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 77 users online :: 5 registered, 0 hidden and 72 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Air piston bb gun hybrid

This area is for the discussion of BB or airsoft sub machine guns, and or other small arms such as pellets.
Sponsored 
  • Author
    Message

Air piston bb gun hybrid

Unread postAuthor: Sticky_Tape » Sat Dec 20, 2008 10:44 am

This is an Idea I thought of while looking at some pipe and my 4.5mm barrel. Using air to accelerate a piston to compress air to fire a bb. basicly the air replaces a spring. I heard once that if you accelerate a 1/2'' piston at 7fps you coulds get a bb past the sound barreier with a x lenth of barrel. tell me what you think
IF ANYBODY WAN"T TO USE THIS IDEA THEY CAN BUT JUST GIVE ME SOME CREDIT OK?
  • 0

Attachments
Untitled.jpg
Untitled.jpg (30.8 KiB) Viewed 1419 times
Last edited by Sticky_Tape on Sat Dec 20, 2008 11:29 am, edited 1 time in total.
You can tell how awesome a cannon is by the pressure used.
http://www.spudfiles.com/forums/high-pr ... 12803.html
xnt rnm ne z ahtbg
User avatar
Sticky_Tape
Brigadier General
Brigadier General
 
Posts: 1175
Joined: Thu Jan 31, 2008 6:35 pm
Location: Sydney, Nova Scotia, Canada.
Reputation: 0

Unread postAuthor: VH_man » Sat Dec 20, 2008 10:49 am

Kinda like a Light gas gun.....

It would work better, Actually, If your piston was simply accelerated like a normal projectile... AKA, screw the holes.

And fill the space between the BB/pellet with some kind of light gas, like helium. It will work far better.

I EXPECT some > 1000 FPS figures!
  • 0

User avatar
VH_man
Major General
Major General
 
Posts: 1827
Joined: Sat Dec 09, 2006 6:00 pm
Location: New Hampshire
Reputation: 1

Unread postAuthor: Fnord » Sat Dec 20, 2008 10:59 am

I'm guessing if the bb is loose in the barrel it will start to move before the piston ever covers the holes. Air behaves differently than you might expect sometimes. Add an oring in the barrel to keep the bb snug until the pressure rises a bit.
  • 0

Image
User avatar
Fnord
Major General
Major General
 
Posts: 2244
Joined: Tue Feb 13, 2007 9:20 pm
Location: Pripyat
Reputation: 7

Unread postAuthor: Sticky_Tape » Sat Dec 20, 2008 11:01 am

The holes are so that the piston accelerates with out compressing any gas making that piston have greater inertia to compress the air very quickly once the front of the piston passed the holes.
EDIT: I think it would be better to have a powerful magnet next to where the bb would be in the barrel
  • 0

You can tell how awesome a cannon is by the pressure used.
http://www.spudfiles.com/forums/high-pr ... 12803.html
xnt rnm ne z ahtbg
User avatar
Sticky_Tape
Brigadier General
Brigadier General
 
Posts: 1175
Joined: Thu Jan 31, 2008 6:35 pm
Location: Sydney, Nova Scotia, Canada.
Reputation: 0

Unread postAuthor: john bunsenburner » Sat Dec 20, 2008 11:20 am

How about using a balsa piston which replace after each shot and using helium,i like the idea of the O-ring rather than the magnet because one the BBis out of the O-ring it is now affected by it while if oyu have a magnet it could still some how affect the bb in some way or another.
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Unread postAuthor: Sticky_Tape » Sat Dec 20, 2008 11:25 am

Using a balsa piston wouldn't allow the air to be compressed very affectively due to the low mass to volume ratio. I don't like the idea of having to change the piston every shot that would be like burst disks. I waqn't to use a magnet because I think a o-ring would have to be replaced after so many shots.
  • 0

You can tell how awesome a cannon is by the pressure used.
http://www.spudfiles.com/forums/high-pr ... 12803.html
xnt rnm ne z ahtbg
User avatar
Sticky_Tape
Brigadier General
Brigadier General
 
Posts: 1175
Joined: Thu Jan 31, 2008 6:35 pm
Location: Sydney, Nova Scotia, Canada.
Reputation: 0

Unread postAuthor: john bunsenburner » Sat Dec 20, 2008 11:30 am

I just have the feeling that any piston will be smashed to smitherines and thus unding a piston that is cheep and will be replaced any how will be a good idea...

And i guess the magnet will be ok, doubt it ould do anything major, though i still prefer O-rings, its your gun not mine!
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: CpTn_lAw » Sat Dec 20, 2008 11:56 am

make an aluminium piston, with a plastic seal. Fill in the space between th piston head and the barrel with a stoechiometric mix of air and gas, and use the diesel effect to make an explosion inside(for above atm pressure mixes, use a burst disc). The o-ring idea is a great one. It will give a verygood compression and when the pressure is too high, the rubber will compress and let the BB fire. It is the principle of air rifles though, nothing really new. + you need to play with the venturi effet, and have a very little bore compared to the chamber.
  • 0

"J'mets mes pieds où j'veux, et c'est souvent dans la gueule."
User avatar
CpTn_lAw
Brigadier General
Brigadier General
 
Posts: 987
Joined: Sun Sep 11, 2005 9:10 am
Location: France
Reputation: 0

Unread postAuthor: Sticky_Tape » Sat Dec 20, 2008 11:58 am

Well if I could have it heavily padded I think I could make it last at least 50 shots which would be better than 1 and it would have alot better power because of it's weight.EDIT: I do not wan't to use any fuels or burst disks I wan't to make it a pure pneumatic.
  • 0

You can tell how awesome a cannon is by the pressure used.
http://www.spudfiles.com/forums/high-pr ... 12803.html
xnt rnm ne z ahtbg
User avatar
Sticky_Tape
Brigadier General
Brigadier General
 
Posts: 1175
Joined: Thu Jan 31, 2008 6:35 pm
Location: Sydney, Nova Scotia, Canada.
Reputation: 0

Unread postAuthor: newbmatic » Sat Dec 20, 2008 2:00 pm

Maybe you could have a burst disk, but instead the piston could have a needle or something on its head.idk. Great ideea though. Good luck!
  • 0


newbmatic
Private First Class
Private First Class
 
Posts: 34
Joined: Sun Jul 13, 2008 5:17 pm
Reputation: 0

Unread postAuthor: ALIHISGREAT » Sat Dec 20, 2008 2:05 pm

i like the idea, but what kind of piston run-up length do you envisage and how long would the compression chamber be?
  • 0

<a href="http://www.bungie.net/stats/halo3/default.aspx?player=ALI H IS GREAT"><img src="http://www.bungie.net/card/halo3/ALI H IS GREAT.ashx"></a>
Image
User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: Gippeto » Sat Dec 20, 2008 2:33 pm

Sticky, I think it'll work, you're making it harder, but not impossible.

I would leave the tube intact. The pressure accelerating the piston will keep doing so until the pressure is equal on both sides, and then it will help offset the deceleration force of the high pressure side.

This combined with the momentum of the piston, should give you a substantial pressure boost.

IF you can prevent the bb from moving before the pressure gets high.

The o-ring referred to, may be your ticket to success.

Or try a burst disk. :wink:
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: Sticky_Tape » Sat Dec 20, 2008 2:52 pm

The holes in the pipe are so that I don't need to use a burst disk or an oring. I think this will give a beter pressure boost because the holes in the pipe allow the piston to accelerate quicker because there wouldn't be pressure building at the front of the piston and by making the piston heavier it will compress the air quicker. the compression chamber will be 3'' long and the lenth to accelerate the piston will be 7 1/4'' there was a change in plan I am going to use 3/4'' cpvc.
  • 0

You can tell how awesome a cannon is by the pressure used.
http://www.spudfiles.com/forums/high-pr ... 12803.html
xnt rnm ne z ahtbg
User avatar
Sticky_Tape
Brigadier General
Brigadier General
 
Posts: 1175
Joined: Thu Jan 31, 2008 6:35 pm
Location: Sydney, Nova Scotia, Canada.
Reputation: 0

Unread postAuthor: VH_man » Sat Dec 20, 2008 3:00 pm

I feel still, Very strongly, in fact, that the need for the holes is null.

take a look at Light Gas Guns, Which are used in physics labs to fire projectiles at 3000-4000 FPS. So fast, In fact, that theyre finding F=MA does not apply to all situations.....

Image

Just replace the Gunpowder with an Air cannon and we have exasctly what you have described.
  • 0

User avatar
VH_man
Major General
Major General
 
Posts: 1827
Joined: Sat Dec 09, 2006 6:00 pm
Location: New Hampshire
Reputation: 1

Unread postAuthor: john bunsenburner » Sat Dec 20, 2008 3:04 pm

There is one trouble i see in your meathod: It will be hard to fill the compression chmber with only h2, and a mix od h2 and air will definately ignite under such presures...Use He
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Next

Return to BB/Airsoft/Pellet Gun Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'