Piston Handgun Design

[shadowzzz]

Hello,

I am planning on making my first piston gun, and decided that it will be a handgun.

This is the design thus far:



The barrel is 15mm OD and the chamber parts are 22mm OD.
I will make a detachable bb-barrel for it, if I can find one...

Well, do you see any design flaws or can you think of some improvements ?
Will the vertical chamber part do any good ? I thought it would come in handy because it doubles as grip.

Please tell me what you think of it !

[Carlman]

yea mate should be sweet, i had a coax 15mmx20mm and it worked fine, yours is the same just with a bit extra chamber because of the T.

You wont need the spring unless you fill via chamber though.

[shadowzzz]

Oh, but I am filling via the chamber, via the little vertical piece.
I read somewhere on this marvelous site that that's alot faster than waiting for air to leak and equalize from the pilot space to the chamber ?

Is it very difficult to fill via the chamber?

[sniper hero]

filling via pilot side doesn't take longer in this design maybe 1sec and because of the spring you lose a little power and it might be the case it takes some time before it seals.

I would go for a blowgun with a male cuick connect screwed in it
and yes you have to hold the blowgun while filling.
ps: no spring needed then

[john bunsenburner]

Hmm, the design is simple, and should work(if you leave the spring out and fill via pilot side it will work great) but the blow gun is in a really wierd position in tems of looks...

If you are going more for power than looks this is great, if not then try this(its new, its random, but hey, what else woudl you expect from me). I think the diagram makes sense on its own(that is if you manage to read my writing) if not, feel free to ask.

[MRR]

Consider to pressurize from the pilot volume (with a small chamber like in a pistol it wouldn't make any difference).

Coaxial are bad designs to go semi / auto so there wouldn't be an advantage either.

[MRR]

After writing the comment on this post I ate something, drank a coffee and then I build a coax with spare parts laying around.
All in about one hour .

Well I already had a piston and I didn't make a barrel support but it works like a charm.
Not bad for a first try on a coax I think.

Length: 99cm (including blow gun)
Chamber: 1", 40 cm long
Barrel: 15mm, 78cm long



This is no pistol but a really easy build that you could adapt in a smaller scale.

[shadowzzz]

Wow, nice build there! It's very similar to what I was thinking of, but I think I'll make mine shorter.

You are not filling from the pilot side are you ? Do you have a spring or something ?

by the way: is it possible to hook up a schrader ( or smaller bike valve ) and a blowgun to the same endcap ? if not, I think I'll decide not to fill from the pilot side, al that tinkering with male quick connects...
I think I can't find those here in Holland..

If I understand correctly: A quick connect is used so you can also fill via the blowgun, right ? If not, what is it for ?

Again, cool gun MRR !

Edit: Why do you have a ballvalve between your chamber and your schrader ? Anti-leakage or something ?

[twizi]

why not do somethin like the high presure pistol idea go to search and type it in
it looks like it works well try this idea it also the simpilest idea

[Gippeto]

by the way: is it possible to hook up a schrader ( or smaller bike valve ) and a blowgun to the same endcap ?

Use a tee, like in the picture below.

[Carlman]

Search for TG6 on spudfiles. Its a qev gun I made where the pilot/fill was a 1/4" ball valve and a de cored scrader in the end of it. I opened the BV filled through scrader closed BV then unhooked air hose then used BV as pilot valve.

I would have linked you but I am posting from my phone.

It worked flawlessly as a pilot setup.

[LCTChamp]

If I understand correctly: A quick connect is used so you can also fill via the blowgun, right ? If not, what is it for ? Razz

No. A quick connect is just another way to fill up the gun. Most compressors have a female quick connect on them already, so they use these to fill instead of using a shcrader valve.

Edit: Why do you have a ballvalve between your chamber and your schrader ? Anti-leakage or something?

There isn't a schrader valve there. It is a quick disconnect. Shrader valve's have a built it valve to stop air from coming back out. There is no valve inside of a quick disconnect that prevents air from coming out. So he added a ball valve.

[shadowzzz]

Oh okay, thanks for the major clarifictations, all!

Oh and Gipetto, I thought of that too but I thought the increased pilot volume might be a very bad thing for a small gun, like my design-thingy.
But if it doesn't matter alot, I'll do what you suggested!

Thanks all, sorry to bother you all.

[SubsonicSpud]

If you want to make it more pistol like, I would ditch the tee section and keep it as a simple coax. The blow valve can be attach to the back via a 45 or 90 degree elbow, and a grip can formed around the blow valve. This will give you a pistol style L shape that can be shot single handed.