SpudFiles

Hey everyone, this is my first post here and I have a few basic questions.

I'm about to start assembling my first ever pneumatic cannon. It's going to have a 1 1/2" x 62" barrel but I don't know what type of valve to use just yet.
First off, one thing I wondered about was pressure ratings on couplings, are they worth worrying about?

But my main concern is what valve to use. I hope to finish this before this Friday so I don't want it to be too complicated. But at the same time I don't want to skimp out on one of the most important parts. What would you recommend I do?

I would be willing to build a piston valve, but I don't know enough about them, or if it's even worth it considering it's my first time. So far I think I'll just stick with a modified sprinkler valve (unless my dad finds some fancy pants valve at work tomorrow).

So please feel free to flood me with suggestions/tips. I could use as much advise as possible.
Thanks,

A proper piston will be a real challenge to get right by Friday. I suggest you build a modded 1" sprinkler valve gun...Orbit Watermaster at Lowes. Go with either a 36" long 2" dia chamber or a 16" long 3" chamber. Both will give you slightly more that 1:1 c:b volume ratio...a good ratio for this scale of gun. I assume you want to shoot potatos...this will be about as good as it gets. 80-100 psi will be about the max practical without destroying the potato ammo. Other hard ammo is a different story of course.

Here's a quick lesson on modding a sprinkler valve.

[youtube][/youtube]
Use pressure rated connector parts, easy to do if you stay with 2" pipe and less.

There are hundreds of guns here that fit this rough description. Take a good look through the cannon showcase to get more ideas.

Welcome to Spudfiles!

Awesome, thanks alot.

I went to Home Depot earlier and picked up a 24" x 3" piece of pressure rated PVC but when I grabbed the end cap I didn't pay any attention to whether or not it was pressure rated.
(I didn't get any other pieces because I didn't know what I would need to be compatible with whatever valve I got).
So when I go back tomorrow I'll pick up a sprinkler valve and either a new 2" chamber pipe or some pressure rated 3" couplings.

Thanks again for your help.
I'm still open to suggestions etc. guys.
Wish me luck.

I think the PVC joing/couplings are supposed to be alot stronger than just the pipe. So you should be good.

I am also building my first Pneumatic, And I am also having a valve delima.

My Plans:
-BARREL: 48in(4ft) 2" Aluminum Barrel (1.75" ID)
-CHAMBER: 3ft 2" SCH-40 PVC
-VALVE: Modified 1" Sprinkler Valve or Stinger Valve

Im really wanting to know which valve I should use, and what distance I would get with this setup.
This is a C:B ration of 1:1, Right? I want to get the most/best shots out of my 20oz CO2 tank. If I need to change my ratio please tell me!

Sorry for hijacking your thread, They have simialr questions.

The 3" end cap is pressure rated but no other 3 or 4" connector parts at Home Depot are... yeah I know, bummer. The way I would go with 3" is an inline gun and use a 3" coupler and 3" to 1.5" reducer bushing. These aren't pressure rated either but because of the way they connect, they are really sturdy. Use primer and LOTs of PVC cement when glueing the parts together..really slop it on there. Give it at least a full 24 hr day to cure before you pressurize it.

Going with 2" would allow you to build an over and under gun...and a lot more pressure rated parts options.

DrowningTrout wrote:I think the PVC joing/couplings are supposed to be alot stronger than just the pipe. So you should be good.

This is definitely NOT true. Even if you use pressure rated couplings a lot still depends on you properly cementing things together.

Darn, well if that's the case I guess I'll be looking for a nice section of 2" after all...
So does the sprinkler valve just screw right on to the PVC thread adapter? It seems almost too easy.

Yeah, 1 inch threaded pvc. It really is easy.

My local Home Depot didn't have a 1" Orbit Water Master so I bought a Lawn Genie with a guide rod. It doesn't work. Is this not a good valve to use?

jimwilkins wrote:My local Home Depot didn't have a 1" Orbit Water Master so I bought a Lawn Genie with a guide rod. It doesn't work. Is this not a good valve to use?

its not your thread so dont go offtopic majorly.

yes its fine, look for a sticky called how to mod the wrong type of sprinkler valve or something like that

It's my son's thread. I'm trying to help him complete his project by tomorrow.

Alright, I ended up buying a Rainbird 1" which works perfectly. I'm really pleased with the way it turned out, I'll definitely get some pictures of it in the Pneumatic Showcase once I finish the aesthetics.

jimwilkins wrote:It's my son's thread. I'm trying to help him complete his project by tomorrow.

Well how was Carlman supposed to know that?

For future reference it would help if you explained your situation first, because believe it or not other people do use this forum.


@undueplum,

Sounds good, looking forward to the pictures.

Excuse my dad by the way, he's new to internet forums

undueplum wrote:Excuse my dad by the way, he's new to internet forums

It's okay, just don't want anyone getting offended.