Douchenator.

[CAPTAIN Nate]

Does anyone know how to build a Douchenator?
If so please tell me. I really want to build one. Plus my Tech Ed. Teacher said we have to build something that uses air pressure by the end of the month. I'm doomed!

[joannaardway]

*Groan*

You're lucky I'm listening to my favourite metal band (Nightwish) otherwise I would find a way to e-mail you a drop-kick.

Everyone here knows how to build a Douchenator, and many have them.

The Douchenator guide is all over the internet - type "Douchenator" into any search engine and copies of Duxburian's original article turn up.

Head off to http://www.soakermedia.net/water_balloon_launcher.php

There are more impressive air pressure devices around, but if you just need something very simple, then this is fine.

Now, Repeat after me: "I will use Google before asking a silly question"

[CAPTAIN Nate]

Thank you very much!


CAPTAIN Nate of the 501st Legion 1st Merc. Division
Signing Out

[Tactical Theory 101]

I have one question though. Does it recommend we should buy the pieces off the net or from a hardware store or something?

[Silence]

In the future, try not to bring up ancient topics, as the original posters usually are no longer active. Also, generic water balloon launcher questions could probably go in the stickied topic at the top of this forum.

In response to your question, it doesn't matter where you get the parts from - Home Depot, Lowes, McMaster-Carr, Ferguson, Ace Hardware, and some-store-whose-name-is-on-the-tip-of-my-tongue-and-begins-with-N all come to mind. Just make sure you get the right piping and fittings - ie, pressure rated.

[kborissov]

Will the Douchenator preform better if you build it with a 3" ball valve?

[Silence]

No. Or probably not.

The problem is that ball valves are hard to turn, and it only becomes worse as you increase the size. If you could open a 3" ball valve quickly, it would work well. But it would probably take at least 500 ms (milliseconds) to open it completely. When you consider the amount of time it takes for the balloon to exit the barrel (definitely no more than 100 ms), it becomes clear that if there's any air left by the time the valve is completely open, it will leave long after the projectile has.

Ball valves are great for water guns because flow is the most important factor there. However, ball valves don't work well in launchers because flow and opening time are important. That said, if you hook up a really powerful valve, the air stream and/or acceleration will shred the balloon to pieces. So the best solution is a mediocre valve in a long barrel.

[Drenchenator]

Having seen 3" ball valves at Lowes, I can tell you that they won't help at all in a pneumatic launcher. They are massive blocks of white plastic. A good twist isn't enough to open them; you have to use both hands--one on the handle, one on the valve--and even then it creeps open. Pneumatic launchers need valves that push out a lot of air quickly, and ball valves open far to slowly to accomplish this.

[C-A_99]

The best valves for launchers are pull valves, which require some building, and modified sprinkler valves, which, as the name implies, require modification. The pull valve is the cheapest, while the sprinkler valve is faster but is also borderline since it has been known to burst balloons in the barrel before.

The easiest method is using a 1" or 1 1/4" ball valve with a good torque arm attached. This gives it a slightly more acceptable opening time, but the problem is that having to slam that arm down fast is impractical when you have to aim the launcher. (unless, perhaps, if you place the launcher on a cart) The pull valve is probably the best method, and some of us could draw a basic design if necessesary. However, I've never built one and don't know how to get everything together. Heck, I didn't even modify my sprinkler valve yet for my new launcher.

A word on the Douchenator. I'd strongly recommend going with an over-under design than having to carry around this cumbersome thing. I built one myself that was pretty much full length: 3ft long barrel and 2ft long pressure chamber. 1ft for pressure chambers should be plenty, while 3ft is a good length for the barrel. My Douchenator stands about 6-7ft tall, and kickass as it may look, it is not fun to carry around, especially indoors. Going with an over-under design requires only 2 more fittings and a little more PVC, without really changing the performance of the launcher. (which I actually thought it did when I built mine)

[cantab]

Doesn't the modification to sprinkler valves end up making the opening even faster? As well as changing it from electrical to pneumatically operated or something. So an unmodified sprinkler valve might be better for a WBL.

Also, sounds like this is in part a school project or something. If it's anything like what I've had, they'll want to know "how would you improve it? what would you do differently next time?" sort of stuff. So it may be better to deliberately not go with an optimum design, otherwise you're gonna be stuck there. A ball valve with a big torque arm could be adequate.

[C-A_99]

Unmodified, its too weak and prohibits flow. Also, getting the circuitry hooked up doesn't sound fun either, especially when water's involved. Best solution is either the ball valve with torque arm (cheapest and laziest), a pull valve, or a modified sprinkler valve.

As for Nate's school project, that was nearly 2 years ago; check the posting dates.

[Silence]

Modifying a sprinkler valve does convert it from using solenoid (electrical) to pilot valve (pneumatic) actuation. Believe it or not, pneumatic actuation opens the valve faster, which is why the mod is done in the first place.

Unfortunately, if the valve is opened too quickly, the balloon will burst. So it's probably all the better that the launcher stays electrically actuated, as long as you insulate the wiring with electrical tape. These are used in underground irrigation systems, after all.