In this version of a DIY air gun, nothing more than a old soda bottle is used for a air tank and a cheap ball inflator is connected directly into the back of the gun for fast air refills in battle(saves a lot of hassle). The whole project consists of only 5 parts and will cost you 7$ at most. It will as well take only 10 minutes of your time if you have all your supplies on hand.
Step 1: Supplies
Step 2: Idea
-The parts come together in this order-
(Ball inflator)-(bottle)-(threaded end cap)-(ball valve)-(pvc barrel)
Step 3: Firstly
So first using a knife or drill you should drill a tiny hole in the back of the soda bottle, just big enough for the inflator needle from the ball inflator or bike pump to fit through. Next your going to want to drill a hole in the cap of the soda bottle, and into the threaded pvc end cap. The holes should be roughly the same size but it doesn't really matter. Once a hole is drilled in each piece, the two caps should be glued together back to back. You may notice that in the picture a small plastic tube is placed & glued through the hole in each cap. I only did this to make it easier for air to pass from the bottle to the ball valve without any air leaks. You can check if this piece is air tight by blowing into one end while holding the other end shut with your hand. Listen for air leaks.
Step 4: Air Tank
Step 5: Valve+barrel
Step 6: Piece It Together
Step 9: Finished!
-How to fire-
To fire, load a nerf dart,.50 cal paintball,marshmellow, or anything else that fits, down the barrel.
Make sure the valve is closed.
Pump the inflator 3-15 times.
Open ball valve.
Note: 3 pumps will not do you much good, it will send a nerf dart flying no more than 8 feet. Where as 15 pumps will send a nerf dart flying almost 40 feet, depending on the type of dart you using. Have fun! Wear eye protection!
Step 10: Extras
Pvc pipe-home depot-0.50$
Pvc ball valve-home depot-4.00$
Threaded pvc end cap-home depot-0.50$
Soda bottle-recycling bin-free
Ball inflator pump-dollar store-2.00$
How it works:
Knowing how the gun works is just as important as knowing how to make it. So just in case your wondering about how this could ever work, here is how.
When the air pump in the back is pumped, it sends air directly into the bottle, where the air is stored and pressurized after several pumps. Because there is a opening between the bottle and the ball valve, air pressure is able to build behind the valve so that when the valve opens, air pressure is released down the barrel shooting out whatever is blocking its path.
So there you have it, one of the most easy to make air gun designs. Hope you like it:)