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Well, I've built about 4 cannons so far. First 2 were your run of the mill inline ones, but very small (2" chambers!). Anyhow, my first large cannon was a 48" 2" barrel with a weird 4" Y connector. No idea on how much fluid it held, but I managed to get propane ignition working on it using a 6" 3/8" pipe. My new one.. well.. I learned from my mistakes. I need to head down to Lowes and pick up the parts for the propane injection system, but I'm going with a different way. Instead of installing the metering valve directly on the cannon, I'm going to try and mount a car rim shrader valve + stem on it directly, then have an air chuck on the metering valve. We'll see how it works out, considering if it doesn't work well, I can always enlarge the hole and mount the valve on there directly (with 1 more piece, a double-male nipple). Anyhow, here come the pics:
and the fullsize image
Obligatory gf with cannon shot:
For the spacer between the chamber and barrel I used a 2" peice of pvc cut down the middle, flipped back to back, then 2 4mm socket head cap screws + washers + nylocks in them. I think I'm going to end up slotting each one, so I can use 2 hoseclamps instead of one giant one. Which would make some sense, considering the barrel is removable. Let me know what you guys think.
Forgot to add some specs, silly me.
24" 4" sch40 pipe for the combustion chamber. With all the fittings, it works out to just shy of 5,500mL. The barrel is 57" of 2" sch40, measuring from the end of the male fitting, to the bottom of the first muzzle break hole. It's actually 6" longer counting the muzzle brake and the knife-edge. Holes are 3/8" diameter, 5 rows tall, 8 wide... should sound funky. Most muzzle brakes I've seen don't use that many holes. Sorry, went off on a tangent...
C/B ratio with that barrel is about 1.8. I think that might be a bit on the EXTREMELY LOUD side, however, I'll be able to change them out pretty quickly. Let me know what you guys think so far.
Yeah, no ignition on it.. yet. I didn't make it downtown in time to buy one of their cheap Chinese tazers. I'm staying up tonight anyhow (damn you night shifts.. on the day off I can never go out during the day). Anyhow, tomorrow I'm going to pick up the tazer, and go ahead and make a pneumatic cannon too (since I have 8' of 4" pipe layin' around..). Yeah, that's my gf, she gets into the things I do
Well got some work done today, and a few test fires in.
Test fires were with a 6" halfinch tube for the propane meter (borrowed off the smaller cannon). Anyhow, I only had old potatoes that wouldn't seal well at all. You'd hear the explosion and see the fire, then along comes the potato. Finally I found ONE that actually sealed well, so I put 3 smaller potatos behind it. I loaded a doubleshot from the 6" meter valve, and.. ignition.. I thought it was going to be a whoomp like my other cannon, but nope, BIG BOOM. And a moderately sized flash from the muzzle brake. Not too shabby. Anyhow, here are some pics:
And the fullsize:
I was originally firing through where the 80mm fan now mounts, with a small electronic bbq pit ignitor, but this is how it's going to be now:
I did end up making a double-point ignition system, using a 1" pvc pipe cut down the middle, drilled holes at the end, then put in a peice of sharpened coathanger. I didn't have time to drill the holes for the inputs tonight though. I didn't have time to get started on the pneumatic I'm making, but I did have a chance to mod 2 of the orbit sprinkler valves today. I think I'm going to spend some time with this combustion for the time being though.
Let me know what you guys think so far.
Lucky bugger, Wish it was the same story over here...I think my hobby repels girls....hmmm jk
Nice guns btw and Welcome to the forums
Last edited by MrCrowley on Fri Jan 12, 2007 5:16 am, edited 1 time in total.
Heh! Not to rub it in, but one drunken day when I decided to cut my racecar in half (after hitting the wall at 80-some mph, broke an axle), she ended up joining in on the fun. I've never seen a girl actually enjoy cutting steel with a torch.. she didn't even wear gloves (mah girl!)
Nice cannon! Fortunate that your girl likes that kind of stuff. I haven't had a gf who enjoys what i do in a while.
Work on the cannon some more, keep the girl the way she is.
Gun Freak wrote:
Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!
Can't ask for a better compliment!!
Does your girl have a sister? Cool cannon, we like damage pics as well. Hey, since your cutting up your car, i see plenty of shotable objects on there! You should join Theopia and do some posting about your race car as well, same guy (PCGUY) owns both sites. You came to the rite place friend, welcome. Before i forget, i think your cannon is the first silver cannon i've seen here. Cool.
When life gives you lemons...throw them back they suck!
Well I finished it up today and put about 20lb through it for *cough* testing.
I also found out one of my dog's toys is a PERFECT fit. It's the rope with a knot on each side, with a heavy rubber ball in the middle. I was able to shoot it slightly more than half a block against 10mph wind (surprised me considering it's so light). Anyhow, new addition is a 2-point ignition system using a 300,000v tazer, with a total of about 5/8" spark gap (combined, each spark gap is slightly less than 3/8"). I ghetto'd it out until I can find a project box the right size to contain the tazer, and to be able to mount switches on it. I've made a few switch boxes (namely one to replace the crappy winch controller on my milemarker winch), as well as every circuit in my racecar. Anyhow, I'll post a picture in a minute or two, that silver paint sure didn't last long, it's easily scraped off, but nothing a pass with a rattlecan won't fix
I went to the middle of the street to shoot the dogtoy at my friend, and a few neighbors were out. One family walked up to me and really liked it, and asked me if I could build a small one for her 13yo kid. Not sure if I should or not... I'd really hate for him to get hurt with something I made, specifically for him, so I don't know.
I'd say dont build it for him,but help him build it himself, Thasts the only way you'll know if he's ready to handle a spudgun and if he is responsible enough. If he is interested in them help him and teach him and build it together.
Nice! I like the silver! I see you are also MUCH better at primer than I am. (Just wait till I post my pneumatic tomorrow, it's a sad job. I guess that's what I get for gluing when a cold front is coming in)
Oh and that girl is one in a million, don't lose her
Yeah, help the 13 yo kid make it. Also, if he's the mischeivious (sp) kind, you might want to mahe him sign a contract or something if he does get one made.
Your end cap threads look a bit gummy, did you use something besides propane as fuel?
Welcome to spudfiles! You might also want to check out theopia, there's always something going on there...
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