How to Build an Air Cannon

Introduction: How to Build an Air Cannon

What is an air cannon? For those who don't know, It's a gun that shoots stuff by using the power of compressed air. You pump up the gun, flip the release valve, and it shoots whatever you put in it out at high speed. For ammo you can put anything down the barrel. if you choose to use smaller ammo that doesn't fit down the barrel, just attach a smaller barrel.

This build is relatively simple, and doesn't require much experience, so anyone can do it.

I made mine out of galvanized steel pipe, but it cost $50. I don't  recommend using black steel pipe, because it is rusty on the inside, and has an odor. If you want to adapt this design to use PVC pipe, it should cost less. If you want to use an air compressor, instead of a bike pump, it should be easier to pressurize (obviously).

Step 1: What Do You Need?

You can get everything at your local hardware store.

Here is what you need:
- 2: 1/2" x 1" galvanized steel nipples
- 2: 1/2" brass ball valves
- 1: 1/2" x 3' galvanized steel nipple
- 2: 1/2" to 3/4" galvanized steel bushing
- 2: 3/4" to 1 1/4" galvanized steel bushings
- 2: 1 1/4" galvanized steel  couplers
- 1: 1 1/4" x 6" galvanized steel nipple
- 1: 1/2" x 1/4" brass bushing
- 1: 1/4", NFTP, industrial plug (male)
- hot glue
- bike pump or air compressor

Step 2: Some Assembley Required

below. Aftertures below are pretty self-explanatory. Assemble it as you see below.

After you have done that, put hot glue around every connection EXCEPT the 1/2" x 3' nipple. That way, your connections are air tight (without the glue, all the air escapes, and you can't get any pressure).

Step 3: Check for Leaks

Close the bottom valve and open the top valve. Pour some water down the barrel. Attach the pump or compressor. Close the top valve and open the bottom valve. Look for bubbles. Apply hot glue to the leaks.

Step 4: Fire!

fire. Hereitem you wish to fire into the barrel. Push it down until it hits the bottom with some kind of rod. Close the top valve. For ammunition, I recommend using nerf bullets, markers, blue berries (they go splat), or anything else that fits down the barrel. Attach the pump or compressor. Pressurize it to at least 100 PSI. If you would like to detach the pump or compressor, close the bottom valve. Open the top valve to fire.

Click on the video to see the air cannon shooting a nerf bullet at about 100PSI.

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    7 years ago on Introduction

    I made this with a short and compact barrel and a large tank to store more air for higher power. I have an end-around design to save space and added a pressure gauge. I use an electric bike pump to pump it up.


    Reply 7 years ago on Introduction

    Oh, and by the way never use PVC for air cannons.

    Slim dawg
    Slim dawg

    9 years ago on Introduction

    I have bought the materials and have assembled them correctly, but I am unsure as to how to hook up the bike pump. could anyone help me with this issue?


    Reply 9 years ago on Introduction

    Remove the piece that connects to the bike valve (I was able to just unscrew it). Then stretch the hose around the small end of the air cannon. Use a bike pump only if you don't have an air compressor. The hose will pop off after 135psi. If possible, use an air compressor. The air cannon has a quick-connect piece on the end so it will always stay connected. It won't just randomly pop off. I highly recommend you use an air compressor! I just used a bike pump because that was all I had.

    Good luck!


    10 years ago on Introduction

    I would like to suggest that all high pressure air cannon instructables should include a warning on page 1, such as:

    "These high pressure air weapons can shoot things fast enough to cause severe injuries or death. Never use them to shoot things at people."


    Reply 10 years ago on Introduction

    Well, duh. I think the word "cannon" gets the point across.


    11 years ago on Introduction

    feakin awesome! shot a 1/4 inch marble over like 10 houses!  however, a little suggestion instead of using hot glue, use jb weld.  best air cannon ever.