The single-barreled version shoots 'ACRAZY far.

USE EXTREME CAUTION WITH THE PVC CEMENT AND EPOXY

Step 1: Gather the Parts

The following is a list of required parts:

If you want a double-barrel, include these parts in addition to the other parts:

1' of 1" diameter, threaded PVC pipe
3 1 1/2 long, 1" diameter threaded PVC pipe
2 quantity: 90 degree elbow joints (1" diameter)
1" diameter 3 way T-shaped pipe

If you want a single-barreled version, only use these parts
1' of 1" diameter, threaded PVC pipe
1 1/2 long 1" diameter threaded PVC pipe
1" diameter metal ball valve
1 or 2 ft. (The longer this pipe is, the more powerful the gun, but this is also for you to choose) of 2" diameter, (non-threaded) PVC pipe
Bicycle tire, any size
2" to 1" PVC reducer, non-threaded to threaded
2" PVC connector (used to join two 2" diam. pipes, ask an employee at a hardware store)
2" diameter PVC endcap

Now for the hardware

Epoxy, preferably flexible
Bike Pump
PVC primer
PVC cement
Scissors
Clamp (optional)

Step 2: Assembly (Part 1)

For the first step, simply assemble the barrel and ball valve as shown.
Now bask in the sunlight of your momentous accomplishment as you enjoy this dancing Kirby.
<(^.^<)<(^.^)>(>^.^)>

Step 3: Loading Mechanism

The loading mechanism is simply the valve of the bicycle tire put in the endcap.

1) cut the bicycle valve out of the tire (you can use scissors to do so)
2) drill a hole slightly larger than the valve into the middle of the endcap.
3) join the valve and the inner using the epoxy.

Note: DO NOT join the endcap with the shown pipe yet, if something goes wrong, you will need to restart.

Step 4: Assembly (Part 2)

Step 5: El Assembly Finale

For this step, you join the assembled endcap with the main structure using PVC primer and PVC cement.

Let dry overnight for maximum strength.

Step 6: THE END

For priming the cannon, you pump air into the valve from the bike tire using a bike pump as shown. About 20 pumps is enough. To shoot, load ammo (like a wet paper towel or a potato) into the barrels. They should fit tightly. Then pull the ball valve into an "open" position.

The End