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 60 users online :: 4 registered, 0 hidden and 56 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

burst disc air gun

Built a pneumatic cannon? Then post it here! This section is for completed, finished cannons that you have built. Please include pictures and information.
Sponsored 
  • Author
    Message

burst disc air gun

Unread postAuthor: lasermaster3531 » Tue Jan 26, 2010 7:07 pm

This is my first air cannon to go on spudfiles, but it is not the first one I have made. This gun uses aluminum foil burst discs in a cascade-failure system with a blow gun pilot valve. the foil discs hold 20 psi each, and so far I have used two sets of three at a time for a total pressure of 100 psi. at 30 psi(two single discs) this thing will put a paper dart halfway into a cardboard box from 20 feet. it has a 1 1/2"x 15" sch40 PVC chamber, and a ~36" 1/2" sch40
CPVC barrel.
here it is.
Image

this is the valve pulled through the end cap.
Image

this is the main burst disc/blowgun assembly.
Image

this is a close-up of the barrel adapter. it is a 1" PVC slip/thread union with a 1" to 1/2" CPVC adapter hammered into it.
Image

here is one of the threaded unions unscrewed to show a blown burst disc prior to replacement.
Image

here is the whole assembly unscrewed and laid out. I got the two threaded unions from our dysfunctional sprinkler system for free, but they would be $13+ from a store.
Image

the whole thing cost me $25 or so to build, because I used so much"junk" from other projects. I recommend building one.
  • 0

Last edited by lasermaster3531 on Sun Jan 31, 2010 11:26 pm, edited 1 time in total.
User avatar
lasermaster3531
Private
Private
 
Posts: 5
Joined: Tue Jan 26, 2010 5:48 pm
Reputation: 0

Unread postAuthor: Lockednloaded » Tue Jan 26, 2010 7:43 pm

those are urls not img codes. But i looked at the pictures and seems to be a very cool little plinker. My burst disk gun is my favorite because of the simplicity. It almost never fails.
Good work on the triggered burst disks, i really like your set-up
P.s.
Your second disk is weaker that the first right (First from chamber)
  • 0

User avatar
Lockednloaded
Major General
Major General
 
Posts: 1558
Joined: Thu Sep 03, 2009 9:38 pm
Location: Texas, USA
Reputation: 0

Unread postAuthor: Marffy » Tue Jan 26, 2010 8:39 pm

looks cool. probably would be a good cannon for airsoft. Try any nail darts?

EDIT: i got a good idea, put the bbs in between the 2 burst disks.
  • 0

Last edited by Marffy on Tue Jan 26, 2010 10:36 pm, edited 1 time in total.
"Hard work has a future pay-off. Laziness pays off now."
User avatar
Marffy
1st Lieutenant
1st Lieutenant
 
Posts: 258
Joined: Mon Jul 27, 2009 2:03 pm
Location: earth
Reputation: 0

Unread postAuthor: inonickname » Tue Jan 26, 2010 10:24 pm

Your second disk is weaker that the first right (First from chamber)

It's meant to be. The disks are tirggered by exhausting the gas between them, allowing the first disk to rupture (higher differential force) and then the second to rupture (as it is weaker).

probably would be a good cannon for airsoft. Try any nail darts?

Lol.

Kepp it up :wink:
  • 0

PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
inonickname
Lieutenant General
Lieutenant General
 
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Unread postAuthor: lasermaster3531 » Thu Jan 28, 2010 10:15 pm

the burst discs are the same. the space between the discs is pressurized to half that of the main chamber. when you exhaust the space between them(lowering the pressure), the rear one blows first, then the front one. there is a page on the spudfiles wiki.
  • 0

User avatar
lasermaster3531
Private
Private
 
Posts: 5
Joined: Tue Jan 26, 2010 5:48 pm
Reputation: 0

Unread postAuthor: Lockednloaded » Thu Jan 28, 2010 10:50 pm

I know, I have seen the wiki, and done quite abit of research on triggered burst disks. The second disk is actually supposed to be weaker, barely strong enough to hold the pilot volume this way air releases immediately into your chamber instead of all venting out of your exhaust valve
  • 0

User avatar
Lockednloaded
Major General
Major General
 
Posts: 1558
Joined: Thu Sep 03, 2009 9:38 pm
Location: Texas, USA
Reputation: 0

Unread postAuthor: lasermaster3531 » Fri Jan 29, 2010 8:38 pm

mine has them the same, but all of it goes out the barrel. the blow gun has such a small hole that it only lets through a small amount. this is helpful when the barrel becomes blocked or clogged, because the air will just go through the blow gun in a slow(ish) manner.
the burst discs in a triggered burst disc system are supposed to be the same pressure rating. here is a quote from the spudfiles wiki.
"The burst disks must be dimensioned to break somewhere between half and full chamber pressure. The trigger chamber is filled to half the chamber pressure, and then the chamber is filled to full pressure."
that means that both burst discs are rated at X psi. the space between them is at a little less than X psi, and the air tank is at a little less than 2X psi.
I don't understand how to put photos on here. can you help me?
what do you mean by img codes, i thought that you were supposed to put in the url of the photo at a photo sharing site. :wink:
  • 0

User avatar
lasermaster3531
Private
Private
 
Posts: 5
Joined: Tue Jan 26, 2010 5:48 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: McCoytheGreater » Fri Jan 29, 2010 9:08 pm

Pretty nifty gun you have. I really like the way these burst disk air guns work. Have you experimented with different layers on the burst disks to up the pressure in the chamber, or would there be too many variables to have to work out? I've never made a burst disc type gun, but would love to give it a try. They seem fairly easy. What's the difference in velocity versus a piston/sprinkler type gun?
  • 0

User avatar
McCoytheGreater
Sergeant Major
Sergeant Major
 
Posts: 191
Joined: Tue Dec 15, 2009 1:10 am
Location: Mississippi State
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Sat Jan 30, 2010 3:43 am

Image

Image

Image

Copy the image locaction and put that between [img] codes ;)

Nice build, well made and with a bit more pressure probably capable of some very impressive damage.

They seem fairly easy. What's the difference in velocity versus a piston/sprinkler type gun?


Burst disk valves are probably the easiest and most effective valves to build in terms of performance. You effectively have a valve opening time of zero, instantaneous maximum flow, have a play with GGDT and you'll see the difference it makes ;)
  • 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: Ragnarok » Sat Jan 30, 2010 6:36 am

jackssmirkingrevenge wrote:... instantaneous maximum flow ...

Although the nature of that flow depends somewhat on how the disk blows. If it fails from the centre, then it folds outwards - and that can then inhibit flow around the edges.
If it fails around the edge, then the centre gets blasted out down the barrel, which can either damage the projectile or hinder flow around the fragments of disk in the air flow.

Burst disk valves are not quite as perfect for performance as some people would like to believe.

Ironically, the best option you can really have is a ball valve, provided you can find a way to open it in less than about a millisecond.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: lasermaster3531 » Sat Jan 30, 2010 5:19 pm

jackssmirkingrevenge, I tried to copy the image location, but I don't know how to do it. I know you all must think I am an idiot, but I am just new at this. I have right clicked on the photo, but there isn't an option that says "copy image location". there is one that says "view page source", one that says "copy image URL", and one that says "save image as...". I am new at this, so please don't call me stupid or anything. I am really smart(and modest,too!), but I don't see it.

PS.to all the people that asked about power, I have tried it with 3 burst discs in each holder at a total if 100psi, and this thing can hurl a paper cone dart about half a mile or more. once I tried a cone dart without any reinforcement like extra tape on the back end, and it just shredded the dart.
  • 0

User avatar
lasermaster3531
Private
Private
 
Posts: 5
Joined: Tue Jan 26, 2010 5:48 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Sun Jan 31, 2010 3:34 am

lasermaster3531 wrote:one that says "copy image URL"


This is the one you want ;)

Then post as follows [img]image%20url[/img]
  • 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: lasermaster3531 » Sun Jan 31, 2010 11:02 pm

thanks! I will fix it right away. :D
  • 0

User avatar
lasermaster3531
Private
Private
 
Posts: 5
Joined: Tue Jan 26, 2010 5:48 pm
Reputation: 0

Unread postAuthor: Lockednloaded » Sat Mar 20, 2010 6:44 pm

I have tried it with 3 burst discs in each holder at a total if 100psi, and this thing can hurl a paper cone dart about half a mile or more.

That is highly unlikely, the 1/2 mile claim is often times made by those with bad guessing skills, or those who greatly over exaggerate performance. Unless you have a video or a ggdt file to back this up, don't say it. But again, great cannon.
  • 0

I love lamp
User avatar
Lockednloaded
Major General
Major General
 
Posts: 1558
Joined: Thu Sep 03, 2009 9:38 pm
Location: Texas, USA
Reputation: 0

Return to Pneumatic Cannon Database

Who is online

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

Reputation System ©'