Need advice- semi auto

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
Butch902
Private
Private
Posts: 19
Joined: Fri Oct 29, 2010 6:08 am

Tue Jan 04, 2011 9:07 am

Could someone give me some advice on what valve I would need to make my air gun semi auto?

I have a semi auto loading system just need a good valve to get 6 shots out of my 3'' chamber by 3 feet long at max 120 psi

please help
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Tue Jan 04, 2011 9:19 am

some questions for you to answer before any advice can be provided:

- what calibre/projectile is this for?

- what performance are you expecting in terms of projectile energy?

- what accuracy requirements do you have?

- what's your budget?

- what technical capabilities do you have?
hectmarr wrote:You have to make many weapons, because this field is long and short life
Butch902
Private
Private
Posts: 19
Joined: Fri Oct 29, 2010 6:08 am

Tue Jan 04, 2011 9:48 am

1.5 inch golf ball size

Performance: to shoot 50- 100 meters

fairly accuracy

Budget: alot

technical capabilties: i know how to use a metal lathe, weld, and operate other machines. e.g. mill's, grinder's
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Tue Jan 04, 2011 10:00 am

when you say shoot 50-100 metres, do you mean the projectile needs to reach that distance, or punch through say 3/4" of plywood at that distance?

3" by 3 feet at 120 psi is not a lot of air for 6 shots in a relatively large calibre.

Surely with a significant budget you can upgrade to a regulated paintball tank supply?
hectmarr wrote:You have to make many weapons, because this field is long and short life
Butch902
Private
Private
Posts: 19
Joined: Fri Oct 29, 2010 6:08 am

Tue Jan 04, 2011 10:11 am

for the golf ball to shoot 50 - 100m not go though anything

i can't get a paintball tank supply because to get a paintball tank filled you need a gun permit Class A in Aust also scuba tanks will not fill it because you need a scuba drivers permit then get the tank chack by them and then it can be filled.

to get the permits you need to go though alot of trouble and alot of time

any other tips/ help
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Tue Jan 04, 2011 10:21 am

Butch902 wrote:for the golf ball to shoot 50 - 100m not go though anything
In that case, a 3/4" Quick Exhaust Valve will do you fine.

There are various options for having such a valve operate semi automatically, here's one:

Image

In your case, the "regulated gas feed" would be connected to your air chamber.

A more efficient way of configuring it would be using a 3 way valve as a feed/pilot valve. This shuts off the air supply when the pilot is open, giving you better air economy which is a welcome benefit given your limited air capacity.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Butch902
Private
Private
Posts: 19
Joined: Fri Oct 29, 2010 6:08 am

Tue Jan 04, 2011 10:30 am

so pretty much put a regulator on my chamber then connect it to a 3 way valve then QEV? or reg then QEV? or i make 2 chambers 1 big the other smaller with a air/ gas reg in the middle which then would connect to a QEV and there my semi auto.

cuz i want a semi auto system that all i have to do is hit the trigger so i can shot my ammo every second no delay.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Tue Jan 04, 2011 4:02 pm

120 psi won't need regulating, that was just for the purposes of the diagram from a previous post.

You connect your chamber to the input of the 3 way valve, and one of the outputs to the QEV pilot - P in the diagram below. To R you connect your barrel/feed assembly, and to A you connect a small chamber, say 250-500mL should suffice for the distances you mentioned.

Image
i want a semi auto system that all i have to do is hit the trigger so i can shot my ammo every second no delay
The setup described should fire as fast as you can "pull the trigger", which in this case means switch outputs in the 3 way valve.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Crna Legija
First Sergeant 2
First Sergeant 2
Posts: 2333
Joined: Sun Jul 20, 2008 5:14 am
Location: australia

Tue Jan 04, 2011 9:05 pm

how about a argon tank for welding do you need a licence for them? also bunnings sells co2 tanks behind the checkout buy idk the thread on the tanks or if they will fit a reg
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
Butch902
Private
Private
Posts: 19
Joined: Fri Oct 29, 2010 6:08 am

Wed Jan 05, 2011 12:21 am

You might be onto somthing there -_-

You dont need a licence for argon welding tanks or to get them filled.


I will have to go to Bunnings and ask about the Co2 tanks but if they have any will they fill it or do i have to get it filled somewhere else?
User avatar
Crna Legija
First Sergeant 2
First Sergeant 2
Posts: 2333
Joined: Sun Jul 20, 2008 5:14 am
Location: australia

Wed Jan 05, 2011 3:09 am

they cant fill them

iv got to change my name it must be annoying typeing -_- :lol:
'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
Butch902
Private
Private
Posts: 19
Joined: Fri Oct 29, 2010 6:08 am

Wed Jan 05, 2011 3:11 am

dont know where i could get the tank filled then
User avatar
evilvet
Specialist 2
Specialist 2
Posts: 267
Joined: Sat May 01, 2010 2:48 am
Been thanked: 2 times

Wed Jan 05, 2011 5:16 am

Isn't there a general prohibition on feeding trolls?

"i can't get a paintball tank supply because to get a paintball tank filled you need a gun permit Class A in Aust also scuba tanks will not fill it because you need a scuba drivers permit then get the tank chack by them and then it can be filled. "

Yo gansta mofo bro, i be yur homie tun8t

Punctuation, grammar, lucidity.
Are these things too much to ask?

Yes it is late in the day, yes I am old, but please !!!!

And yes JSR you were right, Charles knew exactly what he was on about. Expanding population, finite supply of food, air and water, you do the math.
Post Reply