Pneumatic mortar idea

[sharpshooter11000]

Here's my idea for a pneumatic mortar. I haven't been bothered to make it yet.
The picture is of the shell, it would be dropped into a tube with pretty much the ID of the OD of the shell. The tube would be sealed with a plug at the end and have a firing pin coming through the plug, like a real mortar. The firing pin (should) burst the burst disk and fire the shell.
On the picture:
Green- Foam nosecone
Grey- Plastic body
Blue- Schrader
Red- burst disk

[jackssmirkingrevenge]

Burst disk attachment? That's the annoying bit...

[sharpshooter11000]

Yeah but its the only way I could think of that you could have multiple shells being fired rapidly. You could make lots of shells on a lathe and have them all pre-charged. The thing that I'm not sure about is would a pin burst a burst disk with the shell being that light (it would only be made out of nylon or something)?

[warhead052]

The pin would be easy to make. Just get a nice long nail, and sharpen the tip even more. Then fill the shell with enough pressure, and the nail should pop it on contact.

[sharpshooter11000]

I was thinking something like that, but I wasn't sure if it would pop the disk. What could i use as a burst disk?

[warhead052]

Depends, what sort of pressure do you want? And what is this going to be used for? I would say use aluminum foil.

[sharpshooter11000]

I don't know what pressure to use, I'm limited to 100psi with my compressor, i was thinking somewhere around that? It would just be used for fun or maybe if I could make a safe enough round for airsoft.

[Petitlu]

handling a projectile already under pressure is dangerous ...

[jackssmirkingrevenge]

Yeah but its the only way I could think of that you could have multiple shells being fired rapidly. You could make lots of shells on a lathe and have them all pre-charged. The thing that I'm not sure about is would a pin burst a burst disk with the shell being that light (it would only be made out of nylon or something)?

Use some imagination, here's an alternative. Projectile strikes a pin which exhausts the pilot volume, opening the piston and firing the projectile, after which the valve reseals and it's ready for the next shot

[warhead052]

Ok. Well I would suggest aluminum foil then.

[sharpshooter11000]

handling a projectile already under pressure is dangerous

Not much more dangerous than a cannon/cartridge under pressure I would think. The projectiles would be properly made on a lathe, and if I end up making it they will have safety caps over the burst disks to prevent accidental firing.

JSR, i thought of something like that but I wanted it to be a simple tube and more complicated shell.

Warhead, Thanks, if I make it I'll use aluminium foil

[Petitlu]

projectiles would be expensive to do!

Jacks solution is better, cheaper and safer

[sharpshooter11000]

projectiles would be expensive to do!

projectiles is cheap!
€ 4 to 20! and are easy to do because no O-ring

I can get scrap material for free from a professional machinist and machine them myself.

[Petitlu]

heu :

"projectiles is cheap!
€ 4 to 20! and are easy to do because no O-ring"

quotation another post

[jackssmirkingrevenge]

JSR, i thought of something like that but I wanted it to be a simple tube and more complicated shell

You can always reverse it, have the valve on the shell.

You could probably use a soda bottle and hold a burst disk in the cap for a cheap and cheerful projectile...

projectiles would be expensive to do!

Jacks solution is better, cheaper and safer

Definitely ironic considering the other thread