Current Cannons
This is my most current cannon, I have used the tank in previous designs, but this is the most current configuration. First I'll explain the components, the tank is a 6 gallon steel tank that I found behind my Dad's house. I believe that it was a water storage tank at one time, it is galvinized and has a couple of different fittings on it, the biggest of which was a 3/4" fnpt fitting. Needless to say the first thing I did was to cut a bigger hole in it and weld a 3" coupler on it. In a prevoius configuration I was using a 1" sprikler valve on it, not a big enough valve to feed a 3" barrel very efficiently. I have a bigger valve that I am currently in the process of building right now, but that was for a bigger tank. I planned on using this tank with the 1" valve for a while, it wasn't that high performance of a launcher. But you may be asking, Zeb what is that valve you have on there right now, it doesn't look like anything i've ever seen? Well the answear to that one is, it's the Supah-Valve from The Spudgun Technology Center. I was one of the first four to order one. What it is, is a 3" tee with basicly a valve that Ed Goldmann designed and built to function like a sprinkler valve. It will flow a full 2" of air and open instantly! Yea I know, a 2" valve still doesn't flow good enough for a 3" barrel, but it's ALOT better than a 1" valve!! The rest of the gun is pretty much straight forward, the barrel is 3" x 8' sch 40 Pvc (always use pressure rated pipe, the drain waste and vent, will KILL YOU), the cleanout on the back of the barrel tee is to breach load the cannon.
Now on to the performance of the cannon in it's current configuration. Before with the 1" valve and 105 psi in the tank, I could shoot a 1.5 lb, 20 oz pop bottle full of water, a little shy of 200 yards and through just about anything short of steel. On my first test shot with the Supah-Valve I noticied that I had a major leak where I glued the 3"-2" bushing, so I only filled the tank to 50 psi, I was hoping for better performance, but I was supprised by how much better! I flicked the valve open and the bottle flew far beyond where the bottles were landing with the 1" valve, so far in fact that i couldn't pace them off because I shot it off of my Dad's property, across the main highway and into the woods beyond, all that at 50 psi!! if I had to estimate I would guess that it was shooting about 300 yards, I can't wait to get that leak fixed and fill it up to 100 psi!!
Sept 16 2000
I have fixed the leak and fired with 100 PSI, it's pretty amazing. The recoil is pretty good with a 1.5 lb bottle of water, you can see from this movie. I haven't been able to pace off the distance it fires the bottles because i'm firing them off into the woods. I was also shooting apples from the the cannon, they go right out of sight. I shot an apple at a poplar tree about 70 feet away and blew the bark right off of the tree. I didn't expect the apple to peel the bark off of the tree, but it did, I wish I would have got a pic of the tree. I plan on making some darts to fire out of it soon, and for that matter I plan on getting a page up describing how I make my darts, and how to make the tools to ream a mold for the nose cone which is cast from autobody filler. Well anyway, on to the new pics which should give you a better idea on the breach loading tee that I have on my cannon, and it's construction.