Awesome Cheap Pneumatic Cannon!

In this instructable, I will be showing you how to make a cheap and powerful air cannon. It's one of the most simple pneumatic "air cannons" It's power, cheap, simple to build and will launch a potato or other projectile a very long distance. This is my first cannon build but I do have experience with PVC and launchers (See my water bottle rocket launcher here)

Let's get started!

And be sure to check out lewster's page. He made the first cannon and inspired me to build this one, because I couldn't use his with my air compressor. Thanks L

Here are the parts you will need:
Some sort of valve (I used a 25mm [1"] ball valve)
2x 50cm lengths of Pressure rated PVC pipe (same as your valve size. In my case, 25mm)
End cap to suit your PVC pipe (again, 25mm)
Barb to 1/4" air fitting (I placed it in my end cap with epoxy)
Schrader valve
2x hose clamps
30cm (1 foot) of air compressor tube

Tools your will need:
Hacksaw
PVC cement
Something to get rid of burs

That is all you will need!

Now you need to put everything together. Before you put everything together with glue, just make sure everything fits together before you glue it. Put it together like picture one. Simple!

Now glue everything with PVC cement and primer. Follow the instructions on the label and glue everything together.
Give 24 hours for the glue to fully cure before applying pressure

Follow the pictures and assemble the system. Make sure the hose clamps are good and tight.

You might want to spray paint the cannon or something but now you have a simple, working cannon!

This is a potentially lethal project if misused. Never shoot or point this cannon at any living thing or things that are not targets. Handle the primed cannon with extreme care. Test the cannon remotely if possible on first test. Keep doing that for about five shots. Do not fire explosive. This cannon can potentially hurt you or surrounding people. Do exercise extreme caution at all times. 
That is all I have to say

Simple. Attach air compressor or bike pump to the schrader valve and fill to 60psi. Put desired ammo down the barrel and open the valve to fire.

Improvements:
My first major improvement was having inter-changeable barrels. To do this, get a male and female pair of 1" threaded to glue-on couplings. Cut the barrel about 1" from the valve and glue in the PVC couplings. To add another barrel, get a male coupling and glue it, with the suitable step down, or step up, coupling to suit the barrel size. I have a 15mm, 1m barrel and it's very accurate. I soldered up a cross-sight for aiming and it's fun to use. I also ordered a laser and it's going to attach to the barrel so I don't have to look through the sight. The next upgrade would be to upgrade the air chamber to a bigger diameter pipe.

Have fun with your new cannon!