NASH Air Gun / Cannon

I've had a small fire extinguisher sitting around for a while and since I have more I decided to turn it into an air cannon. The acronym stands for "Nerf Air Soft Homemade" since it can shoot Nerf darts, airsoft BBs, paper rockets (with plastic bottle fins!), and whatever else fits in that wonderful 1/2" barrel. 

Those of you who are older and have more sense in you can shoot AA batteries, but be aware: these can be lethal if they hit a person in certain places. NEVER EVER shoot at a person, animal, or something you don't want to damage!

That said, let's get started. Here's the shopping list (or parts list if you're like me and have a 30' trailer of pure plumbing parts ;-)



(1) Pressure Gauge: Make sure it measures from 0-100 PSI (or near there), has an air fill valve, and 3/4" threads on the bottom.
(1) 1/2" x 3/4" Brass / Iron Adapter (threaded of course)
(3) 1/2" Brass / Iron Nipples (about 2" - 4" long, doesn't matter)
(1) 1/2" Brass / Iron Tee
(1) 1/2" PVC Male Adapter
(1) 1/2" Ball Valve (metal, threaded ends)
(1) Small Fire Extinguisher


That's it! On to the build...

Step 1 Disassemble the Extinguisher

Go outside, pull that pin, and enjoy emptying the extinguisher. Or have a weenie roast and then put out the fire with it. Either way, make sure it is completely empty.

Now depending on your extinguisher, you'll have to figure out how to unscrew the top from the tank. Mine had a metal label with a tab that I secured in a vise and then I used a wrench to loosen it. Turns out the one I have wasn't that tight. Not sure if they are all that way, but take courage! It will come off!

You can use a crescent wrench or channel locks on this guy.

Comments

[Ghostsniper1979]

it does but i fail to see the Nipple for filling, can you explain where it is
thats a funking sweet design by the way,

cheers

[godoggie]

Thanks AJ! Yep that is correct. You might have to do some looking around for a pressure gauge that has the fill valve integrated. Otherwise you can go to ACE hardware and get a fill valve for $0.99 and an adapter fitting that goes from the valve to your pipe size.

[AJMansfield]

In this design it is at the base of the pressure gauge; its that little metal but that sticks out to the side. You may have gotten a pressure gauge that didn't have one, but that isn't that incredibly hard to fix: you can either get a new gauge altogether or just get a new fill valve to attach at another spot (you will need another 'T' piece too, and perhaps some more pipe for this).

[sjoobbani]

I recentely made a fire extinguisher air cannon, but then I realized there might be instructables about it! so I checked, and I noticed that none of them use the existing fire exinguisher valve?!
WHY NOT?!?!?!!
My entinguisher's rated to 595PSI, so basically, I pressurize it
and unscrew the 'stock' nozzle, and screw on a barrel that has a T on it for "auto feed" so It's kind of full auto..

[sjoobbani]

Sorry it took me such a long time to reply!!! I"ve changed up my design!
I didn't really like the 'auto feed' thing I had going on with the T, so I have a 'deep socket coupling' attached.

[godoggie]

Hey looks nice, I like it. I hadn't thought about using a 1/2" m.a. as an adapter... Thanks for the pics!

[sjoobbani]

The trick is, taking your extinguisher into a hardware store, and trying to see which fittings fit the best. I added some JB WELD to it later on to make sure it's solid (like you can see on my pressurizing adaptor) but when I took the picture, it was just pushed down in there!

[godoggie]

Adapting the nozzle to 1/2" PVC pipe can be a pain if you want to do it nicely. Sure you can ghetto something on, but that's not my style. If you unscrew the nozzle, most of them have 3/8" or so MECHANICAL threads, not PIPE threads, so you can't adapt it to 1/2" anything.

I'd like to see a picture of it just for kicks, it sounds pretty cool :)

-GoDoggie

[Ghostsniper1979]

how are you pressurising the tank?

[godoggie]

With a bicycle pump, but you can use an air compressor too. Does that answer your question?

[stevenh429]

and where would i get the pressure gauge like that?

[godoggie]

ACE Hardware, Lowes, Home Depot, most anywhere... Just make sure it goes from 0-100 PSI or so. I'm assuming you live in the US, but if not a plumbing supply or hardware store should get what you need...

--GoDoggie

[stevenh429]

Yes, i live in the u.s. , I go to home depot...
but where would I get the pressure gauge with the valve like that?

[godoggie]

Well I got mine from a plumbing supply company, but if you don't have one around (probably not as they can be few and far between), you might look at trying eBay... I'm not a huge eBay guy, but they might be your best bet as I've been looking online and haven't been able to find many gauges with fill valves. I'll check at my local ACE and see if they carry it (their online store is garbage). I'll keep my eyes out and let you know.

I'm really spoiled because I have a 10' x 30' trailer full of plumbing parts ;-)

--GoDoggie

[stevenh429]

This is THE best instructable ever.
PS, what brand is that fire extinguisher and what kind?

[godoggie]

I don't have the tag but I'm assuming it's a "General" brand, of the Quick-Aid variety. Not that that makes any sense, but any general purpose should do. ABC or anything tested to 300 PSI should work just fine :-)

And thanks, glad you like it!

--GoDoggie

[sithlil]

how far do u think it shoots?

[godoggie]

Well I shot a AA battery about 100 yards @ 100PSI, with other types of ammo it varies. If you use it as a Nerf shotgun, you won't want to pressurize that high.

[didgitalpunk]

true it would just be stupid to have written on your friend's death testament "killed by a nerf dart" XD

[godoggie]

Haha yeah. And have a Felony as a result of "a nerf dart murder"... lol

[hifatpeople]

awesome

[godoggie]

Thanks I'm glad you find it cool too! It's always nice to know that people do indeed read my ible's :-)