P.C.P.R. (pneumatic coaxial piston rifle).(6mm)(contest)

[CpTn_lAw]

Here is my newest cannon, a coaxial cannon....the barrel is a 8mm OD pipe so it's 6.02 mm ID.

Chamber: 1/2" dia. >>> 30cm long.
Barrel: 6.02mm ID copper >>> 60cm long.
Piston 1.5cm diameter plastic cap, with a 3mm thick neoprene disc glued on it.
exhaust: 1/2" ball valve (F/M) + 90° long elbow (F/F)
Air inlet: quick connect at the end of the elbow.
Air source : 6L extinguisher at 12 bars with my small compressor.

Here ae the pics.


The soldered copper barrel to the brass adaptor


The air source:

The piston: (basicly a cap of little bags of marmalade (pomme-potes))


The rifle connected to the extinguisher:


I will surely post damage pics!! it shoot at least 100 meters in straight shot with a 0.20g BB and acheives muzzle velocities of 220m/s at 12 bars.
I had made a custom projectile made off a tappering of an arrow...shot through a wooden box........

[jrrdw]

Cool, whats the contest? Is the prize if i win? Or did you use the contest tag to get people to look at your post? Good job by the way!

[CpTn_lAw]

well, i've heard about a contest regarding canons some days ago.....i thought it was still open....i don't know the prizes....i just thought to myself, i didn't cost me a buck to participate, and it is funny to engage ourselves sometimes in exceptional things!

[experament_u2]

can any one tell me how can i enter the contest ?

oh btw very clean and nice gun

[POS]

Very nice gun, good job

[SpudStuff]

Nice but it eaves me to wonder why every one is immitating BTB's metal piston guns and the fire extinguisher.

[CpTn_lAw]

First of all, i don't know what the hell is BTB's metal piston, and i use the fire extinguisher for many uses since a year. all i did for this canon, is design it real time when i was buying the materials to proceed in the making. i didn't follow any plans (like for all my other canons btw, i do it all myself)
it's been two years since i bgan building spudguns, and want a fire extinguisher, i found it at a garden sale for nothing...it was free so i thought " hey, that pretty awesome!!!!" and took it back at home...
BTW, thx for the feedback !!!

[CS]

<a href="http://www.spudfiles.com/forums/viewtop ... 746&">Read Up!</a>

jrrdw, where in the hell have you been, this contest has been going on for a while with a fair amount of cannons submitted on here.

Nice gun. I like the small scale perfection of the main body of the gun, although im not a fan of elbowing off into a fire extinguisher. Just doesnt look right :-p No doubt, nice gun.

[Brian the brain]

Nice gun.Looks like a walking cane!!

The extinguisher is used in a completely different way than I use it.
My sawn off is over-under.THis one is coaxial, so that's also different.
The only thing I recognise as being thought up my me first is the handle.
Makes for a cool look but it not something too unique.
He could have thought it up on his own.
If he copied it....WHO CARES???
I don't!!
Nice gun

BTB...that's me!

[jrrdw]

Ive been around, but it seems it got rite by me. Since i'm not the only one wondering about it, auther of post not sure if it's still going on. You should repost the contest in case someone else has missed it.

[CpTn_lAw]

well, thx everybody for the positive feedback!! I thought this on my own!! i don't like to copy things cause they loose all their creative aspect!!! so even if i find something cool, i might use the principe but not the look and design.
my grandpa soldered the barrel to the adaptor and machined a copper piece to reduce the space before soldering...so this is supposed to resist 2500+ bars , much more than any compressor could give, and much more than the gal.steel pipe max pressure...not to mention that it's perfectly air tight

[schmanman]

nice, clean gun! how many psi do you put in it?

[CpTn_lAw]

i have been able to put between 40 and 200 psi. for all pressure before 130 psi, i use my compressor and extinguisher..but for higher pressures, i use my high pressure pump...but honnestly, pumping to 15 bars is very hard!!!
For the pup use i've made an adaptor, which isn't in the pics. it's made of a quick connect (female) a 3/8" ball valve (for safety) and a tire valve with some epoxy on a 3/8" => 1/4" threaded reducer. very simple...

[Mitchza89]

Hey mate just wondering, if you use galvanised pipe as the chamber...how did ya get the piston to move smoothly? I thought the inside of gal was really rough and distorted :S

[frankrede]

its not that bad really, I have used a piece for a barrel and it was fine.