Metal Advanced Ball Valve Cannon

[jazzman56]

Gday all

This is my 3rd air gun, 1 combustion and 2 pneumatic. The combustion launcher failed and took many a click to get the gas to ignited. My second was a simple PVC ball valved air gun. Here is my 3rd (second working) air gun.

The Negotiator

This is my first working cannon that i've made that i'm satisfied as i have very limited tools. (The Negotiator). I wanted to keep it simple and cheap, with still considerable power. It has a simple stock, spring loaded valve (to keep it reliable) and a breech loading barrel. All joints are teflon tapped and are air tight. Through the barrel support together with spare parts and keeps the barrel secure enough



Specs:
Barrel: 60 cm by 1cm copper tubing
Chamber: 20mm by 200mm (2cm times 20cm) galvanized steel
Valve:Oiled Spring loaded 3/4 (20mm) ball valve (yes i know it's a ball valve)
Ammo: triple A batteries + anything that fits
PSI: 160 psi
Trigger: Fire extinguisher pin (attached to length of para cord)
Fill Valve: Schrader pushed through a brass end cap epoxied in.
Sights: No sights. Any ideas???

It took 30 min to drill the F*&%^ing hole for the schrader valve large enough. What bit is the best for brass??

PICS









To come:

1.
Looking forward to making a piston/hammer valve capable multiple shots (using a 1 liter powder fire extinguisher via a pressure rated hose from the 10mm nozzle) to fire 4.5mm bb's.

Questions:

Where do i get a 4.5 IB barrel???

Any ideas on how to construct a hammer for a blow gun???

Where to get sealing face/gaskets????

Should it be hot glue or washer piston?? (which has better performance)


2.
Gippedo's Homemade pump


Any comments and criticism welcome.

3.

Fridge Compressor (Hopefully)

How do i get the froen out of the hose??? sidecuters

[wyz2285]

1. I´m making a tutorial for how to make a hammer valve from a blowgun, search a little.
3. Just cut a small hole on the tube, let the froen leak until there is nothing left, then cut it all

[nathanhd123]

First off nice gun. However the zip ties make it look a bit messy along with the block of wood.. Have you tried carving a stock? Also how safe is that fire extinquisher pin as you dont wont that misfiring.

For the sealing face you just need to find some thick rubber,neoprene sheets are good, and cut it size. Then use a small screw and a washer to keep it in place and screw it into your piston.

How about some damage pics?

[Doctore]

Nice airgun!!!
You should use threaded shrader valve so you can safely go up to 300 psi

[Crna Legija]

Where do i get a 4.5 IB barrel???

Go to hobby stores they have lots of small id brass tubing, take a bb with you and test fit.

Any ideas on how to construct a hammer for a blow gun???

Do you mean the striker? you can look up zip gun on YouTube and use that trigger mech they use, just replace the cartage with valve stem.

Where to get sealing face/gaskets????

Bike/car/truck tire inner tubers or bunnings.

Should it be hot glue or washer piston?? (which has better performance)

If they have the same fit you wont notice any difference, i reckon hot glue pistons good place to start, when you bump up the pressure then make a washer one.

Gippedo's Homemade pump

I would buy a check valve that can handle the desired pressure not make one because if it fails your pump rod will shoot back like a air ram and can deal some serious damage. It happen here to Brian the brain the handle broke his jaw.

Fridge Compressor? sidecuters???

you will probably need really good pair of side cutters or bolt cutters because the lines are steel., cut them then leave the area the gas isn't toxic but heaver than air and will displace it so if your around it you could suffocate

[Goats spudz]

use a Qev and blowgun mine is really reliable and very powerful at 70psi a nail will go through 2" of wood

[pneumaticcannons]

hey cool gun not much ive got to say other than get a threaded shrader valve(no epoxy) and bump up the pressure. Ive got a cheap $20 emergency car compressor that goes up to 300 psi. You should get a similar one instead of waisting time finding a fridge compressor.
Damage shots?

[jazzman56]

nathanhd123

I do have a safety net, i close the ball valve and set the pin in place. I then pressurize/load, then when i'm ready to fire i connect the spring the the ziptie.

Sorry to sound like an idiot but i've looked but still cannot find a brass or steel schrader valve anywhere, online or at a hardware store.

[Mr.Tallahassee]

A brass schrader should be with air fittings and compressor attachments. I bought one at my local hardware store.

[mattyzip77]

I also have a hard time finding good schraders. To get the one I wanted, I had to order from McMaster. Only ones I can find are dog poopie, the ones that are all rubber and sold at Wally World. Automotive stores in my area did not even have any good ones!!

[Mr.Tallahassee]

Automotive stores never have them because they aren't automotive parts. They're pneumatic parts(kinda obvious. I know ) and I found them at Ace Hardware down my street. Brass will hold up to a great deal of pressure. I've heard of them being tested over 2000PSI so they should easily hold up to 500PSI or so. This may be 1/8'' npt but it will do just fine. http://www.airridefittings.com/store/in ... ucts_id=24

[ookook]

A brass schrader should be with air fittings and compressor attachment