100psi Hand Held Self Contained Air Cannon
This is a relatively simple device bodged together from junk I had around. Take some PVC parts, an old tire inflator, solenoid, capacitor, inverter and various other stuff, and you end up with something like this:
Watch out! This sucker is powerful…and can be seen in this video:
The design consists of a tire inflator compressor strapped to a PVC air chamber. In the rear the air goes in via the fittings seen below. The air is released from the front via a solenoid…it’s rated 48v…but it won’t trigger with 100psi at 48v, so I rigged up a capacitor to feed it 200v or so for a split second, enough to shoot perfectly. The short duration causes no damage to the coil in the solenoid, but not all may be as rugged as this one – YMWV. This one came from a junk box.
The air fittings at the rear allow the pressure tank to be charged. I also have a valve on there because those quick fit compressor fittings leak a bit, and I like to use a large compressor sometimes . The tire compressor came with a tire filler end, which I chopped off and stuck a quick fitting on to…this way I can disconnect the attached compressor and charge it from a big compressor for faster recharge.
All air pressure tanks should have a pressure gauge for safety…PVC is pressure tested to 180psi, so 100psi is nothing for it. This gauge is also necessary for external filling. Even with the safety measures I always wear thick goggles and hearing protection when using this device.
PVC is made to carry water most of the time, and the fittings don’t seem to be completely air tight. To solve this I routed around the edge to form a valley which I filled with epoxy. This sealed the sucker permanently, though I dropped it and it leaks a little now.
Those cheap little compressors aren’t made for continuous use…so I took it apart and installed a cooling fan. Without this the motor would burn up in a couple of shots. I still only charge it every few minutes to give it cool down time.
The solenoid/capacitor system requires high voltage. The gun operates off of 12v, so I needed an inverter to get some higher voltage. This came out of a junk box, it’s just a small self contained 12v step up inverter. Charges the cap in a few seconds for firing.
The actual firing system. When the trigger is pulled, the cap is dumped into the solenoid, which opens instantly and releases all the pressure. Whatever is stuck down that barrel comes out with ferocious speed, and is certainly lethal, if you see what it did to the sheet metal in the video above 😉