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Posted: Fri Dec 28, 2007 6:24 pm
by jackssmirkingrevenge
they are called burst disks before they have burst
Fair comment, how about a "used" burst disk then? Not at all confusting (because you can only use it once) and not offensive to the linguistic fascists ;)

Posted: Fri Dec 28, 2007 8:14 pm
by Ragnarok
JSR, I agree, used is the right way of describing it.

Nice simple, but effective design there, shows what some pressure and a fast valve combo can do.

Although I think you're a bit modest when you say "semi decent power" - I'd still need to add almost half as much pressure again over what I'm already using (30 bar total), and finish the valve mods I'm doing to get that same power level with those slug weights - but I would be achieving it with a barrel just under a foot shorter (but with very fractionally higher bore).
I'm actually planning on using that pressure anyway sometime in the future... won't that be fun?

How easy is aiming the thing?

Posted: Sat Dec 29, 2007 12:45 pm
by Hotwired
I vote for the terminology "bust disk" :D

Posted: Sat Dec 29, 2007 1:08 pm
by mark.f
I say the used burst disk should simply be called "chaff", (if it's an Al foil disk), or otherwise the "vacuum frier", (if the cannon were tested indoors. :wink: ).

All terminology aside, great little cannon. Perhas you could acquire a small CO<sub>2</sub> regulator and go for portable, this New Year's, if chamber size permits...

Posted: Sat Dec 29, 2007 1:46 pm
by DYI
I'm going to be away on New Year's, so no go. You could call them chaff, but no one would have a clue what you're talking about (anyway, the "chaff" name is reserved for the remains of the target I shot today, or maybe "toothpicks" would be more appropriate...)

Posted: Sat Dec 29, 2007 2:34 pm
by dewey-1
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Posted: Sun Dec 30, 2007 8:27 pm
by cenzo188
wow nice cannon... im building a metal one how do you get nitrogen tanks[question mark]

Posted: Sun Dec 30, 2007 8:47 pm
by mark.f
You get them from a gas supply, (ideally a local one so you can get refills). Welding supplies are fairly common around here, and they sell inert gases for things like arc welding.

I would suggest SCUBA air if you can't find a gas supply, though.

Posted: Mon Dec 31, 2007 11:24 am
by DYI
Industrial tanks with normal connections (CGA 580 for nitrogen) are far easier to find regulators for than SCUBA tanks. I know you could adapt a SCUBA tank to a 0-500 psi regulator, but it would require a custom adapter, and air is more dangerous than pure nitrogen anyway.

Even most small towns have a basic gas supply, and nitrogen is one of the most common industrial gases, probably behind things like oxygen acetylene, and argon.

Posted: Tue Jan 01, 2008 12:18 am
by clonejoe
I like the full metal aspect. Nice damage shots.