New Water Gun Question

[eternal46845]

Hello all, I stumbled on this website a couple days ago while researching how to build a water gun. I wanted something big, unique, and able to completely soak the boys in my Cub Scout den. I think I found the right website

Anyway, I've got a gun designed...backpack with pump-action...anyway, what I am having issues with is the trigger system. Most people seem to use ball valves, but I'd perfer something a bit faster, more like a store-bought gun. I have a modified sprinkler valve from a homemade paintball gun. While its designed for air, its original design was, of course, water. In reading the forums and pages here, I found a tidbit that says that there would be turbulance in the water outflow, hence decreasing performance. But by how much? I'n not going for 60ft shots...just rapid fire maybe 20-30ft shots. Just enough to blast any kid that gets close. Would the sprinkler value still work for this?

[Ben]

Welcome to SSC!

The sprinkler valve would work if you don't want high range. But it will very noticeably reduce your performance here. The flow isn't as high as a ball valve and the path the water takes isn't straight, so it's not an ideal valve at all.

Ball valves aren't significantly slower than trigger based systems aside from some brands that make PVC ones. The ones with red handles you should avoid. If you want to increase speed of a ball valve, you could lubricate it or attach a torque arm.

If you buy some pulleys and wire rope you can make a trigger actuated ball valve too. Loads of options here.

[eternal46845]

Trigger actuated ball valve. Sounds interesting. Would ya happen to have a link or two so I can research this a bit?

[Drenchenator]

I made the only real example of this. The topic is here. It worked, but I do recommend something. The wire attaching to the arm must be parallel to the direction of action. In other words, if you want the arm to pull back, make the wire pull back directly in that direction. I didn't do that as evidenced by the pictures.

You also have to worry about closing the ball valve, which I thought would just require attaching a spring to pull it, so I didn't really plan it fully; thus I didn't get it close. The correct spring in the correct position will close the valve though.

My last tip would be to avoid large size ball valves for this, 'cause they are much harder to open and the system is complicated enough as is.

Edit: Though a lot of the problems I encountered arose from the size constraints I had: I really had to make sure all the stuff fit into the pipes!

[Ben]

Making a ball valve trigger actuated is intuitive, so I don't think any research is needed. Just get a spring, rope/wire, a few pulleys, and a trigger of sorts. Arrange them so that the trigger is positioned where you want it, and you're done. Use a rope/wire to avoid the problem Drenchenator had, at least partially. If you want a drawing of how I would do it, I'll see what I can do later tonight.

Here's a few links I found quick in Google:

http://www.sentex.net/~mwandel/cannon/air_gun.html
http://www.instructables.com/forum/T...ve-air-cannon/

Both of those links are for air rifles.

[Silence]

Sorry for the late reply.

If you don't want to use a ball valve, you could definitely build a pull valve, which is what many Super Soakers use.

I've attached an image of a simple pull valve. It uses 3/4" pipe, a 3/4" tee, two 1/2" to 3/4" bushing reducers, and 1/2" pipe. The seals are the same size as the pump seals since they fit into 1/2" pipe.

[Ben]

I'm not seeing an attachment. You must have forgotten it.

[Silence]

You're right. I've added it now though. Thanks!