School Cannon

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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D_Hall
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And just for grins I just simmed: 3"x12" chamber, 100 psi, 3/4" QEV, 3"x24" barrel, 1 lb projectile...

103 fps.

I'm gooood. ;)
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STHORNE
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D_Hall wrote:And just for grins I just simmed: 3"x12" chamber, 100 psi, 3/4" QEV, 3"x24" barrel, 1 lb projectile...

103 fps.

I'm gooood. ;)
Hey! I was gonna say that.... :(

lol, nice work and ugh....yeah...I guess your "good" lol
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Ragnarok
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daberno123 wrote:BTW Ragnarok- Love the new sig, where'd you find it?
Ah, well, if I see an amusing quote, it will often become a new sig. I found it when doing a search for the exact wording of another of Douglas Adams' quotes:

"Mark Knopfler has an extraordinary ability to make a Schecter Custom Stratocaster hoot and sing like angels on a Saturday night, exhausted from being good all week and needing a stiff beer."

... Which he said about the guitar in Dire Straits' "Tunnel of Love"
If you think about it too much, it makes no sense, but it's the most damned accurate description of the playing I have ever heard.

But I found the potato one at the same time, it's one I've seen before, but on seeing it again decided it was appropriate for the forum.
Does that thing kinda look like a big cat to you?
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jrrdw
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I would get this and add this! For under $100.00 bucks, can't go wrong! Sometimes I scare myself.
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Ragnarok
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jrrdw wrote:Sometimes I scare myself.
And sometimes I scare other people. It's more fun that way.

Whenever there is a problem and they say they can't think of a solution, just tell them you've got a plan involving a dirigible, two ducks and half a ton of explosives - you'd be surprised how often they do actually have a solution.
Does that thing kinda look like a big cat to you?
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MrCrowley
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With my 4"x1' chamber, a 1" sprinkler valve and a 3"x1.5' barrel, I launched a t-shirt easily 50m at 80psi.

Either go with the 3/4" QEV or the 1" sprinkler, just reinforcing what everyone else is saying.


I accidently posted this in the 'Badge thread' :lol:
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daxspudder
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okay, i dont really have any useful input for you, but even the weakest setup is gonna yield at least a 50 fps muzzle velocity, and i know if i wanted a hotdog, i wouldnt want it coming at me like that, unless wrapped, even then a hotdog is a relatively heavy compact(wrapped) projectile, so my thought is to recommend to your principal that its for shirts or confetti only.... i can just see the headline/lawsuit "high school student pummeled with hotdog loses eye" lol.
clide
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I've just glanced over the rest of this thread, so sorry if it has been pointed out before. We had a member hear who was fond of making t-shirt cannons, but one of them exploded injuring many and I believe his dad lost an eye. So I would suggest metal for something that is going to be used in a crowded place. If you can't go with metal then just make sure it has a pop safety valve to prevent over pressurization.
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MaxuS the 2nd
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And you have to remember that some fool will most likely drop it whilst pressurised.
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rcman50166
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Yes, this is true. Make sure you make it extra weak then! JK. To make it dropable you should use pipe insulation to cusion falls, also you want to make sure there aren't any leverage points on the gun for gravity to take advantage of. (Corners, thin points, etc.) Make the cannon idiot proof too. Add a strap on the handle to make sure some couldn't possibly drop it. ( or throw it like the whole Wii Controller incident :) )
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Carlman
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rcman50166 wrote:( or throw it like the whole Wii Controller incident :) )
haha that has happened to me to, damn golf :roll:
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Ragnarok
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Carlman wrote:haha that has happened to me to, damn golf :roll:
Golf? I find it's most likely with the Tennis...

There's actually a video of me and some mates playing Wii tennis with me and a couple of mates in the next room from the Wii with the controllers, and a group in the other room shouting instructions.

It worked surprisingly well until we forgot who was giving each of us instructions, whereupon flailing ensued.
Does that thing kinda look like a big cat to you?
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n-strike
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I think you should do some testing what psi would be best for shooting shirts.
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