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Pneumatic Design

Posted: Mon Sep 10, 2012 11:46 am
by HarriDawwg
Hey im pretty new, joined i while ago but have really been very active :S
Anywho, this is a pic of what im planning to do but just wondering if its logical and reasonable to make?
Any help would be appreciated greatly :)
Sorry for the poo drawing :p and yes i spelt barrel wrong also schrader valve not labeled but between qev and blowg -_-

Thanks
HD

Posted: Mon Sep 10, 2012 12:23 pm
by 8tonsemi
I like the design except for the hose that will reduce air flow causing it to less powerful. And Is the air tank going to be a soda bottle?

Posted: Mon Sep 10, 2012 4:25 pm
by Gippeto
8ton....the hose is the reservoir (firing chamber). :wink:

Would personally prefer that to be made of metal (suitable tubing or pipe and fittings), but otherwise no real issues with it.

Posted: Mon Sep 10, 2012 4:57 pm
by wyz2285
Gippeto wrote:8ton....the hose is the reservoir (firing chamber). :wink:

Would personally prefer that to be made of metal (suitable tubing or pipe and fittings), but otherwise no real issues with it.
There is a problem, from the position of the fill port, it's a unmodified QEV. And that means he can't refill the secondary chamber from the chamber side. Drill a 2 mm hole on the QEV's piston and add a light spring behind it will solve this problem.
If his main chamber it's soda bottle, there is no need to use metal fittings for it.

Posted: Mon Sep 10, 2012 9:56 pm
by HarriDawwg
Awesome Thanks for all the input :D
Okay so how about modded QEV, then instead of blowgun i put like a air safety release valve straight onto the QEV?
Then i can fill from another port such as putting a schrader valve on the tank? :3

Re: Pneumatic Design

Posted: Tue Sep 11, 2012 1:01 am
by jackssmirkingrevenge
HarriDawwg wrote:Sorry for the poo drawing
It's not that scatological :)

http://www.spudfiles.com/forums/semi-au ... 23626.html

Posted: Tue Sep 11, 2012 1:41 am
by HarriDawwg
jackssmirkingrevenge thanks for the link, are those qevs easily available?

With the slide valve, could i swap it out for like a safety release but so it doesn't release itself? so i can use a triger and isnt like an auto, like a schrader valve with and end cap to release pressure and act as the pilot?

Here is another design i was thinking with a bike pump attached, constructive criticism would be appreciated.

Thanks

HD

Posted: Mon Sep 17, 2012 9:55 am
by HarriDawwg

Posted: Mon Sep 17, 2012 12:11 pm
by jonesy42
HarriDawwg wrote:jackssmirkingrevenge thanks for the link, are those qevs easily available?

With the slide valve, could i swap it out for like a safety release but so it doesn't release itself? so i can use a triger and isnt like an auto, like a schrader valve with and end cap to release pressure and act as the pilot?

Here is another design i was thinking with a bike pump attached, constructive criticism would be appreciated.

Thanks

HD

Hi, you can get cheap qev valves and 3 way trigger valves here:
(look under industrial equipment/tools, then pneumatics) @ http://www.uxcell.com/
Or just search "quick exhaust valves" on ebay.

Posted: Mon Sep 17, 2012 8:29 pm
by HarriDawwg
jonesy42 wrote:
HarriDawwg wrote:jackssmirkingrevenge thanks for the link, are those qevs easily available?

With the slide valve, could i swap it out for like a safety release but so it doesn't release itself? so i can use a triger and isnt like an auto, like a schrader valve with and end cap to release pressure and act as the pilot?

Here is another design i was thinking with a bike pump attached, constructive criticism would be appreciated.

Thanks

HD

Hi, you can get cheap qev valves and 3 way trigger valves here:
(look under industrial equipment/tools, then pneumatics) @ http://www.uxcell.com/
Or just search "quick exhaust valves" on ebay.
Awesome thanks jonesy42 :) what you you think about the design?
The barrel inside dia is 7mm so custom ammo and bbs, there is no chamber in the second drawing i was thinking of using the pump as the chamber, do you think this will be enough or should i fit in a elbow to increase it?

Posted: Tue Sep 18, 2012 1:44 am
by jonesy42
@harridawwg.... Nice, looks a bit like a Air Force Talon , in the drawing with air tank in the stock).......
Im not sure what you mean with the pump etc though?
Here are some photos of the main parts i use for my semi-auto qev rifles.
I use a 6mm barrell and 9.5mm.

Posted: Tue Sep 18, 2012 4:23 am
by jonesy42
All comes down to how much coin is in your pocket really.
If you are making your own stock, it would cost around $250
to buy these other parts/fittings
including scope, paintball tank etc.
Well worth it when the finished product performs as good or better than a
commercial factory air rifle in my opinion...All i need now is a RIFLED BARREL!,...yay :D

Posted: Tue Sep 18, 2012 12:30 pm
by HarriDawwg
Awesome thanks so much jonesy42 :D

With the pump in the second pic would be the chamber per say but i highly doubt its big enough, so i was thinking an elbow would allow enough space?

Posted: Tue Sep 18, 2012 7:58 pm
by jonesy42
HarriDawwg wrote:Awesome thanks so much jonesy42 :D

With the pump in the second pic would be the chamber per say but i highly doubt its big enough, so i was thinking an elbow would allow enough space?

Is that a bike "shock pump" you want to fit in your forestock?
I am not familar with how they work, but im sure someone could
give you some advice on whether your theory would work or not.
Would you not have to pump it up after every shot though? Sounds
annoying to me lol!... Have you thought about running it with C02?
You could put a small c02 bottle in your forestock instead, then you
at least get a few shots out of it without having to pump it up after every
shot.

Posted: Wed Sep 19, 2012 10:49 am
by HarriDawwg
True True, i was thinking it wouldn't be to bad as it would be a small chamber therefore not to much effort to pump it, but a bigger chamber or using co2 would be better.
Using a butterfly valve would suffice to use it for multiple shots hmm design rethink i think ;P
Thanks Jonesy :)