The Mean Green Uber-Awesome Machine!

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
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noname
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Thu May 31, 2007 12:02 am

I made this Monday, when there was a 10% off discount at OSH, so it's slightly thrown together, but I think it turned out pretty good. The chamber's about a foot of 2" steel, and the rest of the gun is either steel or brass. The ignition is a single spark BBQ igniter, with one wire through a 1/2" aluminum rod and the other wire attached to the chamber wall. The spark jumps from the inside of the chamber to the chamber wall; it's pretty simple. The barrel is 10 feet of 1/2" PVC, and I usually shoot ball bearings or rifled potato pellets. I've shot a couple times at 2x, but will go to 5 or 6x when my mixing tank is back at my house.

I gave it a chrome green paintjob, but the camera (VERY disappointed here) really doesn't show it. The shade of green that shows is more bluish, and it's actually prety dark green. Oh well, pictures for all of you!

Those of you who have made burst disc cannons know it's damn hard to get over 6 layers of aluminum foil to seal, right? So make burst discs from chip bags! It's some type of mylar, and by the pics you can see they burst extreeeemely well, and seal 100%. Just one layer was tested pneumatically and took about 130 psi to burst.
Attachments
The union
The union
Check out how well that burst!
Check out how well that burst!
The ignition setup
The ignition setup
The fill valve
The fill valve
My mix guage, protected by a ball valve.
My mix guage, protected by a ball valve.
The front and union. Anyone think a reducer shaped that way could help focus the flame front? Even a little?
The front and union. Anyone think a reducer shaped that way could help focus the flame front? Even a little?
The whole chamber. I am very disappointed my camera didn't get the color, sorry everyone.
The whole chamber. I am very disappointed my camera didn't get the color, sorry everyone.
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origin unknown
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Thu May 31, 2007 12:05 am

Nice job! Ha ha, It looks like severely oxidized copper.
Ecclesiastes 1:9 - What has been will be again, what has been done will be done again; there is nothing new under the sun.
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noname
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Thu May 31, 2007 12:07 am

Hater............ :lol:
That second to last picture is scary. The fittings look crooked as hell. :lol:
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A-98
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Thu May 31, 2007 12:25 am

*sigh*
I need to get around to making a hybrid

one day....one day....
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Killjoy
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Thu May 31, 2007 12:58 am

Very nice, its nice to see my hybrids around. Any chance you'll get to chronograph it and add some damage pics?
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origin unknown
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Thu May 31, 2007 1:14 am

noname wrote:I gave it a chrome green paintjob, but the camera (VERY disappointed here) really doesn't show it. The shade of green that shows is more bluish, and it's actually prety dark green.

It was probably your cameras flash that screwed up your pics. If the flash was on when you took your pics, then that is what messed them up, and you need to turn the flash OFF.
Ecclesiastes 1:9 - What has been will be again, what has been done will be done again; there is nothing new under the sun.
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mark.f
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Thu May 31, 2007 9:28 am

The hybrid looks good! I have no specifics on how fast a 10 foot barrel connected to a hybrid chamber will accelerate a marble, but my guess is pretty damn fast!

You might want to consider a fluid-volume measurement of both the chamber and your meter pipe, (if feasible). That way, you can go up to higher mixes like 4x-5x in such a small chamber without experiencing ignition troubles. Or, you could make a Generation Two fueling tank.

As for crooked pictures, I find that if you take a picture directly over and objecet, so that it forms a 2-D image, you get crooked results. I usually try to have my pictures going on an oblique with a vanishing point somewhere, because it represents orientation and straightness better.
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Fnord
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Thu May 31, 2007 10:10 am

Wow.. It's so .. simple.
Where are all the pipes and hoses and valves??
Great looking gun. have you considered powder coating it instead of typical spraypaint? It looks good as it is though. Like its coated in green glass.

By the way, will your ignitor handle 5x? you'll need a really small gap.
Image
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noname
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Thu May 31, 2007 7:10 pm

Damage pics will come after my mixing tank comes home.

Chronograph...hmmm....doubt it, unless the paintball place will let me see how fast it shoots.

Origin Unknown, I don't know where to turn off the flash. :lol:

Mark, my mixing tank is similar to a Generation II tank. It is a larger pipe with the propane meter attached. I inject propane up to 8 times usually, then pressurize it with compressed air to the right number of atmospheres. The tank has a hose with an air chuck on it, so I can fill the ignition chamber to whatever mix I want with via the schrader valve on the back.

Fnord, I'm a money scrounging 14 year old, I made it as cheap as possible. :lol: I think it will ignite a 5x mix. If it doesn't I can simply unscrew the compression fitting, move the wire closer to the chamber wall, and screw the fitting back in.
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Fat Pants
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Thu May 31, 2007 7:32 pm

Flash woes: Tear off a square of normal white paper (not too small, maybe 7cm by 7cm) and hold it over the flash, making sure your fingers aren't in the way and get snapping. Maybe double it over if it's still too bright. Sorted. (came up with it myself a couple of days ago, no doubt it's been done before though)

Nice cannon, I'd love to make a hybrid one day, they're so powerful!
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fastcannonman
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Thu May 31, 2007 7:38 pm

can u get a pic of the barrel?
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zeigs spud
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Tue Jun 05, 2007 1:35 pm

origin unknown wrote:Nice job! Ha ha, It looks like severely oxidized copper.
ha thats what i was thinking!!!! yea that is sweet. love the color.
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