The Canon on Air Cannons

Posted by Cory R. "Click" Starr - CSE Special Engineering on Thursday, 13 November 1997, at 12:57 a.m.

Mike Walling knows of several high quality solenoid air valves that will probably make constructing your air cannon quite a bit easier.

What you are going to need to do is this: Purchase an 11 gallon portable air tank (Campbell Hausfeld, among others, manufactures these). Drill at least a 2 3/16" hole in one end of the air tank. In this hole you will insert at least a 4" length of 2" black pipe nipple - be certain to grind or burn off the black corrosion coating around one end of this nipple. Insert the nipple into the hole, you may even be able to thread it into your hole, depending on the size you have drilled. Weld the nipple to the tank, making certain that the weld is airtight (much harder than it sounds!!!). Thread a 2" ball valve (or solenoid operated butterfly valve that Mike Walling will provide info on) on the end of the nipple.

Here's the tricky part: If you can get the valve that M.W. is speaking of you are pretty much done, and this is the easier of the two methods. However, if you use the ball valve, you will need to attach a pnuematically operated cylinder to the handle, provide a 5 way air valve, and various pneumatic plumbing for actuation. If you can get the solenoid valve, get it, it will save you MUCH time, effort, and money. But in defense of the pneumatic cylinder and ball valve, it looks awesome when it fires!!!

You will need to get these also: three 2" galvanized elbows, four 2" x close galvanized nipples, one 2" galvanized flange, and one hopper. The hopper can even be a steel cooking pot. The first nipple screws into the valve, the first elbow screws onto that nipple, pointing down. The second nipple screws into that elbow, whereas the second elbow screws onto that, pointing sideways. The third nipple screws into that elbow, while the last elbow screws into the nipple, angled up by 45 degrees and pointing away frow the tank. The last nipple screws into that last elbow, and you screw the flange onto it. Got it?! Drill a 2" hole in the bottom of your hopper and weld it to the flange.

Now don't tighten up all of those elbows and nipples too tight, you want to be able to move them so you can aim your hopper where you want it. Fill your hopper with lightweight debris, such as fullers earth, vermiculite, lichen, cork, water, etc. NEVER use anything that is hard or sharp, or that could injure anyone if they get hit by it. Fill the tank with compressed air to about 150 psi

!!(Don't go higher unless you have an ASTM certified welder weld the tank for a higher pressure)!!

When you fire the valve from a remote distance, it will simulate an explosion. Neat stuff.

Good luck.

Click