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 73 users online :: 5 registered, 0 hidden and 68 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

Another hybrid cartridge prototype

Post questions and info about hybrid (compressed gas with fuel) powered cannons here. This includes discussion about fuels, ratios, ignition systems, build types, safety, and anything else relevant.
Sponsored 
  • Author
    Message

Another hybrid cartridge prototype

Unread postAuthor: spudamine » Tue Aug 31, 2010 3:56 pm

here's another hybrid cartrige concept, based on JSR's work but a bit different:
Image
The top part is the cartridge, just a piece of 28mm copper with a schrader and a 'hook' epoxied into one end. The hook forms one side of the spark gap and is also an attachment point for the breakable link.

Image

The bottom half is the projectile which is a 1/2" iron nipple glued into a section of aluminium pipe, there is an o-ring on the back and a rod through the middle. A loop of cord or wire (the breakable link) is tied around this rod, the two halves are fitted together and a twist secures the breakable link under the hook.

the following vid is a pneumatic test using some quite strong cord as a breakable link, it proved to be too strong and I had to twist it around before it blew at about 150-200psi.

[youtube]http://www.youtube.com/watch?v=epj-9sPeDEk[/youtube]

despite only having about 2" of barrell I managed to stick the projectile into the concrete wall :D

Image

unfortunately the recoiling cartridge ended up on the floor with a dent in it, copper in not ideal for this I will use a thicker aluminium tube for the next one. I'm also going to experiment with some different materials for the breakable link before moving onto a 5x mix test.
any comments or suggestions welcome
  • 0

User avatar
spudamine
Sergeant Major
Sergeant Major
 
Posts: 184
Joined: Sun Nov 23, 2008 2:47 pm
Reputation: 0

Unread postAuthor: Gun Freak » Tue Aug 31, 2010 4:41 pm

Well this is certainly a new concept. I am looking forward for updates. How much pressure was the input?
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Unread postAuthor: jackssmirkingrevenge » Wed Sep 01, 2010 12:54 am

Gun Freak wrote:Well this is certainly a new concept.


I had actually proposed a similar idea on spudtech as a pneumatic "valveless" concept ;)

The projectile is retained by a chord (high tensile fishing nylon?) and is fired by a hot wire cutting it thus releasing the projectile. A perfectly airtight projectile would have too much drag, so the best idea would be to have an O-ring at the breech so it is only 100% airtight when it needs to be.


It was just a theory though, it's great to see it being actually implemented :) spudamine, what are you doing for fuelling? In spite of some success with smaller chambers on my part, fuelling is far from reliable with the methods I have tried to far.
  • 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: Moonbogg » Wed Sep 01, 2010 10:55 am

lol that was cool. I like the idea. Pretty unique.
  • 0

User avatar
Moonbogg
Major General
Major General
 
Posts: 1375
Joined: Mon Oct 13, 2008 10:20 pm
Location: whittier, CA USA
Reputation: 0

Unread postAuthor: spudamine » Wed Sep 01, 2010 2:00 pm

I had actually proposed a similar idea on spudtech as a pneumatic "valveless" concept


I thought somebody would've probably come up witth something along these lines before, why am I not surprised it was you :lol:
I was also thinking of fishing line, it even comes with different breaking strain ratings. I'm a bit worried about the friction of the o-ring in the barrel but it seems to work for those sureshot compound rounds, hopefully the added friction will just cancel out the removal of blowby.

Damn I'm out of schraders, I've even nicked one from my spare inner tube, sod's law I get a puncture tomorrow.

EDIT:
as for the metering, first stop will be having a go with the manometric system from my old hybrid. If that fails then I'll need to have a good think about it :?
  • 0

User avatar
spudamine
Sergeant Major
Sergeant Major
 
Posts: 184
Joined: Sun Nov 23, 2008 2:47 pm
Reputation: 0

Unread postAuthor: Gun Freak » Wed Sep 01, 2010 5:06 pm

Now that I think of it, it is kind of similar to the valve in this gun.
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Unread postAuthor: jackssmirkingrevenge » Thu Sep 02, 2010 12:27 am

spudamine wrote:I thought somebody would've probably come up witth something along these lines before, why am I not surprised it was you :lol:


Well you thought of it independently and actually built it, so credit to you :)

as for the metering, first stop will be having a go with the manometric system from my old hybrid. If that fails then I'll need to have a good think about it :?


A manometric system might be the way to go, I have a couple of spare gauges and regs. Either that or decanting from a larger premixed chamber.
  • 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

Sponsored

Sponsor
 


Unread postAuthor: jackssmirkingrevenge » Wed Dec 22, 2010 12:42 am

Go figure, the idea was patented as far back as 1890 :roll:
  • 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: spudamine » Wed Dec 22, 2010 4:17 pm

the object of my invention is to prevent the projectile from being puffed partly or entirely out of the gun before the propelling force is sufficiently developed
:lol:

I guess faster burning propellants finished this one off.

I've shelved this idea for now, far too fiddly for mass production of cartridges and it's too bloody cold to make anything at the moment anyway.
  • 0

User avatar
spudamine
Sergeant Major
Sergeant Major
 
Posts: 184
Joined: Sun Nov 23, 2008 2:47 pm
Reputation: 0

Unread postAuthor: Hotwired » Wed Dec 22, 2010 6:21 pm

I can see it being an interesting way for high power automatic fire however.
  • 0

User avatar
Hotwired
Lieutenant General
Lieutenant General
 
Posts: 2599
Joined: Fri Oct 13, 2006 5:51 am
Location: UK
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Thu Dec 23, 2010 8:34 am

spudamine wrote:I guess faster burning propellants finished this one off.


Not really, thePAW 600 uses a similar system where the projectile is released when a retaining rod fails when a certain pressure is reached, and in some ways the basic design of most western 40mm grenade cartridges relies on the same principle.
  • 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

Return to Hybrid Cannon Discussion

Who is online

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

Reputation System ©'