SpudFiles

Cannon Name- EVO4
Type of Cannon-Pneumatic
Valve- metal barrel sealing
Exhuast- Low pressure- Hunter Jartop sprinkler valve (looks crappy)
-High pressure- 1/2" ball valve
Main ammo- Nails sharpend both sides and tempered.

Right now I have the sprinkler valve on it for the best preformance at low pressures. It does make it a little ugly though. But at high pressures (when I eventually go to high pressures) it just has the ball valve as the exhuast and trigger and looks sweet.

All metal design, very tough and it has an ultra light piston made from a bolt and some nuts and rubber washers. It has no pressure gauge and nothing fancy on it, which makes it really easy to operate, really easy to make and leaves it compact, portable and easy to modify.

Lots of work and time has gone into this project and as a result has made a spudgun with few flaws. Not bad for my first piston valved cannon, first metal cannon and fourth ever cannon. All the wall of doom episodes were made with this cannon, here is episode four(which is the best one):

sweet gun, i love the look of it. about how much did it cost to make?

Well, the amount it is worth now is about R150 (without the sprinkler valve), like $30 USD. But I put at least R300 into the developement of it all.

Make sure you watch the WALL OF DOOM, episode#4. You will like it.

I like it Alot!! I like how much its evolved from the start till now. The piston is very simple and and i bet its pretty light. Did you notice a big difference in power when you upgraded to a sprinkler valve? All these new piston cannons are making me crazy! I need to build one.

I like you arm. Its soo veiny....

Thats awsome! what pressure can your sprinkler valve hold up to, coz having a metal gun it would be great if you could take it up to some high psi

its okay dont like the metal that much though cool gun anyway

The piston also has a spring behind it. There was more power when I added the sprinkler valve and it did change the sound more like the a real shotgun but it should only make a difference at low pressures. The sprinkler valve is rated for 10bar, 100 psi is about 8bar.

I was planning to do more to the shotgun but when you don't have the right tools and enough cash it can be difficult. Owell, there will be many more.

100 psi is about 7 bar, not 8 (which is about 115).

10 bar is almost exactly 145 psi, which is enough for a very decent amount of power.

Ok, just came off the top of my head anyway.
All I need to do is make a high pressure pump.

How high pressure?

If you want to/don't mind buying something, some bicycle track pumps will do 10 or 11 bar, and some will even achieve about 15 to 16 bar - which is really quite impressive, and enough for most peoples purposes.

Except perhaps Brian the Brain.

and me, i wanne pump that goes up to 20 bar (almost 300 psi) for my copper cannons.

I shot it at 9 bar (130 psi), it shot a marble of 25 mm (the big ones) staight trough a 3 cm thick wooden plate at a distance of 20 to 25 yards. I can imagine (and wanne find out) what it can do at 300 psi

The pump I use is a SKS pump, cost me about 50 euro's.
if you really push it, it can reach 22 bar, but it's only supposed to go to 16 ...

A better option might be to use regulated CO2..

And yes...If I would be confident about the building materials I would like to go to 40bar, or possibly unregulated CO2.... but I don't trust galvanised steel to take the pressure safely...

you could try it out, by filling it with water first, and then put it in a bathtub before pressurising it. In the worst case, the steel will break, but don't explode.

If you try filling it with pressurized gass only, and the steal cant take the pressure, it will surtanly explode and make casualties.

It looks great still w/ the sprinkler.
You got some sweet screencaptures from episode#4.

I would trust that Gal steel at 300psi,the Gal steel parts from around here are rated to 25bar.BTB is that pump a shock pump for mountain bike shocks?