Rain Bird 1" Inline Valve Question

[TheLost]

Hey guys,

I've been making air cannons for awhile, from overpowered nerf shooters, to full size football launching monsters, but I've never dealt with Electronic Valves before, so here we go.

I'm currently building a shoulder fire system, and wanted to run an electric valve, as opposed to a ball valve, which destroys accuracy due to having to crank on it.

I picked up a Rain Bird 1" Sprinkler Valve, and was wondering, is it really as simple as attaching the tank to one end, the barrel to the other, hooking up the wires to 3 9V batteries and a switch, charging with air, then hitting the switch?

It just seems like the valve has a lot of internal resistance, like, when I activate the switch, and blow (from mouth) into the "in" side of the valve, air barely pushes through, and I feel like this will cause rounds to just plop out the barrel, or not even reach that point.

Thanks, guys.

Lost.

[jrrdw]

Rainbird sprinkler valves wont really work right untill you operate them with at least 20 to 30 psi. This amount of pressure is not only needed to completely seal the diaphram but to open it fully as well. These psi numbers will vary but are a good working science / rule of thumb.

Welcome to Spudfiles!

[TheLost]

Thanks! I appreciate it! I'll be putting her together today, so I'll report back when I'm done. Thanks for the warm welcome!

[Boomer58cal]

Welcome to spudfiles.

Yup its pretty much that simple.

At some point someone will suggest modifying the sprinkler valve for pneumatic triggering, well it might as well be me. I'm not saying you shouldn't use the electric option if that's what you want, it's just that everyone I've seen modify a sprinkler valve pneumatically has never gone back to electric after that. The power increase is significant.

And trust me, if you put 100 psi behind a modified sprinkler valve, it will easily out-perform whatever ball valve you were using previously.

The main problem with using a sprinkler valve electronically is that the valve opens very slowly. This is because the pilot hole is so small.

Oh and we like pictures and videos. Hint hint...

[TheLost]

I'll get on those pictures

I opted to go pneumatic, drilled the top out, filled the pilots in, and ran in my blow gun… Only one issue… it was leaking… profusely.

So my cheap solution? HOT GLUE YAY.

I ran a good bead along the inside edge, then tightened the nipple a little more. Then COATED the outside with it… ugly but it works.

Now the bleeder is leaking *facepalm*

I'll tackle that tomorrow.

[jackssmirkingrevenge]

If it's stupid and it works, then it isn't stupid

[Boomer58cal]

If it's stupid and it works, then it isn't stupid

Truer words were never spoken.

[TheLost]

Well, I got fed up with it.

I disassembled the whole valve, de-glued it, and went back at it with some two part epoxy I had lying around…

Much better

Absolutely zero leaks, but I did have to trim the spring down since it was way too compressed in the valve (due to the nipple), making the diaphragm only open for a very short period of time, leaving a lot of air in the tank.

Now she is perfect, for me at least.

Charges to ~120 Psi, all air gets dumped on a single squeeze, and no more fog horn noises.

Going to use a poor man's chronograph tomorrow to find my muzzle velocity. (Range formula from Physics.)

range = Velocity(initial)^2 x sin(2Theta) / Gravity

My last cannon fired a 2 pound wooden slug at around 62 m/s, on a two inch barrel, with the air tank being 1:1 with the barrel.

[Boomer58cal]

On the first sprinkler valve I modified I had to trim a little off the plastic piece in the center of the diaphragm to allow it to open all the way. I messed up and screwed the brass fitting in a little too far and epoxy the heck out of it. That fixed the problem.

Glad to see you got it working

[Brian the brain]

If it's stupid and it works, then it isn't stupid

Ha!

I work, yet I'm..no...wait...



Good to see you've got it working...

Better than a ballvalve huh?

[TheLost]

It is worlds better.

My teacher had me shoot my nerf pocketball out of it down at the football field... Stood ten yards behind the endzone, shot at a low angle through the uprights, and it landed at the other 70 yard line. So that's roughly 90 yards, 270 feet, on roughly 100-110 Psi. I'm pleased as peaches, especially since it has a Tank:Barrel ratio of 1:1.

[Boomer58cal]

I'm glad to see it all worked out for you.

Be careful... spud guns are like potato chips, you can't just have one.

Or you'll go mad like I did and build something like this...

[TheLost]

I plan on keeping all my stuff shoulder fired

But I do have a fantastic idea for a milsim Rocket Launcher, as I am an Avid Airsofter.

[Boomer58cal]

Yeah I fired it from the hip.

I'm also building a backpack powered airsoft machine gun. Maybe we'll meet on the field of battle some day

[TheLost]

The only problem is...

I run an HK417, that I've completely overhauled the internals on...

6" groupings at 300ft.