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My first pnuematic launcher/Artillery piece.

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
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My first pnuematic launcher/Artillery piece.

Unread postAuthor: B to the RAD » Tue Apr 22, 2008 10:54 pm

I am really big into airsoft with Battlesim (battlesim.com) and I would like to add a little more realism to some of our games, Using some "actual" artillery. I am planing on firing full size Nerf footballs, probably weighted in the center for flight stability. I would like to be able to shoot a 1/4 mile. Lastly it should look somewhat like a real artillery piece.

I have experience building Items like this I have built a non firing PAK 40. I would like suggestions for tank and barrel diameters, barrel length I am planing on at least 8'. I am wondering if the 12 volt compressor I just got would be suitable for getting at least 1 shot of per minute?

Thank you for any help.
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Unread postAuthor: FordGtMan » Tue Apr 22, 2008 10:57 pm

Many people have at4 replicas that you can base your design on. I am not sure if you can get that 1/4 mile too easily though. I think you would need to have something more pressure suited to get those distances.
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Unread postAuthor: MrCrowley » Tue Apr 22, 2008 11:03 pm

12v compressor wont be enough. You'll need some big chambers, it will burn out after a few shots.

A 1/4 mile is a very long distance, especially with a nerf, though the added weight will help. I'd say a 10' barrel would be minimum, and maybe four 4" chambers, each 36" long. You'll need a piston valve as well with such a short barrel and small chamber, a 4" piston would probably be the best.

I'm not even sure if that would make a 1/4 mile. I have no experience with nerfs as projectiles. You can try and model a gun on <A HREF="http://www.thehalls-in-bfe.com/GGDT/main_menu.html">GGDT</a>. It allows you to enter specs of your cannon and it then calculates various things like muzzle velocity, energy, distance etc.
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Re: My first pnuematic launcher/Artillery piece.

Unread postAuthor: Blitz » Wed Apr 23, 2008 12:55 am

B to the RAD wrote:I am really big into airsoft with Battlesim (battlesim.com) and I would like to add a little more realism to some of our games, Using some "actual" artillery. I am planing on firing full size Nerf footballs, probably weighted in the center for flight stability. I would like to be able to shoot a 1/4 mile. Lastly it should look somewhat like a real artillery piece.

I have experience building Items like this I have built a non firing PAK 40. I would like suggestions for tank and barrel diameters, barrel length I am planing on at least 8'. I am wondering if the 12 volt compressor I just got would be suitable for getting at least 1 shot of per minute?

Thank you for any help.


I'm afraid those 12v compressors will overheat and burn out before you get any decent pressure in your cannon. Weighed nerf footballs, those are allowed? I'd hate to be pelted with one regardless of what the distance is...

Barrel diameters... Well, I went with 4" on my cannon but you may want to go with 3" -- that's an awesome diameter for quite a few projectiles. The only reason I chose 4" is because I have access to a lot of coffee cans and apple sauce jars that fit perfectly. :twisted:

I am going to presume you will be breech-loading this thing. In a tank, you'll want access to the breech directly behind it, so using a tee with the rear coaxial to the barrel is your best bet. Your valve can go between the bottom of the tee and the chamber. Whatever diameter you use for the barrel, use for the chamber. You can make a tight over-under design so it doesn't look too ridiculous when mounted in your tank.

Although my suggestions are for tank turrets, they can also be applied to "towed" artillery. With that, you can have more air chambers lined up parallel to your barrel. You'll have a bit more luxury in terms of space.
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Unread postAuthor: biggsauce » Wed Apr 23, 2008 1:02 am

Hoowee, 1/4 mile! Its been said above, in better words than I have.

How tight of a budget do you have? I guess if you had enough 12v compressors goin, it may not be too bad, but a half dozen compressor means batteries, and a few $$$.

A generator/compressor? A HPA/SCUBA tank? Of the two, I would go with the HPA/SCUBA tanks option. But as with anything, all it takes is a checkbook and a dream to make anything happen...
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Unread postAuthor: Blitz » Wed Apr 23, 2008 1:05 am

biggsauce wrote:A generator/compressor? A HPA/SCUBA tank? Of the two, I would go with the HPA/SCUBA tanks option. But as with anything, all it takes is a checkbook and a dream to make anything happen...


For a artillery piece that size, that he'd want to fire more than a few times, this really is the only reasonable option. Otherwise, that's a LOT of power and mobility lost, and it just becomes logistically crappy.
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Re: My first pnuematic launcher/Artillery piece.

Unread postAuthor: jimmy101 » Wed Apr 23, 2008 1:05 pm

B to the RAD wrote: I am planing on firing full size Nerf footballs, probably weighted in the center for flight stability. I would like to be able to shoot a 1/4 mile.

Not possible.

You would have to add a fair amount of weight to get a nerf football to fly 1/4" mile. At that mass, and muzzle velocity, it would be much to dangerous to fire at a person.

BTW, adding weight to the center of a nerf football will do nothing in terms of stabilizing it in flight. You need to add weight to the nose. Or, remove mass, but not surface area, from the tail.
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Re: My first pnuematic launcher/Artillery piece.

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Unread postAuthor: jrrdw » Wed Apr 23, 2008 5:30 pm

MrCrowley wrote:12v compressor wont be enough. You'll need some big chambers, it will burn out after a few shots.

A 1/4 mile is a very long distance, especially with a nerf, though the added weight will help. I'd say a 10' barrel would be minimum, and maybe four 4" chambers, each 36" long. You'll need a piston valve as well with such a short barrel and small chamber, a 4" piston would probably be the best.

I'm not even sure if that would make a 1/4 mile. I have no experience with nerfs as projectiles. You can try and model a gun on <A HREF="http://www.thehalls-in-bfe.com/GGDT/main_menu.html">GGDT</a>. It allows you to enter specs of your cannon and it then calculates various things like muzzle velocity, energy, distance etc.


Acording to Cecile County Drag Way a 1/4 mile is 1420 feet.

I agree with the above, those little 12v compressors wont give you what your looking for.

Maby a large C02 bottle fully charged and regulated would probly give you some of what your looking for.

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Unread postAuthor: MrCrowley » Wed Apr 23, 2008 5:37 pm

Yeah it's about 400m, which I can reach with my SGA at 120psi and a golfball, but this is a nerf...

@Brad,

Why do you need it to shoot 1/4 mile?
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Unread postAuthor: LikimysCrotchus5 » Wed Apr 23, 2008 5:38 pm

Since a mile is 5280 feet, you divide that by 4.

5280/4 = 1320 feet. Thats a quarter of a mile. Guess you must have misread.
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Unread postAuthor: pat123 » Wed Apr 23, 2008 5:41 pm

Why do you need it to shoot 1/4 mile?

yeah there is no way you will be able to hit withen 20-50ft of the person at that distance.
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Unread postAuthor: B to the RAD » Wed Apr 23, 2008 10:36 pm

Actually this would most likely be shot at me and other OPFOR players. (not open to the public) for training purposes at a 5 day vietnam living history event.

1/4 mile because the area this will be used in has a open field of about 40 acres and its only about a 1/4 mile wide, the U.S. base will be on one side of this field which is where the piece will be placed.

money isnt really an obstacle but genorator and full size compressor are not really an option.
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Unread postAuthor: elitesniper » Wed Apr 23, 2008 10:39 pm

Hold on, so you want to shoot at 1/4 a mile and accurate enough to hit? That would be extremely hard to achieve due to wind and other things.
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Unread postAuthor: biged » Thu Apr 24, 2008 5:18 am

Diminishing range and lightweight projectiles just won't travel far even if you build a bigger gun.

I tried like hell to get a tennis ball to go a quarter mile, farthest shot was around 600 feet (was also windy). Took 4 minutes to air up the chamber to 150 psi (10.3 bar) with a gasoline powered compressor. Cannon also had a 10 foot barrel on it. (The one in the pic is a 5' test barrel.)
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Tried a nerf rocket with a 10 foot, 2 inch diameter barrel at 150 psi. The nerf came out in pieces. It looked like it was turned inside out. Not one nerf survived, I killed six that day... :?

I am still searching for a safe lightweight projectile than can be launched a long way. (Experimenting with pool noodles.)

///ed///
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Unread postAuthor: judgment_arms » Wed Apr 30, 2008 11:37 am

The key here is: fin stabilized, air burst, canisters loaded with paintballs.
I’m currently working on a design for a similar critter to what you’re looking for, only mine shall shoot 20lb canisters loaded with 3,200 paintballs, should be able to cover an acre at 7/16 of a mile. 8)
The thing will have a 40 foot 4” barrel, four 10 foot 3” chambers, and four 3 inch porting piston valves.
Of course this is all theoretical. ;)

As for AT rounds, your going to need a large canister to get enough NERFs to go ¼ of a mile, for my design to do it it’ll have to be about 18 NERFs…

It just occurred to me that I completely forgot to include the weight of the canister when putting numbers into the GGDT. :oops:
I guess I know what I’m doing next…

EDIT: six days old doesn’t count as dead, does it?

EDIT #2:
Ran more number through the GGDT, decided that NERFS wouldn’t be practical for a long range gun howitzer, being as large and light as they are, even in a canister. You wouldn’t get very good accuracy or a dense enough saturation to be worth wile.
Although, given a big enough cannon, one could put them ¼ mile or better down range using a canister.
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Last edited by judgment_arms on Wed Apr 30, 2008 11:58 am, edited 1 time in total.
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