Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 49 users online :: 5 registered, 0 hidden and 44 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Exabot [Bot], Google [Bot], jimmy101, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Need help with semi auto, with tank.

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Need help with semi auto, with tank.

Unread postAuthor: glasklar » Thu Apr 14, 2011 3:06 pm

I'm new to pneumatic guns and just built a very simple before, so this time i where gonna go a bit further and build a semi auto rifle, I don't have a air compressor and i wouldn't like to use one as well since i would like to be able to shoot with my rifle in the forest. But i have some questions about the tank and the rifle itself. Will my rifle be semi or have i totally miscalculated it? its not in the right measurement but how small/big will my secondary tank have to be so i could get at least 5-10 shots(with partly the same speed) of before having to re-pump it?

Also feel free to comment anything you like


The rifles schematic: Image
  • 0


glasklar
Private
Private
 
Posts: 11
Joined: Thu Jul 05, 2007 7:17 pm
Reputation: 0

Unread postAuthor: POLAND_SPUD » Thu Apr 14, 2011 5:45 pm

you used pneumatic symbols... I wanna hug you :D (jk)

Will my rifle be semi
yeah, though you need a loading mechanism... I found that air cylinders work great when coupled with a 3 way valve

its not in the right measurement but how small/big will my secondary tank have to be so i could get at least 5-10 shots
I'd say that its volume has to be about 25 times larger than the chamber volume
  • 0

Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: ramses » Thu Apr 14, 2011 6:29 pm

You could also use a tank pressure higher than the pressure you want to use your cannon at. A simple air tool regulator would then take it down to some pressure, and velocity would be the same until the tank dipped below that set pressure. You do loose out on peak power( first shot) , though.

Have you considered a CO2 tank? ready made regulators for use with air tools are about $90.
  • 0

POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name :D
User avatar
ramses
Major General
Major General
 
Posts: 1679
Joined: Thu May 29, 2008 6:50 pm
Reputation: 3

Unread postAuthor: jackssmirkingrevenge » Fri Apr 15, 2011 1:22 am

POLAND_SPUD wrote:you used pneumatic symbols... I wanna hug you :D (jk)


No you're not, you genuinely want to hug him, I'm sure :D
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: Labtecpower » Fri Apr 15, 2011 2:36 am

According to fluidsim this should work.


Image
Image
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: glasklar » Fri Apr 15, 2011 3:21 am

I've been thinking about loading the rifle with 2 disposable CO2 cylinder and make some hot cover for them in the handle to make it look more realistic, do you guys know how i would calculate the size of my external tank for that? i also thought about making the external tank in a changeable size so i can either shoot a hole in a road sign with one shoot or use it in a paint-ball war and shoot 100 shots if u know what i mean, will that work like that? I find it hard to test since my only pneumatic spud gun is kind of simple and parts are expensive so id like to hear ideas from the pros before i waste my salary.

Thanks for the help everyone and Poland_spud I've seen your rifles, there way hot and i would hug you if i gotten the chance as well, but with "loading mechanism" do you mean something to load the air with or the bullets? I'm working on a bolt action with magazine and working ejector, hopefully it will work quite good, I will post more blueprints as soon as i can
  • 0


glasklar
Private
Private
 
Posts: 11
Joined: Thu Jul 05, 2007 7:17 pm
Reputation: 0

Unread postAuthor: POLAND_SPUD » Fri Apr 15, 2011 5:09 am

According to fluidsim
I wanna to hug both of ya :D

ohh notice that fluidsim has a symbol for QEVs (though you can't connect anything to its barrel port as it has an inbuilt muffler)...no need to use shuttle valve

ohh BTW I did use fluidsim to calculate/model that
its volume has to be about 25 times larger




with "loading mechanism" do you mean something to load the air with or the bullets


http://www.spudfiles.com/forums/files/s ... ii_400.gif

Bullets

i also thought about making the external tank in a changeable size
Just use threaded fittings and pipes

and parts are expensive
Not if you can reuse them (threaded fittings and pipes)

CO2 cylinder and make some hot cover for them in the handle to make it look more realistic, do you guys know how i would calculate the size of my external tank for that
You'd need a co2 calculator for that. IIRC Davidvaini has made one
  • 0

Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Sponsored

Sponsor
 


Unread postAuthor: jackssmirkingrevenge » Fri Apr 15, 2011 5:44 am

:D
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: Labtecpower » Fri Apr 15, 2011 5:54 am

how y'all like this?

Image

Image


semi auto reloading with mono-stable cylinder
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: al-xg » Fri Apr 15, 2011 6:24 am

I like the simple air ram connected to chamber with a 3/2 NO valve for piloting. You can use the same magazine behind QEV set up, as long as you make the air ram piston slightly larger than the barrel bore.


Err actually isn't there a slight issue on that last drawing, with the projectile loading and piloting starting at the same instant ?
  • 0

User avatar
al-xg
Colonel
Colonel
 
Posts: 643
Joined: Fri Jan 19, 2007 12:29 pm
Reputation: 0

Unread postAuthor: POLAND_SPUD » Fri Apr 15, 2011 6:32 am

Err actually isn't there a slight issue on that last drawing, with the projectile loading and piloting starting at the same instant
yes, you're right
I like the simple air ram connected to chamber with a 3/2 NO valve for piloting
me too.. no need to overcomplicate stuff and waste air
  • 0

Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: Labtecpower » Fri Apr 15, 2011 7:05 am

I saw some modifications have to be made :roll:
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: ecigar » Mon Apr 25, 2011 9:06 am

Got all, thanks!
  • 0

Enjoy your healthy smoking life: http://www.e-cigarette-supply.com

ecigar
Private
Private
 
Posts: 1
Joined: Mon Apr 25, 2011 8:37 am
Location: china
Reputation: 0

Return to Pneumatic Cannon Discussion

Who is online

Registered users: Bing [Bot], Exabot [Bot], Google [Bot], jimmy101, Yahoo [Bot]

Reputation System ©'