SpudFiles

Iv been into spudguns for about 2months and have made 3 combustions 2 of whitch were a great success (the other one, the end caps blew off). This is my first pneumatic, a little about it.

Barrel: 15mm wide
Chamber volume: 721ml
Valve: 1/2" ball valve
Pressure: i usually fire it at 120psi, but have had it to 180psi once.

The first pics show it before i moddified it, it wasnt really powerful so i doubled and a half the chamber, and it is hella powerful now. It went through 1/2" plaster bord as if it was paper and can shoot about 200+ metres, and is very accurate, unlike my combustion witch were all about power, as i can look straight along the barrel.


This is the not very powerful version.


The shrader valve on the compression fitting end cap i used.


New and improved!


Showing the Ball vale open and the new place i put the shrader valve.

cool, what r u firin out of it

very slick. ive been wanting to make my own metal cannon but no money

i bet it can hold alot of pressure.. however there are a few flaws in teh design, first of all you create alot of friction from all of the bends in the chamber, this will make you lose a bit of the force, as well as create a kick back, in your future designs try to have as few bends in the chamber as possible. it will help you to get the maximum power from your cannon.

~FLINCHY~

I use the same materials.U can go up to 300 psi with those copper tubes but make sure you compress those fittings as tight as they can go.( popping off an endcap at 300 psi isn't fun.)
You can greatly improve the gun by making your own piston valve.Look it up in the wiki if you don't know about them.
That will make a huge difference.Forget the loss in performance created by the bends.It's not that big of a deal.
Look up some of my guns if you like those brass compression fittings.( like freaking lego!!!)

yea, if your only using 120 psi you should get a modded sprinkler valve or piston valve (same thing kinda) also you could make the barrel a little longer.

i couldnt make the barrel longer as thats the longest peice of 15mm pipe i had.

i couldnt have less bends as it would be about 2-3 metres long as the chamber needs to be long with only being 22mm wide.
The only thing i worry about if i take it any higher pressures is the shrader valve will go, i know some copper pipes can up to 00psi.

oh and i fire potatos

thats a cool gun dude,good job.

very nice, i'm goin to make my first pneumatic soon due too my dislike in the efficiency in a combustion, although your cannon is very nice and looks powerful, every tried shooting marbles or batteries?

i cant get baterys to fit in

try marbles,you get lots of various sizes

have u tried AA and AAA, surely they would fit in a 15mm barrell ? By the way what do you use to pump it up? compressor? how long does it take ?

I think it will be a total waste if you don't shoot at high presure.

I was using a 12v compressor and regularly taking it upto 200psi, as my confidence grew because this is my first pneumatic, but then it broke, as it was only a cheap one. So now im using a cheap bike pump and only taking it to 50psi and its still pretty powerful, but when i get a new compressor