Intro: Air Cannon With Adjustable Barrel Size. Bouncy Balls Shot Over 100yrds!
This is my first Air cannon an Instructable i have done. This Air cannon uses compressed air. It is released by a electrical irrigation valve. The barrel is easy to change size. The barrel i used shoots bouncy balls over 100yrds at only 50-40psi. I have tested mine up to 100psi before it started to leak. This is a very easy an fun thing to build. I get a big kick out of seeing a rubber ball flying accross the sky.
My camera has just broke. I will try to post pics up asap. Sry for the horrible drawings an diagrams.
Also the hot glue gun is for making a holder for the 9volts an a mount for the buttons.
Video of it as of July 20th 2007
Step 1: Parts List!! Tools!!!
Hot glue gun
Somthing to strip wire
About 3ft of 2" schedule 40.
A long 1" schedule 20 pvc pipe.
2" slip cap.
2" slip cuppling.
2" x 3/4" Slip x Thread Bushings.
Three threaded reducing male adapters 3/4"x1".
A 3/4" irrigation valve
A theading tire valve. This took me a while to find. It is a metal stem valve, just as one on a bike. It will have threads on the end that gose into the pvc. Rumors are that there findable at autozones an auto suplies stores.
Five 9 volt batterys.
Five 9v battery connecters.
One switch an one push button.
I will get pics up i tryed taking pics but my camera isnt working right now. How convenient!
Step 2: Building the Cannons Compresstion Chanber.
Tire valve to slip cap.
Once you have gotten evreything first you will want to start on the 2" slip cap an tire valve. It is important you do it like this. First find a drill bit that looks to be the same size as the valve. Then test it out on some of the 1" pvc. Drill the hole out an then screw the valve in to make sure the bit is a good size. You want the bit to make its own threads in the pvc. If its a good match then get the cap. Try to get as close to center of the cap as possible. Once the hole is drilled then rap the threads of the valve once or twice an screw it in.
Clean the inside of the slip cap an the 2" pvc. Glue the Slip cap to 2" pvc pipe about 3ft long. Now clean the other end of the 2" pipe, slip cupling, an the reducing bushing. Glue these together an try to keep them even so the 2" pvc pipe gose in an meets the reducing bushing in the middle as best as you can.
Step 3: Chamber an Valve Link.
The chamber an valve link will connect the compresstion chamber to the vavle. Cutt about 5inches of the 1" pvc pipe. Now clean both ends an glue the 3/4"x1 male addapter to the 1" pipe just cutt. Do the same with the second 3/4"x1" male addapter.
Step 4: Connecting Valve to Chamber.
Now using the link you just made Teflon tape one of the threaded 3/4"x1" addapters an screw it into the bushing of the compresstion chamber. Then teflon the other side an screw the valve on. So you have a cannon with out a barrel.
Step 5: Wireing the Valve.
The solenoid only takes 3 9 volts to push it but i like to use 5 so i dont run out of power that often. First run your push button to yor connector. then wire all the connections the same way to follow the pattern. an so the connector isnt turned the wrong way an stopping the circuit from working. Then run to the switch witch will act as a safety.
To test if its working turn the switch on an push the button. If you hear it click then it is working.
Step 6: Finishing
Now Clean an glue the 1" pvc pipe to the last 3/4"x1" addapter. Teflon tape it an screw it in the valve.
To test this i suggest putting a inch of water down the hatch an using a bike pump to pump it a good few times. Then release the button an watch it spray.
I tested mine with a compressor an it didnt give until 120psi. It gave in a connection witch it will always break first. The only time this will shatter is if the pvc has been out in the sun for a very long time an is brittle. I suggest using only new pvc. Also I shoot bouncy balls using only 40psi an it shoots them across the local football field an some.