SpudFiles

Hey im new to the forums and have only made one cannon(over under sprinkler valve. i will post it but its not anything special) Now i want to make another one. I am going to make it a piston but was wondering if i should do another over/under or if i should go coaxial. Its going to have a 4 inch diameter chamber and 2 inch barrel. also how hard would it be to pump this with a bicycle pump. thnx for the info.

Woah..if its gonna be that big of a bore i suggest a combustion

my dad wont let me. only pnuematic. so i decided why not go big. oh and if someone could post a link on how to make a good piston it would be helpful or i will just do some more searchin myself

Why will he not let you make a combustion cannon.

With dimensions that size I recommend a coaxial

Why can't you build a combustion launcher? For a first build, you'll be far safer with one of those than a pneumatic (no constant pressure, generally less pressure produced), and you won't have to worry about an expensive 2" valve.

If you're really intent on pneumatic, as frankrede stated, a coaxial pneumatic piston valve is probably the way to go?

thnx guys. yah thats what i figured but wanted to make sure. the hardest part is going to be getting the money and making the piston

the hardest part is going to be getting the money and making the piston

Actually, if you're creative enough, you could probably do this for under $100, if the parts are available locally. What material do you plan on using?

This is for a 2" piston but it gives you the general idea of how to make one:
http://www.instructables.com/id/Golfbal ... -Build-one -That-Shoo/

I suggest a coaxial even if I was also planning on building a 4" chamber overunder.