SpudFiles

I had an idea on how to make a cannon that operates off a 12 gram Co2 that operates like a burst disk cannon.

The far majority of the launcher would be made from PVC, off the end would be a 12 gram changer that could be unscrewed (for changing the bursting device). Could a 12 gram, once punctured, inflate and rupture an attached section of latex tubing. If the pressure is not enough or the tubing is too large, a sharp point inside the barrel to pop the latex tubing and fire the cannon.

Would this work for a cannon?

i don't know if a latex tube would work or not, i have used a 4" latex tube in a landmine as a burst tube, it would expand almost a foot before it would burst, but there is a launcher like you described that uses tinfoil as a burst disk.

We sometimes use this for practical jokes at work A length of rubber tube sealed and tied to the compressed air line with cable ties. A line from a ball valve to the door handle opens the air and *BOOM*

grumpy wrote:i don't know if a latex tube would work or not, i have used a 4" latex tube in a landmine as a burst tube, it would expand almost a foot before it would burst, but there is a launcher like you described that uses tinfoil as a burst disk.

It could be a short length of tubing so it does not get too big. Latex tubing is comonly availible at paintball games and would be easier to use I think.

We sometimes use this for practical jokes at work Smile A length of rubber tube sealed and tied to the compressed air line with cable ties. A line from a ball valve to the door handle opens the air and *BOOM* Very Happy

Using the BOOM to propel a small projectile. To me that boom is alot of energy, sticking it in a barrel and a projectile between it and its exit. In theory, it should at shoot something with a bit of power.


The nice part about it I think is that the air/co2 is already in the barrel and behind the projectile. It would grow rather big, pop or be popped, the latex tubing splits and rapidly snaps back to its small size, and the projetile is fired.

Orpackrat wrote:Using the BOOM to propel a small projectile. To me that boom is alot of energy, sticking it in a barrel and a projectile between it and its exit. In theory, it should at shoot something with a bit of power.

Why not just use a burst disk though?

Why not just use a burst disk though?

To make a light weight cannon that consists of burst tube, barrel, 12 gram changer. It would be very easy to reload and change out the burst tube in a paintball game.

Unscrew
pull off old tube
Slide on new
screw back on
new 12 gram and projectile

Also latex tubing is readily availible and being compact is a must.

Haveing the air chamber (latex tubing) and valve/burst tube inside the barrel seems like it would be more compact. The goal size of the laucher is to be about the size of a 140 round pod.

Correct me if I'm wrong but a normal burst disk, when the disk ruptures, the air must travel through the rupured area, build behind the projectile, and then push the projectile out.

The idea with this cannon is to have a bust disk like cannon but the burst disk is the air chamber. Once ruptured, it has already filled the space behind the projectile and instead of rushing into a small chamber behind the projetile and then firing the projectile, it fires the projectile without having to move to another area. In theory, that area that the latex tube expands in, the bigger the expansion, the larger your valve is so to speak.

In a burst disk, it's like having a ball valve the same diameter as your barrel that opens at maximum flow in a tiny fraction of a second. Effectively your idea operates on the same principle, only instead of closing off the barrel, you've turned the entire "chamber" into a burst disk.

It would work as far as I can tell, and it's also to some extent a safe way to use unregulated CO2.

you mean like this?

The latex tubing fills tha back half of the barrel, either too much pressure burst the tubing or a point inside. The projectile sits as far back as possible. When the latex tubing expands, I pushes the projectile a little up the barrel before firing, this should allow little dead space.

The cannon would be 2 main parts. The barrel assembly and the 12 gram changer and burst tube. To replace the burst tube, unscrew from the barrel assembly, take the old one off and slide the other on (with locking ring). Screw back together. A perfect air seal where the 12 gram connects to the barrel is not need since the pressure will take the easiest route, shooting the projectile.