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 74 users online :: 3 registered, 0 hidden and 71 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

mini hybrid win!

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

Unread postAuthor: jackssmirkingrevenge » Mon Nov 22, 2010 2:02 am

I had done some testing here, the fragments were flying fast enough to penetrate beer can.
  • 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: ilovefire » Mon Nov 22, 2010 2:17 am

thats impressive, but not all that surprising, i mean you dont just expect all that lead to just stop dead still :lol:
  • 0

User avatar
ilovefire
Colonel
Colonel
 
Posts: 511
Joined: Sat May 22, 2010 6:48 am
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Sun Nov 28, 2010 4:45 am

Tried a shotgun round using a plastic marker cap as a sabot, guess what happened :roll:

[youtube]http://www.youtube.com/watch?v=k8tpUs2X8jE[/youtube]

As you can see the sabot fragments made it to the target first, followed by the lead shot that was obvious not very energetic, having only the gas blast to push it along...

Here's what's left of the sabot:
  • 0

Attachments
sabotfail.JPG
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: ilovefire » Sun Nov 28, 2010 6:23 am

ha ha ha what about making a cup out of layered aluminium foil, not sure if it would work but i think its worth a try
  • 0

User avatar
ilovefire
Colonel
Colonel
 
Posts: 511
Joined: Sat May 22, 2010 6:48 am
Reputation: 0

Unread postAuthor: Labtecpower » Sun Nov 28, 2010 7:28 am

never had anything like it with my piston cannon....
I would think that a plastic cup should be strong enough to survive the blast :roll:
  • 0

User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: saefroch » Sun Nov 28, 2010 11:39 am

I see a good application for a solid steel sabot...
  • 0

User avatar
saefroch
Major General
Major General
 
Posts: 1679
Joined: Mon Jun 08, 2009 8:47 am
Location: U.S.A.- See Map
Country: United States (us)
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Sun Nov 28, 2010 11:54 am

saefroch wrote:I see a good application for a solid steel sabot...


Actually, a 12 gauge shotgun sabot would be perfect, fits nicely in the barrel and can take the 12-15,000 psi the firearm generates - I just don't have any around at the moment.
  • 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 01, 2010 1:21 pm

The hybrid R&D persists, I made a new chamber for a 0.75" barrel, this time just over three times volume of my previous one at 90mL. Tried it out at 6x and it was louder than the smaller one at 12x, which already exceeds tolerable noise levels for an urban environment, so I decided to make a suppressor to see what extent I can reduce the noise. It's a pretty basic design with 2 expansion chambers, but the suppressor tube is 100mm diameter drain pipe which gives it a total volume of over 5 litres :D currently curing, will probably test it tomorrow.
  • 0

Attachments
75hysd.gif
75hysd.gif (2.98 KiB) Viewed 773 times
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: Fnord » Wed Dec 01, 2010 2:32 pm

100mm diameter drain pipe... 5 liters


?!

How long is the barrel again?

Properly designed, a five liter silencer should be good for anything up to and including a stealth hand-grenade. I know the other one you made didn't do much, but if this doesn't work you must be doing it wrong :P

Did you back the epoxy plugs with anything, to avoid fragmenting them when that pressure wave hits? They look pretty thin in the diagram.

Also, how do you intend to aim a .75" bore with a drainpipe in the way?
  • 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: JDP12 » Wed Dec 01, 2010 2:45 pm

Looks awesome!! Can't wait to see the pictures.

Fnord... you could add a sight along the suppressor, or paint a line along the top of the suppressor to aim down, or if you really wanted to, add a laser sight to the tip of the suppressor.
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Wed Dec 01, 2010 2:57 pm

Fnord wrote:How long is the barrel again?


Around 75cm

Properly designed, a five liter silencer should be good for anything up to and including a stealth hand-grenade. I know the other one you made didn't do much, but if this doesn't work you must be doing it wrong :P


The one I made for the mini wasn't exactly well made in the sense I was concerned about losing power so the porting was fairly limited. A "proper" suppressor would look something like this one ;)

Did you back the epoxy plugs with anything, to avoid fragmenting them when that pressure wave hits? They look pretty thin in the diagram.


Some very rough calculations for say a 5 litre suppressor + barrel and 100mL chamber generating 1000 psi, worst case scenario if you plug the muzzle it's not going to generate more than 20 psi, so I'm not too worried. Besides it's not just epoxy, I threw inthis filler, the result is incredibly tough and the plugs are over 1cm thick. The pipe wall thickness is only 1.5mm so it's not the plugs that are the weakest point anyway.

Also, how do you intend to aim a .75" bore with a drainpipe in the way?


This is more of a test rig so aiming is not really a concern.
  • 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: JDP12 » Wed Dec 01, 2010 3:07 pm

Is there a name for this filler, or perhaps a substitute one could use?
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Wed Dec 01, 2010 3:16 pm

JDP12 wrote:Is there a name for this filler, or perhaps a substitute one could use?


This is the stuff.

There are other improvised options for thickening up epoxy though, in the past I've used sawdust or even talcum powder.
  • 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: Fnord » Wed Dec 01, 2010 3:46 pm

er... fiberglass?
  • 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: jackssmirkingrevenge » Wed Dec 01, 2010 4:20 pm

Fnord wrote:er... fiberglass?


...as a wrap, but not as a filler, right?
  • 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

PreviousNext

Return to Hybrid Cannon Discussion

Who is online

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

Reputation System ©'