Big pneumatic GB cannon

[SpudFarm]

well, now that the snow starts to melt and my last hobby is to noisy i am slowly getting back into spudgunning mixed with computer modding/designing.

so you remember when i was making UPGBH10x (also known as the hybrid that larda made the chamber, barrel and some other acesories on) i got a pressure test done in a test chamber, this chamber is to cool to rust away..

so the plan is to make a pneumatic golf ball cannon, it will use the test chamber for air reservoir, a piston valve and a 3m long hydraulic pipe with a I.D of 42mm as barrel.

it is a while since i thought about spud guns so i need someone to look over and come with constructive comments.

some specs:
chamber: 5" steel with 7mm walls, unknown length but around 60cm.
barrel: read above
valve: piston valve.
operating pressure: atleast 150psi.

the end plates is 1cm thick and that is where i first hit problems, i don't know if 1cm of 2" threads is safe at 150psi. but if i absolutely have to i can weld a pipe in the end plate and thread the pipes inside (mabe outside, depends on how i feel)

it will have to have good enough reload times to not get me bored and make me quit spudding again. so there i need some help to if anyone has a cheap tip.

also, what would you think about using a barrel that long when using the chamber i am going to use? mabe not optimal for light ammo as golf balls but what about lead slugs.

oh, and how would you place a piston in a 2" galvanized tee?

finally, what do you think performance wise?

[jonnyboy]

the end plates is 1cm thick and that is where i first hit problems, i don't know if 1cm of 2" threads is safe at 150psi. but if i absolutely have to i can weld a pipe in the end plate and thread the pipes inside (mabe outside, depends on how i feel)

Those clean out caps blow out on combustion's and those go about 1cm in as well. I would make the threads as deep as you can make them within reason. There's really no downside to making them a little deep.

oh, and how would you place a piston in a 2" galvanized tee?

Well you put the piston in one of the linear ports.

I assume you mean extending the pipe into the tee.
I forget who but somebody made a how to on how to do that with metal parts. It should be in the how to section.

it will have to have good enough reload times to not get me bored and make me quit spudding again. so there i need some help to if anyone has a cheap tip.

Camlocks would work but I'm not sure if they have them in a size suitable for your barrel.

A bolt action golf ball gun would be cool.
8)

BTW your barrel extends way to far into the tee on your design it should only go halfway in.

[SpudFarm]

the end plates is 1cm thick and that is where i first hit problems, i don't know if 1cm of 2" threads is safe at 150psi. but if i absolutely have to i can weld a pipe in the end plate and thread the pipes inside (mabe outside, depends on how i feel)

Those clean out caps blow out on combustion's and those go about 1cm in as well. I would make the threads as deep as you can make them within reason. There's really no downside to making them a little deep.

oh, and how would you place a piston in a 2" galvanized tee?

Well you put the piston in one of the linear ports.

I assume you mean extending the pipe into the tee.
I forget who but somebody made a how to on how to do that with metal parts. It should be in the how to section.

it will have to have good enough reload times to not get me bored and make me quit spudding again. so there i need some help to if anyone has a cheap tip.

Camlocks would work but I'm not sure if they have them in a size suitable for your barrel.

A bolt action golf ball gun would be cool.
8)

BTW your barrel extends way to far into the tee on your design it should only go halfway in.

caps is made out of steel plate and the chamber is tested to 2800 psi so i dont think the cap itself is a problem

the thing about the tee is the rough inside of the tee. and i have no space to lose with a copper pipe sleeved in since i have a gross surface area from the start of.
the surface area is also the reason i have the barrel that long back.

cheers

[psycix]

chamber: 5" steel with 7mm walls, unknown length but around 60cm.

Holy crap.
That deserves some better use then a 150psi GB cannon.

I'll vote for a 500+ psi pneumatic, possibly burst disk. Or just do the hybrid thing, the chamber just screams for it.

it will have to have good enough reload times to not get me bored and make me quit spudding again. so there i need some help to if anyone has a cheap tip.

Figure out something (semi) automatic. Maybe that wont get you bored so fast.

[SpudFarm]

i already have a bigger chamber like that used for a hybrid

500psi will get me bored since i need to lug around with a nitrogen cylinder. burst disk is NOT an option, slow realoding as he** and as you know, i have problems finding a good union in Norway.

mabe i should concentrate on the UPGBH10x and making that better, og make another hybrid out of the test chamber that is handheld but that is certainly not something to get me going again, i need something that is quick and simple to get the interest up again.

however, if the other thread about Burst disk holders get a really good post with an even better diagram or idea i will try it on my hybrid.
if that works i will just make one more hybrid that i can hold while i fire.

imagine the sensation of force you get if you fire a 100g lead slug supersonic from your hands, but the pain in the but after falling would be even worse!