A device similar to a potato cannon, in that it fires potatoes
large distances. It is far superior, and in this node I'll give
you a quick guide on how to build one.
The principle behind a pneumatic air cannon is pretty simple. You
have one tube of PVC pressure pipe that holds compressed air
(usually to the order of 100 PSI). It is separated from another
pipe by a valve. When the valve is opened, the air is released into
the second pipe, firing the projectile (usually a potato, but
other things can be used).
They are relatively cheap to make. Mine cost about NZ$60 (US$30),
but your mileage will vary widely depending on your location, and
your supplier. All parts are available at your local plumbing
supplies store, except for the tyre valve, which you should get at a
mag wheels store.
The cannon described here is a basic "artillery" style one. There
are many advances made on it, but this is the cheapest. I measured
the range of mine as 130 metres!
What you need
2 one metre lengths of 50mm PVC pressure pipe. This must be able to
sustain pressures of at least 125 psi, else it will explode!
Valve mechanism. This consists of a 25mm ball valve, and adapters
to connect it to the 2 pipes.
1 endcap. Again pressure pipe
Car tyre valve
Really good solvent.
A pump. Not a foot pump The best sort is a 'T'
type, that you push down on to operate. A bicycle pump probably
won't do the trick unless you're really strong. One's designed for
car tyres are best. Alternatively you could use an air compressor.
Drill a hole near the end of one of the pipes, and attach the valve,
so that air can be pumped into the pipe.
Glue the endcap on the end of this pipe. This is the pressure
Attach the adapters to the pressure chamber and the barrel (the other
50ml pipe). You'll have to work this our yourself as there are heaps
different possibilities as to how this works. Basically, you want
the valve to be in-between the two pipes.
Once the glue is set, it's ready! You are now ready to fire potatoes
and other vegetables large distances.
Get a potato of a size that it covers the entire end of the barrel.
Jam it down to the bottom of the barrel with a broomstick.
Pump up the pressure chamber as much as you can.
Open the valve. You should hear a thoomp sound, followed by the
scream of an innocent bystander you hadn't seen.
Getting the Most from Your Cannon
Now that you have your cannon, it's time to tweak it. The design you
have is very basic, and there are many advances on it you can make.
Firstly, sharpen the barrel. This makes the potatoes cut better,
producing a better seal.
Check all your joins. If there are any leaks, fix them with glue.
If they are threaded joins, get some plumbing tape to seal them.
One of the most common things I've seen on the internet is to use a
solenoid sprinkler valve instead of a ball valve. This opens
much faster, and is electrically operated so you have a trigger.
Keep in mind this will double the cost of your cannon.
Make the pressure chamber sit under the barrel. You can achieve this
by attaching some elbow joins around the valve. This combined with
a solenoid valve means you can carry it around like a gun!
You can look around for more information on different designs. The
internet is rife with information, as there are many cannon
fanatics out there.
After a couple of weeks, you'll find that potatoes don't offer the
same entertainment that they used to. Now it is time to use
When looking to created more destruction, ice is your friend. A
frozen orange will cause massive damage at high speed. Get a small
portion of 50 ml pipe, and stick and orange or other food product in
there. Freeze it over night. It will fit in your cannon, and go
While on the subject of ice, frozen water balloons are wicked as
well. Lube it up, as the rubber will create a lot of friction.
Water (in liquid form). This is fun, half fill your barrel up and
it will vaporise the water, giving you a refreshing mist on a hot
Confetti. Stick some confetti in there and shower your neighbourhood
OK guys be sensible. These things are pretty safe, provided
no one is in front of the barrel . I'm not exaggerating,
this could kill someone if fired at close range.
Don't do what I did and do you're first test fire straight up in the
air. It comes back down and it comes back down fast.
Keep it out of reach of irresponsible morons. The only exception
to this rule is if the moron in question is you.
Oh yea, and these are illegal in lots of places, so don't get
caught with it by a police officer. If they don’t know what it is
they may mistake it for a really weird bong.
Have fun and don't damage/maim/hurt any thing I wouldn't