Wblteen's 4" coaxial

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wblteen
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Sun Jun 03, 2007 1:59 pm

Barrel = 52"
Chamber = 51"
sleeved 2 inch golfball barrel.
1 inch moded sprinkler valve
3 inch end cap for piston
I am currently working on a tripod setup, this thing turned out to be a little heavier than anticipated!!
GGDT estimates with a golfball I get 586 fps @ 100psi
The gasket material I use doesn't seem to be able to stand up to the pressures, i get only a couple of shots and then half of the disk gets blown out of the barrel.
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Velocity
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Sun Jun 03, 2007 2:07 pm

Looks nice.. the gasket looks old and brittle though, thats probably why it is splitting. If you want a gasket that does not break, you might want to invest in McMaster Part Number:9013K262. It is a 4" x 36" sheet of neoprene rubber, 1/8" thick, that does not break. If I were you, I would also get a 1.25" metal fender washer to cover the rubber sealing face, so it will be more stable.

I really like this launcher; I myself have never be able to make a successful coaxial (though I have made over fifteen tee valves)... I want to change that soon.
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mopherman
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Sun Jun 03, 2007 2:08 pm

Very nice setup you got there! I hope you find some sturfier materials for you piston issues. May I ask, what is the black thing next to the gun in the fourth picture? Again, very cool
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hi
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Sun Jun 03, 2007 2:25 pm

thats cool. it must be fun to load.

what kind of bumper do you have?

have you tried shooting from your shoulder? just kidding.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
wblteen
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Sun Jun 03, 2007 2:37 pm

The black thing next to the cannon is the pressure gauge which is attached. The gasket material isn't old at all. I bought a 6"X6" sheet when I bought the fittings. Thanks for the washer idea I will be adding it shortly.
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spudthug
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Sun Jun 03, 2007 2:59 pm

have you tried shooting from your shoulder? just kidding
noname jsut built a 4 inch coaxial and i think he shoudler fires it..maybe hip..or maybe im wrong...


btw nice gun! i am currently working on a coaxial... it has a inch inch chamber wiuth a 1/4 barrel..it is all done basically but i need to get a 1/4 pipe tap....then im done...
4" piston valved cannon-half done..( i spilt my cement...)

Hybrid- 75% done. need to build propane holder and drill/tap sparkplug hole..
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noname
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Sun Jun 03, 2007 5:12 pm

"noname jsut built a 4 inch coaxial and i think he shoudler fires it..maybe hip..or maybe im wrong... "

Which coaxial is this? My biggest PVC gun has a 2" chamber. :lol:
Nice gun, you should shoulder fire it, it'll be more fun. :P
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spudthug
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Sun Jun 03, 2007 5:19 pm

hmm it wasnt u? wait let me search i though it was u..srry..

EDIT: ahh...it was frankrede sorry for the confusion lol..
4" piston valved cannon-half done..( i spilt my cement...)

Hybrid- 75% done. need to build propane holder and drill/tap sparkplug hole..
PVC Arsenal 17
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Sun Jun 03, 2007 5:21 pm

noname wrote:"noname jsut built a 4 inch coaxial and i think he shoudler fires it..maybe hip..or maybe im wrong... "

Which coaxial is this? My biggest PVC gun has a 2" chamber. :lol:
Nice gun, you should shoulder fire it, it'll be more fun. :P
If you find that getting thrown on your ass is fun, go for it!
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spudthug
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Sun Jun 03, 2007 5:26 pm

maybe since ur rubber is breaking u should buy a rubber pipe to pipe connection and hose clamp that to your barrel..then u wont need that rubber..
4" piston valved cannon-half done..( i spilt my cement...)

Hybrid- 75% done. need to build propane holder and drill/tap sparkplug hole..
wblteen
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Sun Jun 03, 2007 7:13 pm

Im just going to go with thicker neoprene and the washer. The rubber pipe to pipe wouldn't work, I would need to cut the length of the barrel down.
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Velocity
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Sun Jun 03, 2007 7:31 pm

Why is everyone so afraid of shooting from the shoulder? Yeah, at 100 PSI it would KILL, but at lower pressures (50-60 PSI) with a golf ball, it wouldn't be terrible, especially considering that the cannon is heavy.
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pyromaniac
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Sun Jun 03, 2007 7:40 pm

rmich732 wrote:Why is everyone so afraid of shooting from the shoulder? Yeah, at 100 PSI it would KILL, but at lower pressures (50-60 PSI) with a golf ball, it wouldn't be terrible, especially considering that the cannon is heavy.
I wouldn't be afraid if its pressure rated. i see no reason why. if you think about it if you wasi tfire it and it explodes you have pvc testies.
:pottytrain3:
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turbohacker
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Sun Jun 03, 2007 8:11 pm

Nice gun.
I like the way you made the piston access at the other end of the gun, ive only ever seen it on the vave end- nice work :D
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spudthug
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Sun Jun 03, 2007 9:21 pm

if u hold it good enoguh and lean into it, it would be alrgiht to shoot...it would be awesome to shoot lol...u may get knocked on ur ass a few times but oh well..
4" piston valved cannon-half done..( i spilt my cement...)

Hybrid- 75% done. need to build propane holder and drill/tap sparkplug hole..
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