Spring powered cannon

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
mrwonderful239
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Mon Oct 13, 2008 9:51 pm

I've been debating whether to try this option but decided to post it on here first in case I've overlooked something. would u think it would be a good idea to have a cannon (launches nerf rockets) that worked like a oversized airsoft gun. a large spring coiled up that i unleashed that would compress and concentrate the air into a nozzle shooting the projectile. good idea?
TurboSuper
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Mon Oct 13, 2008 10:02 pm

Well, the thing with large springs is that they need more power to draw them back.

If you don't mind a little arm exercise...why not?
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Lentamentalisk
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Mon Oct 13, 2008 10:05 pm

by which you mean your standard Nerf gun? They are already made. Look at the Nerf Crossbow, or any other of their millions of models.
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mrwonderful239
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Mon Oct 13, 2008 10:13 pm

no not a standard nerf gun. those are weak. i mean a nerf rocket like this. for a projectile.

http://cgi.ebay.com/Nerf-Pocket-Vortex- ... dZViewItem

and use an over sized airsoft gun to launch it as if it were a BB.
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Lentamentalisk
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Mon Oct 13, 2008 10:16 pm

there is no way you will be able to pull a spring big enough to launch that with any more power than you could throw it, with out either a pulley system (I was working on one of those for a while) or a crank, like a crossbow. I would go for compressed air any day.
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mrwonderful239
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Mon Oct 13, 2008 10:26 pm

and what if i could come up with a way to fine a way to pull back a spring like that? and where could i find a spring like that... i mean it would have to be like 3 inch in diameter or at least 2. the widest one i've seen was like a inch.
SEAKING9006
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Mon Oct 13, 2008 10:38 pm

Well, you could find one on McMaster, but its really not the way to go. An HPA or Co2 tank on a portable pneumatic is a far better way to fire those puppies. The Brits tried that crap 60-70 years ago in the PIAT anti tank launcher.


Needless to say, it was a dismal failure of a combat weapon.
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Hotwired
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Mon Oct 13, 2008 10:45 pm

Motor vehicle suspension?

I'm not seeing many worthwhile advantages by having a sprung air ram to generate the air blast instead of having an air chamber and releasing that with a valve.

Seaking: The PIAT didn't launch projectiles using a spring, that was only there for driving the massive firing pin into the propelling charge in the rounds. It wasn't as powerful as the rocket type weapons but it had its uses.
Last edited by Hotwired on Mon Oct 13, 2008 10:57 pm, edited 1 time in total.
mrwonderful239
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Mon Oct 13, 2008 10:49 pm

well I've looked into using co2. but i'm trying to learn how it would work like this



but i have no idea what parts you would need or how to make it very safe. besides the obvious sprinkler valve and co2 tank...
explsvcookie257
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Mon Oct 13, 2008 10:55 pm

You have some learning to do my friend

First off you got know how to glue the pvc correctly

get a regulator for that co2 tank cuz unregultaed co2 will make you cannon blow up

all your parts have to be nsf pw or nsf 61 same goes with pipe it will say nsf pw then a pressure ratting

then your going to want to mod the sprinkler valve and all this info can be found using th search button or just readin like i did and read up alot you dont want to be a noob and blow your gun up in your face cuz pvc doesnt show up in xrays well maybe if you spray painted metalic spray paint.

ok bye hopes this helps imm off to bed. sorry about typos im really tired and its midnight
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i-will
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Tue Oct 14, 2008 2:07 am

if it's just a fun little project go for it. but if ur tryin to turn heads than spring is not the way to go. an airsoft sniper rifle has a 6mm barrel that needs a big strong spring to move the air quick and strong enough. imagine the spring it'll take to push that nerf through a half inch barrel.

combustion and compressed air r the answer.

:D go make a cannon and be sombody :D
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Ragnarok
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Tue Oct 14, 2008 5:41 am

mrwonderful239 wrote:a large spring coiled up that i unleashed that would compress and concentrate the air into a nozzle shooting the projectile. good idea?
No, and I have the scars to prove it. Springers are dangerous if not built professionally, and it's not something to mess around with.
Does that thing kinda look like a big cat to you?
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jackssmirkingrevenge
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Tue Oct 14, 2008 5:55 am

Hotwired wrote:The PIAT didn't launch projectiles using a spring, that was only there for driving the massive firing pin into the propelling charge in the rounds. It wasn't as powerful as the rocket type weapons but it had its uses.
As the man says, the PIAT was a spigot type weapon that fired a projectile with a hollow tail containing a firing charge:

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Instead of a projectile inside a barrel, the hollow tail fitted over the spring loaded spigot that ignited the firing charge and put pressure on the projectile as long as the tail still covered the spigot. While not the best weapon in the world, it was used with reasonable success during the second world war and beyod.

The Blacker Bombard operated on the same principle:

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hectmarr wrote:You have to make many weapons, because this field is long and short life
TurboSuper
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Tue Oct 14, 2008 7:25 am

I'm going to have to disagree with the fact that you could throw it farther than a spring would shoot it.

I have a toy Nerf gun which can shoot a good 30'-50', and is designed for little kids to use. Now imagine if it had a longer sleeve and a draw weight comparable to a hunting bow...I imagine it would have quite a bit of power. At least enough power for an airsoft match.

Anyways, a CO2 setup is the next step up, and would be your second option if you don't mind the added complexity.
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CYANIDEGENOCIDE
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Thu Nov 06, 2008 12:08 pm

Interesting concept, but you would probably be better off using a single leaf spring from a car, cut in half. Then weld each half to a collar which would fit around a steel pipe sort of like a giant crossbow. then you could use a come-a-long to pull a cable stung between the leaves.
By the time you get all that done you would probably just prefer to shoot shovels or some other arrow type projectile.
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