SpudFiles

I don't know if this has been done before, but I got the idea from Gort's amazing QCTBDC http://www.spudfiles.com/forums/viewtop ... 300&#57300 and one day I was thinking about how a lot of military mortars are triggered when the shell hits the bottom and then I realized, if a sharp tip was on back of a decently heavy projectile like a battery it could set off a burst disk pneumatic

the great think about this is the ability to set off a burst disk when you want, and this can be done to any current burst disk gun with no mods to the gun its self

I’ve done some testing with a ghetto Gatorade bottle burst disk mini, foil/plastic baggie, and AA batteries wrapped with some duct tape (since I only had 3/4" cpvc and no long 1/2pvc for barrels), and as for puncturing points I found some better effects with pencil point rather than nails, also my barrel fell off so I had to hold it on.
So because my tests were so ghetto, I'm wondering if and one with a burst disk gun fiddle around with the idea

ps. Also leave comments about your opinion or tell me if this is an old idea

im pretty sure i remember reading somebody building one of these search it ...sorry for being so vague

Using a 3/4" barrel you could use empty 12 gram cylinders as ammo. Glue a nail into the pireced hole.

You could also use full 12 gram cylinders and have them landing on a nail to pierce their burst disks

Hotwired wrote:You could also use full 12 gram cylinders and have them landing on a nail to pierce their burst disks

Tried it once, the weight of the cartridge is not enough force to pierce the seal.

Burst disk mortars have been done before - quite successfully.
They're cheap and easy to build, and can be quite a bit of fun. The problem is, if you use weak or non-uniform burst disk material, they can go off randomly, so never leave a projectile in the barrel when it's pressurized. A pressure gauge is a good idea - and a 125-psi pop-off safety is a good idea, also. The pop-off can be used to depressurize the chamber if your projectile didn't pierce the burst disk.
I think 2 liter bottle material and milkjug material make the best burst disks.

Just my input.

Peace,
Pete Zaria.

In tech ed we have been making CO2 cars that run off punctured 8 grams, just hit the back with something in a barrel, should shoot pretty far.

One idea is to do a OU design, with a 12'' 2'' chamber and then a union and then you barrel. And for your ammo make it so that there is a point on the bottom of the ammo.

You could all so do the same thing but use a sprinkler valve when the union would be and then put a metal strips in the bottom, and use them as switch so that when you drop your ammo in you turn the valve on and there you go.

LGM wrote:In tech ed we have been making CO2 cars that run off punctured 8 grams, just hit the back with something in a barrel, should shoot pretty far.

we did that to last year and everybody else shot there's down a race track but with fishing line connected to the bottom of eylets so it wouldnt crash into the walls so in an attempt to by different i built wings on my car and didnt atach it to the fishing line.....it flew......tech teacher"didnt see it" ...............but sorry that was off topic i saw something once while surfing some guy just hit a nai into the end and it went of so what you should do is put the nail on the burst disk then put the co2 canister over the top when the burst disk goes off the nail opens up the co2 canister and so it shoots of while being shot off

yeah I said 3/4" CPVC its a difrent scale than pvc so the barrel I have is mainly for paintballs

o well I geuss its been done before, at least its part of the theory data base, and a few more will know about it

I was thinking about a burst disk mortar recently, but then I had a unique realization about high pressure chambers. A short mortar gun wouldn't utilize volume ratios well, but boosting pressures with burst disks would. I've got an idea on a chamber that would be small but could maybe hold like 1000(or multiples)psi. My question is anyone really intersetd in that?

Foil, in my experience, works most consistently. I've made something similar but not in the vein of a cartridge. The burst disk pneumatic I made last year was posted on the spudtech forums. But I also posted plans on a paintball forum http://www.milsimog.org

The pressures run est 250psi-300psi (100psi below sch40 3/4")

The bottom launcher with the barrel "trimmed" will launch a Nerf over 350fps and may exceed 400fps with a little tweeking