Converting Oxygen Cylinder

[BoyntonStu]

This is a converted 66 cu in M6 Aluminum cylinder.

It weighs about 2 pounds.

It was a challenge to tap a 1/2" pipe thread into it.

I twisted the cylinder with a homemade strap wrench while the tap was held fixed in a vice.

No drilling, just forced it through the existing threads.

It took about 20 cycles of in out turning to get it done.

A 1/2" > 1/4" bushing and it was finished.

I can pump it up to 700 psi in 80 seconds.

No leaks.

The Trom-Boyn chamber uses 50 psi per shot.

It is a 6 shooter to 400 psi.

I haven't maxed out the compressor because I am afraid of messing up a good thing.

[FighterAce]

Pretty nice  I guess its a good thing to have when you're shooting in your backyard so you dont have to keep filling after each shot. It would be a pain to carry in the field tough.. a 6 pound rifle and a house on my back is enough even for me 

Are we gonna see a video from your soon?  I'd really like to see how this thing can speed up the rof

[username1]

What semi-automatic mechanism are you going to make, BoyntonStu? Is that regulated?

[BoyntonStu]

What semi-automatic mechanism are you going to make, BoyntonStu? Is that regulated?

Not regulated, however starting with 750 psi and regulating to 500 psi would give 5 shots at 500 psi.

A constant 500 psi would be a good thing.

Hmmn, another project.

The Trom-Boyn chamber size reduces the oxygen bottle pressure 50 psi for each shot.

The Lewis and Clark air rifle was a hammer valve and not regulated.

Our editor showed us a way to fill a small 'firing' chamber for a repeater.

With pneumatics, you have 2 choices, regulate or not.

As for government, I prefer less regulation.

[username1]

Do you mean the system that needs a secondary chamber and a ball valve to open and shut for each shot? That's the simplest unregulated multi-shot set-up. I think hammer valve is a good regulated system itself.

[BoyntonStu]

Do you mean the system that needs a secondary chamber and a ball valve to open and shut for each shot? That's the simplest unregulated multi-shot set-up. I think hammer valve is a good regulated system itself.

Do you mean the system that needs a secondary chamber and a ball valve to open and shut for each shot?  Yes.

Both systems are unregulated.

The hammer valve allows full chamber pressure into the barrel.  (Lewis and Clark's rifles)

[Forum Admin]

As for government, I prefer less regulation

We think alike. 

To get a simple hammer valve to work as a regulated system requires a lot of spring tweaking and only works well over a narrow pressure range. There are a lot more elaborate hammer valve configurations that high end manufacturers use to get better shot consistency, but they tend to be quite expensive.

A simple way to regulate a two chamber homemade airgun is to put a needle valve between the shut off valve and the airgun. This limits flow to give you time to close off the fill valve when it reaches a desired pressure. This of course requires you to have a pressure gauge on the firing chamber.

[username1]

Has anyone here ever made or heard of homemade regulator, especially PVC one? I can't find much information using Google :-(

[Forum Admin]

I just took apart a cheap regulator that I bought from Harbor Freight years ago. It appears to be more of a flow limiter than a true regulator, though, as there is no spring inside it. 

[BoyntonStu]

I just took apart a cheap regulator that I bought from Harbor Freight years ago. It appears to be more of a flow limiter than a true regulator, though, as there is no spring inside it. 

If you fill a firing chamber with a 1/4" BV can it be used slightly cracked open to control the flow/pressure?

[Forum Admin]

Yes, you sure can, that's what I did on my air pack video on youtube. It fills the gun to full system pressure in the time it takes to reload (a couple of seconds for the particular airgun used).