Water Rocket Launcher

Leprechaun71588 · Post by **Leprechaun71588** » Fri May 26, 2006 10:50 pm

This is an idea I've been thinking about for awhile and finally had time to really design and build. My design isn't made so much for water fights as it is for being a cool toy to play with.

The idea came mostly from a toy I used to have when I was younger called a Water Rocket.The idea is that you fill the rocket up about halfway with water and then use the air pump to pressurize it. When you have gotten enough pressure built up, you release it and the rocket goes flying off into the air about 30 feet or so.
http://www.paulsslides.com/images/water ... kitpsd.jpg
EDIT: The more modern version would be the Monster Rocket. Kinda forgot about that since I've never actually used/seen one.

When I tried looking those up, I came across a couple different websites that talked about people building homemade water rockets that fired much better than the old toys. Ones that go hundreds of feet into the air. Here's one such site:
http://www.outsideconnection.com/rockets/

So I came up with a design to fire much smaller and safer water rockets at an angle from a holdable launcher.
http://www.geocities.com/leprechaun71588/003.jpg
http://www.geocities.com/leprechaun71588/002.jpg
http://www.geocities.com/leprechaun71588/001.jpg

Right now using one of those 12 oz. Coke bottles, I am getting a good 50 ft. or so. However, I'm waiting for the glue to finish drying on one which I modded with a smaller nozzle and fins which should make it shoot much further. I'll post my results with that tomorrow after I get to test it out.

Keep in mind also that I'm not pressurizing it as much as I could. This is more or less because of safety reasons. I haven't decided on a good trigger build so I'm still pulling the thing to release it by hand. Also, with just a normal bottle, there is a significant amount of water leakage from the bottle as it is getting pressurized. It is hard to make it loose enough to be able to slide on and then fly off while still being airtight. I think that my design for the actual bottle-rocket solves this problem.

Tomorrow I will get more pictures and maybe a video up if I can.

Silence · Post by **Silence** » Sat May 27, 2006 4:05 pm

Wow...that's pretty interesting, but it seems very much like Nerf. I know it's possible to fire airsoft pellets using certain commercial soakers' nozzles, but doing it is just a waste of effort. This, on the other, hand, is a reasonable setup.

Yeah, you really need some type of locking mechanism that allows you to build up reasonable pressure and then release the bottle. However, it's a good start, and it's nice to see somebody who builds something and then talks about it (unlike me)

. I'll be thinking about some type of trigger mechanism...

Leprechaun71588 · Post by **Leprechaun71588** » Sat May 27, 2006 4:22 pm

I've actually got a thing now that holds it in place while I'm building up pressure, the problem is just having a way to pull it off when I'm getting ready to launch. I've got something I'm gonna try out today when I have some time.

I tried out the modified bottle and it didn't seem to make a ton of difference. The biggest difference I noticed was that on a normal soda bottle, it would make a 'thunk' noise as it flew off, and the one where I made the nozzle smaller went with a 'phsssssssst' sound. I think the modded bottle was releasing it over a longer period of time, which should have made it go farther or faster, but I had to add some weight to the nose to keep it going straight so that just took away from any extra power I got from the smaller nozzle.

Right now the two things I really need to figure out are
1-the right kind of bottle/rocket to use and
2-getting the trigger mechanism on.

Shouldn't be too hard, all I really need is time to test and retest, which I have a lot of now that summer is here.

powersurge919 · Post by **powersurge919** » Wed May 31, 2006 5:30 am

OMFG Ive tried this but gave up. i have a perfected
warhead desing for these rockets mostly for 2 liter bottles
and they launch by a mixture of water + air pressure
in the bottle its self and try to use some fins for straight
flight. ive never put these on a gun launcher though ive
just held the rig out and pulled a string that secured
it to the plug on the rig.

jkpaint39 · Post by **jkpaint39** » Sun Jun 04, 2006 6:32 pm

I no this isnt the buy/trade section but make when u perfect it ill probobly buy one from u for $35-$40

Adhockeykid · Post by **Adhockeykid** » Sun Jun 04, 2006 6:53 pm

jkjp39-learn grammar! it is impossible to read your posts.

Lightbulb41 · Post by **Lightbulb41** » Sun Jun 04, 2006 7:11 pm

Great Idea but what would it be used for in battle? I still don't see a point in Water rockets unless you can fire a balloon at them.

wetmonkey442 · Post by **wetmonkey442** » Sun Jun 04, 2006 8:35 pm

I love how these topics that are actually relevant get immediately hijacked by 3 year olds. Ben, you seriously need to take care of a few people here.

As far as the water rocket is concerned, nice design. I've always liked water rockets, but have never gotten the chance to build one myself. However, I have heard that fins will help to make it go straighter.

I like the way you attached a reservoir onto the gun. It looks vaguely like an RPG or something similair. Nice work, and please post more pictures if you get them?

Hunt_and_Annoy · Post by **Hunt_and_Annoy** » Sun Jun 04, 2006 9:45 pm

Very interesting...maybe some application in paintball?

Airpi · Post by **Airpi** » Mon Jun 05, 2006 8:41 pm

Looks great, but Im just going to repeat everyone here and wonder at a practical application for it.
*wonder*

Leprechaun71588 · Post by **Leprechaun71588** » Tue Jun 13, 2006 11:25 pm

Here's a video of me firing it. I think it could do much better but I just need to improve the rocket.
http://us.share.geocities.com/leprechau ... CF0008.AVI
EDIT: I'm coming up with some data transfer error now when I click the link, so if you know of a better place to post it that would be great.

And in case you're wondering, the spiffy looking sunglasses actually served a purpose other than looking cool. Observe:
http://www.geocities.com/leprechaun71588/intheface.bmp

Silence · Post by **Silence** » Tue Jun 13, 2006 11:43 pm

Yep, Geocities returns an error stating that both links are currently unavailable. For video files hosting, I'm pretty sure a lot of people use Putfile. I don't think it's the best place out there, but it's a popular site that you should try.

guerrilla91 · Post by **guerrilla91** » Wed Jun 14, 2006 12:16 am

I think the rockets idea is a good one, and it would be very easy for me to make (I did the water rockets event for Science Olympiad). My rockets went hundreds of feet high at only 60 psi. The rockets I built used two liter bottles, and had working parachutes. Maybe my parachute one could be used as a sort of "air drop" of supplies.

joannaardway · Post by **joannaardway** » Wed Jun 14, 2006 1:47 pm

I can see ways of making these battle practical.

A balloon warhead, so that the thing is reusable.

A "soft" (as in not super tough, rather than "soft drinks") plastic drinks bottle so that impact is safe - etc.

A pre-pressurized tank to dump air in immedately.

In fact, I was launching bottles like this from my 18mm bore launcher - the bottle neck fits over the pipe perfectly, so it worked quite well.

Helluva lot of recoil though.

So 3" pipe to hold the bottle in place, with 22mm OD pipe running the length of the bottle. (you want to dump air in for as long as possible)
In fact, run the 3" pipe out further than the bottle's length to reduce "Splashback"

Damn, another thing I want to make.

joannaardway · Post by **joannaardway** » Thu Jun 15, 2006 9:35 am

I took my launcher out to perform some more tests with bottles.

The first launch I did went a clean 50 metres, rather further than I expected, and I lost the bottle in the process.

The second launch was done with fins, and I managed to totally soak myself with the water that shot out backwards. This one went less distance (20 metres), but the fins had some effect on stabilising it. However, the fins destabilised it quite fast after thrust had ended. This would be corrected by a better fins (these were made in 5 minutes from old cardboard), a weighted nose, better streamlining and a better bottle choice

After a change of T-shirt, launches with merely air were fairly successful, but these made a blast like hell cracking open.

Tests with injecting water instead of air failed - the flow of water through the valve was insufficent.

I concluded that more laminar flow from the bottle could only be a good thing. Thrust would be more stable, and the back wash would be better contained.

Maybe with a QEV, better stability, more pressure, and support walls for when the bottle is being fired, this might get somewhere.

I'll put together a prototype in a week or two, using what I can find.