Water Balloon Crossbow

Leprechaun71588 · Post by **Leprechaun71588** » Mon Feb 21, 2005 2:16 am

Hey everyone, I'm getting back into water warfare after a long winter. I've had this idea of a water-crossbow launcher-thing for awhile now, but I never really had the money to go out and buy the parts.

I got the idea a few months ago when I was working on building a trebuchet (an advanced siege weapon much like the catapult) for school. I was checking out different websites when I found a weapon that looked like a giant, mounted crossbow, that fired rocks/tennis balls and stuff.

My version is a lot less complicated and is made of just stretchy-cord thingies and 2" PVC and some glue and screws I had lying around my garage.

The pieces I bought only cost me about $11 and it took about 2 1/2 - 3 hours to build.

I haven't gotten to really test it out yet, I still need to make some kinda of trigger. I pulled it back as far as I could get it while trying to hold the water balloon and everything in place at the same time, and it got about 10-15 feet while I was sitting.

Side view: http://www.geocities.com/leprechaun7158 ... w-side.jpg
Front view: http://www.geocities.com/leprechaun7158 ... -front.jpg

Jadefalcon09 · Post by **Jadefalcon09** » Mon Feb 21, 2005 5:16 am

A very creative idea and approach to using a water balloon. Please do post back when you are done with this. It it has good range and accuracy, you may have actually sparked corporate interest, or beat Nibor's homemade Water Balloon Launcher. Your design is genius and brilliant. KEEP WORKING AT IT!

Spinner · Post by **Spinner** » Mon Feb 21, 2005 9:27 am

Hey, nice to see you back again. I had an idea like this quite some time ago, but I never managed to build it. It's an interesting idea, but I'd have thought you'd need more powerful cords than what you're using right now, or at least a longer stretch for them.

As for a trigger, tricky one...not sure what to do there. Unless you could attach a piece of cord to the back of the balloon receptacle and pull it through a hole in the back of the weapon? That might be the first step.

SSCBen · Post by **SSCBen** » Mon Feb 21, 2005 3:11 pm

Trigger? Just take a metal rod, remove the bungee cords, pull the center ring up to the top, hold it steady and drill a hole slightly larger than the metal rod straight through both sides of the PVC. That will be more complicated than I said, if you have trouble doing that, I'd recommend drilling the holes separately. All you'd have to do after that is pull the metal rod out from the hole to release the balloon. I'd also recommend bending the metal rod so you could pull it out easier.

If you're looking for a little more power, try adding a few more bungee cords. However, always practice safety and don't underestimate their power.

Leprechaun71588 · Post by **Leprechaun71588** » Mon Feb 21, 2005 4:50 pm

Well I got a few test shots in this morning, and to make a long story short...it wasn't too great. At best, I think I was getting 20 feet. I tried hooking the cords on in different places so they would have more tension when they were pulled back, but it still wasn't helping too much. It just made it harder for me to pull back.

I've got a couple ideas on how I might do the trigger, so I'm going to go get the stuff today along with more of the bungee cords. I'm not sure if I'll be able to test it out again today with the stuff, but I should have it done by tomorrow.

I guess 20 feet isn't too bad for the first test shots ever, but I really would like to improve it to at least 80 or 90+ feet. Otherwise it's just easier to manually throw the balloons.

NiborDude · Post by **NiborDude** » Mon Feb 21, 2005 6:40 pm

Wow! Thats a really cool WBL. One thing I'm concerned about is the water balloon staying in the PVC. It looks like it could just fly out and maybe even backfire.

wetmonkey442 · Post by **wetmonkey442** » Mon Feb 21, 2005 6:54 pm

Unfortunately, you will never achieve the same results using material tension as you would using air pressure, although the concept is unique, and a lot easier to use than an air powered design.

soakup · Post by **soakup** » Mon Feb 21, 2005 9:57 pm

I think that maybe if you could find some way to make the baloon spin when launched it may go further my idea for this is to twist the bungee around also for a trigger get a relatively small piece of wood maybe 8 inches long and get some two to three inch nails and put them in the wood(maybe six) and this will allow you to adjust strength then nail a very small nail or piece of wood to the bottom of the front after doing so cut a large hole in the main half pipe thig and drill two holes in the side then place the wooden contraption in so that the nail or whatever you used on the far end is in the back of the big hole then nail into the main piece of wood through the drilled holes and you have yourself somewhat a trigger.

Also wetmonkey is right and your idea won't achieve to be as good as air pressure and your idea is much like the water baloon slingshots.

Leprechaun71588 · Post by **Leprechaun71588** » Tue Feb 22, 2005 4:57 am

Soakup....I have no idea what your trigger is supposed to look like. It sounds really complicated and not too sturdy, but maybe that's just me. The thing is supposed to work just like the waterballoon slingshots, that's where I partly got my idea from. I had 2 slingshots, but they really, really, really sucked. They shot maybe 15 feet at the most, making them completely useless.

I went and got some more stuff for the gun today. I tried out 3 bungee cords on each side, but it was too hard to pull back. I kept two on, and it's still hard, but I can get it to shoot somewhere between 20-25 feet.

I'm still not sure how exactly to do the trigger. If I put it through the bottom, the little sling/cup thingy pops out. Most of my other ideas seem like they'd be too flimsy to hold back all that pressure. I've got a couple old bicycle brake parts that I'm going to try to figure something out with. Right now I'm more worried about getting it to shoot good.

I tried drilling a hole in the back of the cup and then putting a rope through it so I could pull it back easier, but that idea didn't work too well either.

My hands are pretty sore and cut up from pulling back the bungee cords so many times and cutting myself on the yet-to-be-sanded PVD edges. So I'm going to stop for a couple days and just do some research and come up with more ideas.

Spinner · Post by **Spinner** » Tue Feb 22, 2005 12:27 pm

Originally posted by soakup@Feb 21 2005, 09:57 PM
I think that maybe if you could find some way to make the baloon spin when launched it may go further my idea for this is to twist the bungee around also for a trigger get a relatively small piece of wood maybe 8 inches long and get some two to three inch nails and put them in the wood(maybe six) and this will allow you to adjust strength then nail a very small nail or piece of wood to the bottom of the front after doing so cut a large hole in the main half pipe thig and drill two holes in the side then place the wooden contraption in so that the nail or whatever you used on the far end is in the back of the big hole then nail into the main piece of wood through the drilled holes and you have yourself somewhat a trigger.

Also wetmonkey is right and your idea won't achieve to be as good as air pressure and your idea is much like the water baloon slingshots.
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I gave up trying to make sense of that after a while. The long run-on sentence made it very difficult to understand. I think you may have already been told not to do this, so don't! If you're post isn't comprehensible, we'll neither be able to give you credit for what you've worked out or suggestions on how to make it better.

One more offence, and it's Read-Only for 3 days. I'd rather not have to do that, so please do your best in this regard (and others) from now on.

soakup · Post by **soakup** » Fri Feb 25, 2005 11:00 pm

Hey laprechaun maybe you may want to see this it may be of interest to you

http://forums.sscentral.net/index.php?showtopic=360&hl=

Edit: Leprechaun is first spelled correctly above, and corrected in the spell check.

I don't see how you could spell that incorrectly.