SpudFiles

I'm moving forward slowly but steadily with this, but I've never really documented a build of anything before, so bare with me and my crappy photography.

This is still in a very early stage, only the valve body and the connection between the tank and it are even started.
I'm in for the long haul with this one.

Also, if anyone in the Uk wants some machining/to get rid of any old tooling done, I can offer my amateur services, just pm me.

hey nice job, where is the bolt in this bolt action rifle? nice job with the milling. not many people on spudfiles ever uses machine work on there guns

Looking good so far.

you should add "Build Log" to the title, so every one knows what to expect.

Looks good. Also same as above. What part is this exactly?

Wow I didn't know anything about rotary tables until I saw this post. That looks like an extremely useful accessory to a milling machine. Excellent work, and good for you having a setup like that. You make most of use jealous.

OK, so I've done some math.

I was planning a hammer valve, but unfortunately I just figured out that if the valve stem had a radius of 3mm, (Diam=6mm) then a pressure of 400psi (0.28123 kg/mm2) would exert 7.95kg.

To clarify; 0.2812 (3^2 pi) = ~8kg

8kg is too much force for as small a hammer as I had planned, I think, and a bigger one isn't an option.

The goal is to have a small repeating valve (one pull of the trigger does not discharge the whole tank, cock, fire again etc.)

To that aim I did some modeling of another possible valve design, but I am not sure how well I can make internal O-ring grooves. If anyone has had any experience making them, I'd really like to know how it went.

Has anyone made a valve like this before? Any comments and ideas are welcome, this is certainly not final.

Make O-rings?? now theres an idea!

O-ring grooves then, if you wanna get picky.

It's quite easy to make o-rings, there are tutorials on the web.

I've had a quick look, but couldn't find much comprehensible advice.

Here's the part I think will cause me difficulty in terms of getting it to seal

Xerxys wrote:I've had a quick look, but couldn't find much comprehensible advice.

Machinery's Handbook is where you'll find what you're looking for.

That's your side of the pond, but still, 83$ for a book? That's quite a bit.

cough cough click here cough cough

No hobby/machine shop is complete without at least one copy of Machinery's Handbook.

Pure gold.

If you don't want to bore the o-ring grooves, you could machine sleeves that sandwhich the o-rings. I've seen more than one spool valve cunstructed in such a manner.

http://www.bruininstruments.ab.ca/PrintablePDF/G1F.pdf

See pg 18 Pilot assembly.

with your ability to machine parts, you could go with a pneumatic ram powering a piston like in a spring airgun. if it is going to be bolt action, it may as well be spring powered