Help with a constant air 2" nerf rocket cannon

brad0896 · Thu Aug 08, 2013 12:18 pm

Hi guys! I have built a couple of pneumatic cannons over the past few years but now I want to step it up a notch. I play milsim airsoft and the game I am going to be playing at I need to make a 2" nerf cannon to be able to take out vehicles. This needs to be something that I can attach a paintball hpa or co2 tank to. I want to go with the single line look similar to a LAW. I understand how to make simple cannons. I was wondering if you guys could help me with the design of a constant air nerf launcher. I attached a pic of something i would want it to look like, i just need to know how to make it a constant air cannon. thanks!

Gun Freak · Thu Aug 08, 2013 12:42 pm

What exactly do you mean by constant air cannon?

brad0896 · Thu Aug 08, 2013 2:50 pm

I guess that didn't make much sense lol. I want a constant supply of air going to the air chamber so once I fire ( by moving the ball valve lever down) I can return the ball valve lever to the closed position. Then the air can just fill up the air chamber again. What I need to know is how to limit the amount of air that goes into the air chamber to about 150 psi. Is that even possible? Or should I look into another design. Sorry I really don't know what I am doing on the project but it needs to get done somehow

Gun Freak · Thu Aug 08, 2013 3:21 pm

Ah ok. Gotcha.

I'd start with an HPA tank rather than CO2 because you don't want to freeze your gun. Or you could make it out of metal... But I was going to suggest a pvc chamber filled by a regulated HPA tank. You just have to buy a regulator. I believe Palmer makes some good regulators that will dial it down to the pressure you need. They're called low pressure regulators or stabilizers I believe, just look them up. From there I would use a modded sprinkler valve to keep things simple; that way it would close right away so your chamber can fill up and it is actuated by an actual trigger unlike a ball valve. Then a few feet of 2" PVC nerf vortex barrel and you're all set!

brad0896 · Thu Aug 08, 2013 3:46 pm

Thank you so much for your help! I really appreciate it!

dart guy · Thu Aug 08, 2013 3:58 pm

I have an idea in the rough for you but it isnt finished. I am thinking of a little bit of a complicated to make launcher that would employ a burst disk loaded cartrige that if you use it it will need a new "shell" to be breech loaded and a way to charge your inner air tank to a higher pressure to realy launch that sucker fast. Between 100fps-400fps, just a guess, send me a pm and i will give you the rough idea when i am done.
Though i am no jsr or "gun freak" i do have some great ideas i was actualy thinking about a hybrid smaw so i had some spin off ideas.

tigerblues28 · Thu Aug 08, 2013 4:22 pm

dart guy wrote:I have an idea in the rough for you but it isnt finished. I am thinking of a little bit of a complicated to make launcher that would employ a burst disk loaded cartrige that if you use it it will need a new "shell" to be breech loaded and a way to charge your inner air tank to a higher pressure to realy launch that sucker fast. Between 100fps-400fps, just a guess, send me a pm and i will give you the rough idea when i am done.
Though i am no jsr or "gun freak" i do have some great ideas i was actualy thinking about a hybrid smaw so i had some spin off ideas.

Dart: I don't think a cartridge burst disk would be the best idea. seems expensive and a little slow to use in war.
I agree with gun freak and go with a modded Sprinkler valve with a breach.
Nick