SpudFiles

This valve
http://www.sprinklerwarehouse.com/detail.aspx?ID=140
is going to be delivered to my house soon, and I was looking to mod it for pneumatic actuation. I know that I can probably put the 1/4" NPT through the bleed valve, or as shown here: http://www.duke.edu/~jwc13/tennisball.html

Either way, I was wondering if a blowgun would have enough flow to open the valve quickly. The Wiki vaguely mentions that 1.5" and above valves will need something with more flow, but neglects to mention the alternatives.

I was thinking a 1/4" NPT ball valve?

A blow gun would work way better than the solenoid. A 1/4 inch ball valve would work even better than that, and a 1/2 inch ball valve would work even better than that.

EDIT- so here it is for you math junkies out there.

solenoid < blowgun < 1/4 ball valve < 1/2 inch ball valve

Thanks that makes good sense. I'll post pics in a showcase when I finish it the cannon.

It never occurred to me that they made vales that large. Care to give a preview of sorts? What is the size of the barrel going to be and what do you intend to shoot?

Sure.
So far I have two chambers, each 3 feet of 3" pipe, and then on the end of each a set of 2" elbows. The tanks join together through a tee, and then the tee goes to the valve and then barrel, much like this cannon

http://leckemby.net/spudwerx/spudchucker1.html

only with the 2" sprinkler valve. EDIT - and pw fittings

Haven't thought much about ammo, but i did buy a section of 2.5" pipe for tennis balls, and a 1.5" pipe for potatoes, etc. and I might invest in a golf ball barrel (If I do, what are the best sizes?).

This cannon is my third overall, and I'm making it just to have a large cannon thats somewhat portable. I thought that the 2" valve would give it good airflow for more power.

Also I was thinking of painting it . . . what color would be cool on a cannon? I thought definitely purple.

And maybe a silencer?

I'm open to ideas.

black chambers and a dark red barrel, that would be (sic). 1.5inch sdr21 sleeved in 2 inch sch80 (yes, those are somewhat exotic pipe) fit golf balls. you don't need a silencer because it wont be very loud.

Mega_swordman- they make 3'' sprinkler valves, but they are expensive and not worth it. jssizzle was smart to only buy a 2'', the 3'' are over $200

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This cannon by Foxx uses a 3/4" valve to actuate the 2" valve... very nice, I'd suggest considering a setup like this: http://www.geocities.com/cain333_2000/c ... vlvmod.htm

Thank you all for your suggestions.

I'll probably start with a 1/4" ball valve, and then maybe a 3/4" sprinkler after judging the performance of the ball valve.

I figure the performance difference between the 1/4" ball valve and the sprinkler wouldn't be noticeable enough to get more "Ooooh"s and "Ahhhh"s out of my friends, but as many of you know having to turn a ball valve every time to fire can be fatiguing.

We'll see.

Black and red would be cool, thanks hi.

As for the golf ball barrel, I don't really want to buy all that pipe (I would have to order it at mcmaster I guess) and sleeving? . . . I'm to lazy. Any alternatives to the sleeved sch. 80?

I bought and modded a 2" Nelson valve. I yanked out the flow control and put 1/4 fitting in its place. There is a medal rod that passed through the diaphram from the flow control that i discarded. I plugged the small hole, the solenoid was removed and plugged, and a small port with a tiny o-ring that vented to the out take (don't know what it did). I'm using regulated CO2 and when I attempt to pressurize it air leaks out the barrel (sounds like a tuba). I've sunk a few hundred into this project and I'm reaching a breaking point, assistance would be appreciated.

For that price why not make a piston valve?

I started to work with a sliding piston/bolt but it didn't look as durable as a commercial irrigation valve.

I just got the valve in the mail today!

I took it apart and was looking at it, and now can't decide where to tap it. I would tap it through the flow control on top, but the hole is to large for a 1/4" NPT to hose adapter. So I thought about modding it like the one on this page:

http://www.duke.edu/~jwc13/tennisball.html

but I can't totally figure it out. It looks like he drilled into the solenoid port, but he would have to plug the hole where the solenoid goes to do so. Confusing? its kinda like this:



If I tapped in there, then I would have to make the place where the solenoid screws in airtight, like in the picture on the webpage. How I would go about doing that is beyond me. To big of a hole to epoxy. So I thought about drilling into the main top part of the valve like you would with most valves, but the hole would hit the flow control which cant be removes because of a spring yadda yadda yadda etc.

Help/Ideas?

Sorry about the long post.

Nah, you can epoxy that solenoid hole with no problems. Just use enough of it

Hmm.

You realize that the hole to fill is the big one, not the small one right?



the red one.
Its like 3/4 inch across . . . with epoxt? I was thinking maybe a piece of plastic and epoxy . . .

I'll try something.