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
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
1- Husky Pressure Gauge
1- Tubeless tire valve ( if you want you can use the valve from an old bike inner tube)
1/2 drill bit
PVC primer and cement
Step 2: Cut PVC to Size
Barrel- 2 feet
Tank- 2 feet
2 Joining pieces- 3 inches each
Step 3: Drill the End Caps and Securing the Dohickys
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!
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
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
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.