Hi there! This air cannon is a great project for anyone. It's easy to make, fun to play with, and not to eat. This is the first air cannon I ever built, but the most recent one I have finished. What? Let me explain. I started this project 3 to 4 years ago. This was a time were I really didn't know what I was doing. I bought a bunch of parts, put it together, and it didn't work. My previous design was seriously flawed and I never got the cannon working.

Since then I have made many air cannons and have a better understanding of them. Two days ago I saw the old, worn-down air cannon in the corner of my workshop. I decided to do something I should have done a long time ago. The design is now simpler and better!

!Warning!(I usually make my initial warning funny, but I'm feeling lazy) This cannon, if used incorrectly could kill you in multiple ways. It is made of PVC and if to much pressure is applied your cannon could explode, injuring you horribly. You should never pump your cannon more that 60 PSI. Also, this is a CANNON. It shoots stuff hard and fast. If you shoot yourself our someone else with it, you will get hurt. I'm not responsible for any damage you cause to property, yourself, or others.

With that out of the way, let's begin!

Step 1: Materials and Tools

Every thing you need to make this cannon can be purchased at your local hardware store, except for the tubeless tire valve.

PVC parts
1- 1 1/4" PVC Ball Valve
1- 5' sections of 1 1/4" PVC
2- 1 1/4" PVC end caps
1- 1 1/4 " PVC Tee

Other
1- Husky Pressure Gauge
1- Tubeless tire valve ( if you want you can use the valve from an old bike inner tube)

Tools
Saw
Drill
1/2 drill bit
PVC primer and cement

Step 2: Cut PVC to Size

Time to cut . These are the different lengths you need:

Barrel- 2 feet
Tank- 2 feet
2 Joining pieces- 3 inches each

Step 3: Drill the End Caps and Securing the Dohickys

Grab your favorite drill and get busy. You want a 1/2 hole in the middle of each end cap.
The pressure gauge will screw right into the hole, but you still should add some glue to seal it. I used epoxy, but gorilla glue, plumbers goop, and JB weld work fine. Be liberal with your glue!
Thew tire valve won't stay in by itself so you'll need to have pressure applied to it. Use any of the glues mentioned above.

Let these pieces dry over night and your ready to go.

Step 4: Assemble!

Before you start glueing everything together, dry pit all the pieces. PVC cement is a permanent fit, so make sure you know where everything goes. The tank section goes right into the ball valve. Put the Tee on the end of the tank. I positioned mine so it's perpendicular with the ball valve. The 3" sections go into the sides of the Tee and the end caps go onto those. Last, but not least, the barrel goes on the front of the ball valve.

If you want to you can glue the barrel to the valve, but I find it unnecessary. There is no high pressure in the barrel, so it's perfectly safe. it also allows you to put in a different barrel if your feeling adventurous.

Step 5: Glue It All Together

PVC cement and primer give of noxious fumes, so make sure you do this outside. Find a surface that your allowed the stain and get dirty, and bring all the components. Clean and remove burrs from all the PVC parts that will be fitting together. Apply a layer of primer to all pieces then apply the cement. When using the cement, make sure you put the pieces together as fast as possible.

Make sure everything is glued and pushed together tightly. Now you just need to wait for it to dry.

Step 6: Operation and Usage an Trouble Shooting

Now it's finally time to fire your creation!
Attach your bike pump to the valve on the cannon and fill to about 60 PSI
Toss whatever you want down the barrel,D batteries work good.
Point in a safe direction and twist the ball valve!

If your cannon isn't firing, or is barely firing, you probably have leak. Watch the pressure gauge as you pump the cannon to confirm if the is a leak. To the leak, fill your cannon with air and put it in a tub of water. Little bubbles should form where the leak is. Apply glue t that area and allow it to dry. That should fix your problems.

If you want to shoot potatoes from this cannon, take a file and sand the edge of the barrel until it's sharp enough to cut a potato. Try and think up fun ways to use your new air cannon, and experiment with all kinds of ammunition.

I hope you enjoyed this instructables. Feel free to ask any question if I didn't explain something clearly enough.