In this tutorial i will be showing how to make a pneumatic air gun. Its an interesting build that utilized air pressure that is hand compressed in a piston and released through a valve to fire a projectile. The materials were bought at hardware stores (will be listed on materials page) but as a few are expensive so i recently came with a version made with more obtainable materials such as syringes new version . But, you can see a short preview of the syringe version working in the video of this gun attached above.
Step 1: Materials
For this build you will need some tube, a valve, and a piston. all of these i found at princess auto which is an auto and farm surplus store. I also bought an aluminum hollow tube for the barrel of the gun and a solid steel pipe that fits perfectly inside the aluminum tube to make an airtight seal.
Step 2: Making the Bullet
I first cut the aluminum barrel down to 55cm. After that i went ahead and cut the projectiles out of the steel pipe to an approximate length of 2 cm for each projectile
Step 3: Preparing the Valve
Next i cut out 2 pieces of the plastic tubing and pushed it into the back two holes in the valve.
Step 4: Attaching the Valve
Next i flipped the valve upside down and glued its flat side. Then i placed the piston on the glue and attached one rubber tube from the valve to the back of the piston so that when the piston is pulled in it will force the air into the valve.
Step 5: Preparing the Barrel
Next the aluminum tube was attached to another rubber hose by pushing the hose over the tube
Step 6: Attaching the Barrel
The aluminum barrel was the glued onto the piston and the tube from the barrel was connected to the other side of the valve so. The entire flow of air now goes as follows: the piston is compressed and the air is forced towards the valve. When the valve is in the closed position the air does not flow through the other side, so pressure builds up inside of the tubes. When the valve changes positions the air flows into the tube on the other side of the valve and the high pressure air flows into the barrel of the gun, propelling the bullet
Step 7: Attaching the Butt
To finish off the project i found a large metal piece of pipe. I hammered it narrower near the end to create the butt of the rifle and attached the other end onto the back of the piston so that the butt of the rifle can sink into your shoulder as you fire