Reaper's hybrid ALVAU

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
reaper613
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Thu Oct 12, 2006 11:17 am

somtimes the potato will be pushed out of the barrel but its not really a proplem b4 around 20psi, even then it is rare if i have a good potato.
and although the video dosent show what this gun is capable of consider that when the nilon slug hit the sign, it hit it not on its point but sideways and still blew through just look at the shape of the hole
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CpTn_lAw
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Thu Oct 12, 2006 1:20 pm

I am just amazed....this is by far the sweetest cannon, and i'm everydays on spudfiles, that i have seen in a long time. Reaper, you made this one really great...respect, and admiration! :o :o
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Extrusion
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Thu Oct 12, 2006 1:20 pm

Wow thats is crazy powerful holy crap man that is one awsome gun and sorry if i missed it somewhere but why do you choose the not use burst disks?
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Velocity
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Thu Oct 12, 2006 6:02 pm

Awesome hybrid dude! I like the SCH 80 PVC ones, but I just don't feel that they are safe. When someone welds together a metal hybrid as you did (these are very rare), it is obviously much safer. You must feel pretty safe, considering you hand held it :lol: , not remote fired.

One suggestion: Increse the barrel size! You say your chamber is 3" by 24", right? This is about 54 pi cubic inches. The barrel is 2" by 48", giving it a volume of 48 pi cubic inches. This gives you a ratio of 1.125:1 C:B. Because hybrids create such massive pressures, you can have a very low ratio (0.3:1) and get much greater power. If you double the barrel length (actually, if you need to go out and buy a barrel, just use the whole 10' stick of 2" copper). The increase in power will be ENORMOUS! Noise will be down as well. Problem is, portability will suck, and I am not sure how it will affect the balance when it is on the stand.

Anyway, awesome job dude :D
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ProfessorAmadeus
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Thu Oct 12, 2006 7:10 pm

Copper is SOO expensive though. It cost like 22 dollars at home depot for 3/4 in by 10 feet.
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reaper613
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Thu Oct 12, 2006 8:40 pm

im happy with the barrel length, but i also have another 5ft piece of copper pipe and a coupling so if i wanted i could double the length. what i am getting next is a 2"redbottle muffler (hopfully somone knows what that is) to use as a silencer. its only $30 and should make the gun quieter for those nightime firings. i already had a cop drive up to my neighbors house and turn around, if he had come another 50ft he would have seen my friends and i with the gun and that would have been bad.
squeaks
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Thu Oct 12, 2006 8:47 pm

I like your hybrid man. I've been trying to find a good propane meter design, but I've failed miserably, could you refer me to one?
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Extrusion
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Thu Oct 12, 2006 9:04 pm

Propane meters arent that hard just 2 ball valves wich the little ones are very cheap around here youll need a pressure gauge and torch head for the propane then hook um up like this...

Anyway i think you should lengthen the barrel there will be a big increase in performance lol ever thought of trying to break the sound barrier with this totally awsome hybrid?
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Turn on torch and turn the first ball valve  when the guage reaches desired PSI turn off propane and close the first ball valve now open the second valve untill the guard reaches 0 psi then close that valve and fire lol<br /><br />Experiment with different psi's for the guage.
Turn on torch and turn the first ball valve when the guage reaches desired PSI turn off propane and close the first ball valve now open the second valve untill the guard reaches 0 psi then close that valve and fire lol

Experiment with different psi's for the guage.
cheap propane meter.JPG (7.34 KiB) Viewed 3838 times
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Velocity
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Thu Oct 12, 2006 9:36 pm

I personally would not simply weld on a barrel extension. Especially on high powered guns, there is a very good chance that the projectile will "catch" on the barrel extension, and blow it off.

You could probably just get a 10' 2" PVC SCH 40 barrel. Sure it wouldn't look as cool, but it would function alright...
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MrCrowley
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Thu Oct 12, 2006 10:03 pm

ProfessorAmadeus wrote:Copper is SOO expensive though. It cost like 22 dollars at home depot for 3/4 in by 10 feet.
i pay $22NZD($13US) for 1metre(3') of 1" copper in New Zealand :evil:
reaper613
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Fri Oct 13, 2006 1:08 am

pvc barrel would blow out after the threads get weak from the heat, and after 10 spuds in a row my gun gets pretty warm
reaper613
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Sun Oct 29, 2006 10:24 pm

here are some pics of the nylon bullets that i use
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here are the older ones
here are the older ones
PA290064.JPG
PA290063.JPG
here are the new ones, they go a lot farther due to the rifling and tapered edges at the back
here are the new ones, they go a lot farther due to the rifling and tapered edges at the back
PA290060.JPG
PA290059.JPG
squeaks
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Sun Oct 29, 2006 10:30 pm

sweet, how did you make and rifle those?
reaper613
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Sun Oct 29, 2006 10:40 pm

my cousin made them on a cnc lathe
squeaks
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Wed Nov 01, 2006 10:16 pm

You lost me at the cnc part. What is a cnc lathe?
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