Design opinion for pneumatic

[Fish8myb8]

Hello and thanks for viewing.
I'v been thinking about making a new pneumatic to take the place of my old one.
I wanted to have:
-Something that can penetrate deep
-Something that can shoot more than once before it needs repumping
-Something that's somewhat aesthetically pleasing

I came up with this design.
Parts:
-1/2 copper pipe.....................Barrel
-1/2 repair pipe.......................breach loading
-1/2 male adapter....................connect barrel to nipple
-1/2 nipple..............................connect barrel to fitting
-1/2 to 3/4 fitting.....................connect barrel to QEV
-3/4 QEV from McMaster...........main valve
-3/4 to 1/2..............................connect QEV port to trigger
-1/2 to 1/4.............................QEv to trigger
-1/4 male adapter...................attach 1/4 45*
-1/4 45*.................................angle on the trigger
-1/4 male adapter...................45* to trigger
-1/4 trigger from McMaster.......pilot valve
-3/4 to 1/2..............................chamber tee
-1/2 male fitting.......................connect QEV to tee
-1/2 tee.................................splitting chambers
-1/2 ball valves.......x2.............let one chamber be open instead of 2
-1/2 45* elbows......x2.............move up chamber #1
-1/2 to 1 1/4...........x2...............enable fit to chamber
-1 1/4 chamber.......x2..............chamber
-1 1/4 end cap........x2............close off chamber


But that is pretty expensive, because of the two ball valves and all the reduction fittings. I couldn't find a 3/4 to 1/4 fitting, and I already have the barrel and trigger valve.
Please, suggest how I can improve on this, or a totally new design?


picturezzzzzzzz:

[clemsonguy1125]

It should work but you will loose pressure on each shot, since your going with copper you can use regulated co2, that will allow you to get rid of the large chamber and you will only need one ball valve,and the small chamber to hold the small amount of air for firing. Your get many more shots, it will be lighter, and more powerful

[Fish8myb8]

Thanks for the help.
Okay, I like that idea a lot. Ditch the big chamber and lightweight.
I'm a noob at this, would I have to buy he large paintball c02 tanks?
If I were to go c02, what diameter should the chamber be?

Edit:
I think c02 tanks are pretty expensive. I would like it to be self sufficient with my bike/shock pump. My bike pump goes up to 120, but I'v only gotten it to 100 only. If I were to get a shock pump, it should work well at 200-300 psi with a small 1/2 copper chamber, right?

[whitexnightjp]

you cant just buy the tank and plug it in you need to get a regulator to tone down the pressure in the co2 tank(which is expensive)and then a way to connect the tank and regulator to your gun. i don't fully understand the concept but i know thats what you have to do if you don't want an explosion

[Fish8myb8]

Yes I realize that from all the other c02 cannons on here. I'm on about a $50 budget, I don't want to be confined to c02. Would eliminating one chamber and making the other smaller and made of copper work of I were to buy a shock pump to get higher pressures than my bike pump?
Like a 1/2 by 12 inch copper chamber at 300-400 psi?

[iknowmy3tables]

you'd should defiantly use a regulator because other wise you will find massive pressure drops between shots unless your fill tank completely dwarfs the chammber

[Fish8myb8]

you'd should defiantly use a regulator because other wise you will find massive pressure drops between shots unless your fill tank completely dwarfs the chammber

I don't really like the idea of C02 anymore because of the dependability on it and the pricing of it all

[deathbyDWV]

May I suggest hammer valve? Or is that out of the question...

I think with a qev you won't be able to only partially empty a high pressure chamber. It won't be able to close fast enough...

[whitexnightjp]

you'd should defiantly use a regulator because other wise you will find massive pressure drops between shots unless your fill tank completely dwarfs the chammber

exactly right when you shoot your cannon a certain amount of pressure is released leaving a lesser pressure in your tank for example (im sure this ratio is wrong) if you had your tank at 100 psi when you shot it your tank would prob drop to 40psi so your second shot would be alot less powerful but with the two chambers you get two shots at the same psi just as long as you cut one off and use it for the second shot. but if your on a budget of only 50$ then i would look into some pvc(much cheaper) for your design. The shock pump and the small chamber would do well it just depends on the perjectile and you would have to pump it up after every shot

[Fish8myb8]

I'v made one recently actually, with a half-sphere bolt head on a soring closing against washer glued on the inside of a small pepsi bottle. I think I can scale it up and make one bigger, and with PVC. I'll give it a try. What type of valve is used in all the high-pressure launchers? in the 300-800 range? A home made piston?

edit:

I think I will stick with the QEV, shock pump, and a single chamber. This is my 2nd launcher, my first being a 1/2" pipe to a ball valve to a 2" pipe chamber.

My projectiles are nail darts. I would like to keep it simple for now, and maybe make a piston valve next for a challenge.

I do want this one to be full metal, though, so I am willing to wait and save on money if need be.

Should I just thread the shock pump extension into the chamber or have a schrader on the chamber?
I guess it depends on how I will be using the gun. I think I'll put a schrader on it since I have 2 that are rated to 250 psi. Mcmasters


Edit by MrCrowley: Please do not double post. Use the edit button instead.

[whitexnightjp]

i like the idea. If you have a shock pump you only need one chamber so that will cut your cost down.

[iknowmy3tables]

you'd should defiantly use a regulator because other wise you will find massive pressure drops between shots unless your fill tank completely dwarfs the chamber

I don't really like the idea of C02 anymore because of the dependability on it and the pricing of it all

I wasn't necessarily talking about CO2, just the use of a regulator in general

[spudtyrrant]

I'm on about a $50 budget

I'm sorry, but to be honest you couldn't build a pvc version of this for $50 let alone copper .

I wanted to have: -Something that can penetrate deep

and jack........ you are slacking

[DR]

If you're on a $50 budget, then why don't you consider purchasing <a href="http://www.blow-gun.com/storefront/merc ... =ULTRA-PRO" target="_blank">THIS</a>.

Multiple shot and requires <3psi to operate.

[jackssmirkingrevenge]

and jack........ you are slacking

Some of us work for a living hehe

With a bit of judicious use of proper epoxy this could easily be built on a budget, what many people don't realise about my launchers is that since I make almost no use of standard parts, at least ones which I actually pay for, the cost comes down a lot.

Take this one for example, if you factor in the cost of the pipe and epoxy and assume the schrader was ripped out of a used bicycle tyre, the total financial outlay was about $10

Epoxy FTW!