semi automatic- not that hard really. guide

[anarchy08]

hey,
so skulking around the background on the forums here for awhile and have seen some truly great works of manufacturing and the other side of the scale completely like coke bottle pneumatic's .
SO i thought id write up a short guide of how I achieved a reliable easy set up for a pneumatic rifle.

so for those struggling, most parts used were bought from ebay you just need to know what your looking for.
starting from the C02 bottle;
Ozito tank bunnings Aus
-300psi regulator (pressure regulator NOT flow reg.) ebay
High pressure quick disconect C02 rated -ebay
1/2'' Female > 6mm Male brass fitting - local plumbing store
Mechanical valve 5 port / 2 way (P-B) with A blocked to act as a 3/2 Normally open valve- ebay
6mm cap in A port -local plumbing store
1/2'' male> 6mm Male adapter-local plumbing store
1/2'' Quick exhaust port -ebay
1/2'' male> 3/4'' Male-local plumbing store
galv. 3/4'' F>F adapter
150mm 3/4'' galv threaded extender
3/4'' brass cap -as above plumbing store

should note BSP plumbing parts use strange sizing :S
6mm-12.7mm OD
1/2''-19mm OD
3/4''- 25mm OD
http://i1211.photobucket.com/albums/cc4 ... 222241.jpg

just in the prototyping stage at this point but it will be a cannon for a tank turret with semi auto function. the vent will trigger a fake blow back withdraw of the barrel and serve to act as a breach mechanism for the gravity fed magazine with each shot of the gun the breach sleeve will withdraw and allow the next shot to drop down.
the plan is to use old CO2 canisters, but the heads will need to be weighted for stability any ideas? was planning on drilling out and lead filling the fronts.

[wyz2285]

Not that hard? Just your co2 set up it´s going to be hard for most of the newbies. Regulated air source may seems simple to us who can refill them, but to those who are new with these things or have low cash it´s difficult, I remember when I started it took me a long time to get more than 100 psi. Also we all know the theory of semi auto with a 3-way and QEV, but I have seem a lot of people that can´t get a proper 3-way valve.
Back to your problem, the exhaust air exits in the same moment as the QEV opens, witch means the reloading will have to happen in the same moment as firing...

[anarchy08]

well yes, but most newbies are prompted to read before diving in, knowledge goes a long way in your design. you must agree that this is a very technical hobby, and as far as cash goes well you can get a QEV posted off ebay for less then 15 bucks. your going to spend more then that at the hardware store getting parts anyway :S
I was new here too, but reading helped me greatly rather then practical experience,I started with Dads air compressor @80 psi with pop off valve piloted, QEV design that worked well. Ultimately what we want is something portable in the end dont we? CO2 has the density that rewards the extra effort and funds
well yes it vents before the shot but yes i agree,
i was more thinking of using another small QEV attached A-NC and using the alternation of the valve to cycle the breach.
I really don't mean to have a go or anything, but if an Australian can get the parts anything is possible to newbies. Aussies here would know our struggle, shit laws.
big thx to JSR and poland spud for inspiration on the forums, just the two that come to mind that helped me learn here

[wyz2285]

but if an Australian can get the parts anything is possible to newbies. Aussies here would know our struggle, crap laws.

If it´s simple for you to get that co2 bottle refilled, then it´s better than Portugal. Don´t know why you Australians always make yourselfs such a martyr, you have ebay .au, bunnings... etc. At here I can not find a store that sells springs there is only one model of lathe for sell, no mill or what ever

[PaperNinja]

Can't you buy springs from mcmaster?

[dahakka]

if i have a co2 bottle , slide vavlve , qev ... it 's easy like Lego
hardest part is buy or make those stuff

[jonesy42]

@anarchy08... What parts are you looking for?
I live in australia too.

[pneumaticcannons]

but if an Australian can get the parts anything is possible to newbies. Aussies here would know our struggle, crap laws.

If it´s simple for you to get that co2 bottle refilled, then it´s better than Portugal. Don´t know why you Australians always make yourselfs such a martyr, you have ebay .au, bunnings... etc. At here I can not find a store that sells springs there is only one model of lathe for sell, no mill or what ever

Quit yo bitchin
You two at least live in a country that speaks your 1st language. I can't even communicate with the locals here. There's a reason my builds are almost always getto you know.
Man, now I'm the one bitchin'

[jonesy42]

You two at least live in a country that speaks your 1st language. I can't even communicate with the locals here. There's a reason my builds are almost always getto you know.
Man, now I'm the one bitchin' [/quote]


You can get what you need in australia,....if you got the Cash!

[anarchy08]

haha now thats what im talkin bout ! Jonesy nice job man, you got anymore details/pics? that things beautiful.
yeah this wasnt really a topic for bitchin that its hard to get stuff, its what you can build from what you can get.
jonesy is that chamber filled? little hard to get some details from the pic, but thats what im looking at building, rifle style clip fed bolt action, sodabulb rounds.
i need to upload a vid of my semi auto 6mm M16 then