Water Gun Challenge

[andreal]

Hi all - I'm new on here and I'm very impressed with all of the things I'm seeing. I am the Program Director for a Cub Scout Day Camp in Texas. Our program is in the heat of the summer and I'm in need of water guns that the boys can make to get each other wet to stay cool. Last year we did something similar to this design http://www.instructables.com/id/5-Water-Guns/ with a few modifications to get the price down to about $1.50/kid. They dipped the nose into a bucket of water to fill and then squirted each other. I need a cool new design for this year that fits the following parameters/wishes, and I'm hoping ya'll can help us out.

1. Design allows them to shoot a number of times rather than needing to refill from a bucket for each shot (see last year's design). We've been circling around using a water bottle, 2L bottle or something similarly cheap or free to use as a bladder.
2. the cost per gun (kid) needs to stay under $2.50 (ideally more like $1.50...and if it's super cool, we may be able to up that a tad). I only get $19 per child to entertain them for a week, so going over $2.50 is really a lot for a single activity.
3. safe for kids to use (ie: no sharp metal), we can help them with low voc pvc glue
4. Our Cubs are age 6-11, so it needs to be designed for their size/strength
5. able to refill easily, ideally w/o the help of an adult

I have the ability to purchase in large quantities, we'll have between 200 and 300 kids at camp this year, which gives some purchasing power to reduce prices. I *may* also be able to join with other camps in our council to buy even larger quantities to get things into our price range.

I know it's a challenge, but I'm hoping we'll get some suggestions from ya'll or even better, the design we're looking for. Even if the design goes over in price a bit, I'd love to hear it. We may be able to put our heads together to find alternatives or wholesale pricing, like I did last year in getting the $5 squirt gun (link above) down to $1.50.

Thanks in advance for any help or suggestions you can provide!

Andrea

[martianshark]

Will you have a hose? If so, something similar to Ben's 2L Homemade could be perfect. The pressure from the hose both fills and pressurizes this gun, making it very fast and very easy to refill. And all you need to build it is a soda bottle, a garden hose nozzle, and a few fittings and tubing.

Or, maybe you could make a large tank full of highly pressurized water, and have lots of hoses connected to it so that multiple scouts can use it. Several of these could be made, and maybe each tank would be a team of players. You could put wheels on the tank to make it mobile.

Or, if you have enough hoses, you could attach some hose separator fittings to it so that multiple people could use the same hose.

Or, you could go to the dollar store and get some cheap piston guns similar to the ones you made last year.

Or, you could just make lots of water balloons.

Where's the blasters from last year? Did the kids take them home?

One more thought: If you recommend to the kids to bring their own water guns, the amount of blasters you have to make could be reduced. If you do this, tell them to get Water Warriors guns. They're the best.

[marauder]

I'm thinking that it wouldn't be too difficult to make a simple piston based soaker, using a 2L bottle for a reservoir. Something like the Bottle Shot: http://www.isoaker.com/Armoury/Analysis ... eshot.html

I don't know how much Bottle Shots sold for, but I remember buying a Vaporizer for $4.74. Considering all the extra cost due to an external shell, different colored plastic, screw on cap, middle men, etc, I'm sure something like this could be made for around $2.50.

Someone see if you can come up with something based off of my idea. I wish I was at home, I would draw something up for you using a few hardware/home improvement supplies, but I'm out of the country until this Fall. BSA means a lot to me. I grew up on watergun fights at Camp Raven Knob, NC in the Appalachians. I'm an Eagle Scout and I'd like to be a Scout Master one day when I'm older. Good luck with things!

[HBWW]

With something as durable as PVC water blasters (even cheap ones), this is definitely better off as more than just a one-time thing if possible, even if the blaster ends up being low-cost.

Now, I think it'd be great if you could stretch the budget to around $4 per unit, and that would allow you to build a basic but remarkably powerful air pressured blaster. However, that's a far stretch, so I'll throw in some other ideas.

- (Requires hose) A blaster similar to the 2-liter homemade listed above. All you really need is:
> Special hose/faucet connection for quick connect/disconnect
> 40 to 80 latex party balloons (12" balloons are good), stacked over each other to form the pressure chamber.
> 1/2" barb to 1/2" threaded fitting
> Hose/tube clamp
> 1/2" threaded ball valve
> Connections from ball valve to nozzle and/or quick connect/disconnect fitting. With a little improvising, you can probably get both to work from here. The idea is that to fill the blaster, it is connected to the faucet/hose and the ball valve as well as faucet valve are both opened. Once full, the valves can be closed and the blaster will shoot. The balloons storing the water may burst from letting the faucet flow too long into the blaster.

- (Easy, cheaper, and gets the job done easily and nicely): Gather up and give the following to each kid:
> Two small/cheap squirt guns. They all have about the same range anyway so get the cheapest ones. (Think multi-packs like $1 for a 6-pack.)
> Several water balloons (and a way to carry them. Backpacks are good, but you can also fashion water balloon containers out of Pringles/tennis ball cans, large plastic fountain drink cups, or simply store them all in a cache and force those playing to carry them all by hand)
> Several water bottles. Water bottles are perfect for refilling squirt guns as well as for close-range splashes and can soak a lot more than a squirt gun at such range.

The squirt guns can also be omitted since they do not soak much. They may be better off being replaced with the cheap/large syringe setup you used earlier. Water balloons are pretty cheap, and water bottles have to be saved up if possible. If not, it's not really worth bothering with.

Keep in mind that not everybody has to have one of everything, exactly the same, so long as everyone takes turns. i.e. of two teams, each one may share a more powerful blaster, a stash of water balloons, or whatever else may be in limited supply. This may not be ideal, but it gives variation and more possibilities.

Good luck with your project.

[atvan]

I second the 2L homemade. There are better ways to do it, but nothing can beat it in terms of simplicity and price. You can even use refreshment bottles from earlier in the week.

[martianshark]

A CPS gun wouldn't be a good idea. 6 year olds wouldn't know when to stop filling, it would be a lot of work to layer all those balloons, and it costs more than a 2L bottle.

[andreal]

So happy to see so many replies so soon! Thanks ya'll! Let me see if I can answer some of the questions posed:

We have a severe water shortage at camp, so there won't be any access to a hose. They are talking about installing city water prior to camp but this was discussed last year also, so I can't plan on that happening. We can have the fire dept come out to fill baby pools, which they could dip water bottles into for refilling (not drinking! lol), we can also beg local troops to use their water buffaloes, but those too are limited.

The water guns we made last year were taken home. We also bought them cheap piston ones which they played some water olympics with and also kept - we may do that again this year too. We're considering just buying some super soakers this year and letting them use them for just that session, but I really like to have them in their hands all day to stay cool and to teach them something. You know, give a boy a squirt gun, he's cool for a session; Teach a boy to make one, he's cool for a lifetime. I like to get their minds working and give them a sense of accomplishment too.

Ya'll are thinking out of the box for other activities - that's awesome! I didn't put this in the post, but we're considering some sort of water feature with a recirculating pond pump that lets the kids change the water flow and let it go through different tubes, ladles or spinning wheels, all moveable...they would be standing in a baby pool type of setup...can't help but be wet that way too. There's a couple other wild ideas floating around the idea of splash balls and pressurized air cannons, or a kid wash http://www.instructables.com/id/KidWash ... Water-Toy/ - but I'd need a pump/tank or maybe an elevated water tank or something, in order to get water pressure to run this...yet another thing to work out and cost issues. I welcome other suggestions!

Water balloons are tough due to the quantity we'd need. Kids have a hard time tying them off so it's left to volunteers to fill them and the sheer quantity required to accommodate 200-300 kids is really tough. Add the water issues above and it's just not feasible. I wish we could - I'd love to use those large water balloon sling shots that shoot them really far - or better yet some potato guns but with water balloons...FUN!

It's a challenge, I know....but that's also part of the fun for me. Fixing some problem that seems insurmountable. The ideas posted so far by everyone has given us more to think about...very helpful!! I'm jammin on the Bottle Shot design - just need to figure out the inner workings. I'm thinking the water bottle may need to be on top though, just because all that weight at the back of the thing might be an issue for the little ones. just a guess. I have the piston portion of the gun from last year's design, I just can't figure out how to adapt that to draw the water into the chamber from the water bottle. Can anyone give advice on that?

Thanks!!
Andrea

[martianshark]

To get it to pump water out of the bottle, you need two check valves of some sort. A check valve allows water to go one way, but not the other. Can someone find a picture of how this works? When the pump is pulled back, the water is sucked through the first check valve. When the pump is pushed in, the water is unable to go back through the check valve into the bottle, and is pushed through the second check valve and out the gun.

[DX]

The problem with making a full homemade with a pressure chamber is that it will go way over budget. One check valve alone will run you at least $5 and up to $10. A homemade check valve will still cost at least $3 and you'd need two of them.

If you go for a bottle shot type of design, you only need one check valve unless you're worried about leaking out of the nozzle when pumping. When you pull the pump forward, it draws water from the bottle through the valve and into the pump. When you push the pump in, the check valve won't let it return to the bottle. It also cannot stay in the pump, for there is now no room, so it must flow out the nozzle. If you're worried about water being drawn to the nozzle when pumping, you could use a vinyl tube connection to the nozzle. When small enough and angled the right way, water will only go into the pump when drawn, saving you the need for a 2nd check valve. However, this is a pump-action design that fires when you push the pump in. If you want the bottle to serve as a true pressure chamber, you'd need a hose. Anything else will go over budget. Two check valves definitely will.

Those syringe/piston-pumper style guns are your best bang for your buck. Nothing else you build in this price range will have nearly the same performance. A bottle shot design is potentially unreliable unless you go over budget. It is possible to have a reservoir on a syringe gun, but that requires 2 check valves. While they do need to be reloaded for every shot, one advantage is that they are being primed when reloaded. Your scouts won't waste any time refilling since they can shoot immediately after loading a shot.

The cheapest option there is, as mentioned by others, is the bottle with a hole drilled in the cap. You squeeze it and it shoots. There are multiple shots possible and refilling is easy to understand. The cap can also be taken off and the full neck used as a riot blast that soaks everything nearby.

I wouldn't think cheap dollar store pistols would work out because scouts will want to use the better soakers. Water balloons would be a hit, but obviously in more limited quantities. They could be useful to supplement the action, especially if range is severely lacking. Buckets are another option, however they are water-intensive and single shot.

Overall, I'd go with a mix of syringe guns, squeeze-bottles, and water balloons. These items will have the highest range and soakage with the cheapest costs. They also benefit the most from purchase in bulk, since syringe guns are mainly just PVC pipe that comes in long lengths, water bottles come in large packs, and water balloons come in large packs. Syringe guns and balloons will give your scouts long and mid range action. Squeeze bottles, while very short ranged, can dish out so much water that no one would really be disappointed. They can wait for a syringe gun to use its shot or a water balloon to be thrown, then rush in and unload, more than once.

[HBWW]

Water balloon launching, while fun, is very rarely ever useful for any games outside of target practice. We use pneumatic cannons, never combustibles which most potato cannons use. Water balloons can still be useful even if each team has a limited quantity of them, such as a bucketful of 50 as opposed to a large containerful of several hundred.

DX has the right idea on water bottles. They are very versatile and are a staple for water wars of all kinds, I even use them as mines by drilling two holes into them and laying them on their side on the ground. The standard hole-in-cap squirt bottle gets comparable performance to squirt guns too. As for the syringes, those too, are the best option for the price range. If you build a syringe that can directly pull water from a reservoir (instead of having to dip in a bucket), you might as well just create a pressurized blaster since a pump and valve don't add to the cost nearly as much as the check valves do.

I suppose the squirt guns are never a good choice except for very informal occasions. They're really nothing more than silly toys, incapable of soaking much at all and the only good part of them is the shooting aspect. I ought to use them as tiebreaker blasters for sudden death duels.

Aside from equipment, you also want to consider what games are being played around this. Is it just a soakfest with no hit rules? Chances are that hit rules are a bad idea for the age range you're working with, but even without hit rules you can still create interesting games. The classic (for me anyways) is CTF, where both teams have a specified area where they may hide their flag. You can also do single-sided games where one team is invincible and the other is eliminated if hit, then offset the invincibility by giving the best (and I mean the best) water weaponry to the vulnerable team. One game I sometimes have is a zombie apocalypse where the zombies are invincible but only have a water bottle or squirt gun and must go up against two hoses, high powered blasters, etc. Time limits are useful for controlling these games. The teams then switch off and take turns. That said, even these games are likely too elaborated for them to play, but it's up to you and the kids to decide. I'd imagine that they'd at least enjoy some sort of basic CTF game.

[andreal]

What about using one or two of these type of check valves?
http://www.usplastic.com/catalog/item.a ... id=redirec

Looks like I could get them as low as $.60 each plus shipping due to the qty discount. I don't know the required specs for PSI for this...seems like 150PSI is quite a bit. If I could get away with just using 1 and accept the nozzle leaking that would save even more $$, I just can't picture how to do that. I think it would be fine, they leaked out the nose last year too - the boys got the hang of quickly tipping it up to fire with no problem.

I can see how it would need 2 check valves, in order to create the vacuum that draws the water in and in turn forces the water out - just not sure how to fully implement that functionality yet. If we start from last year's design, I can see the 2 check valve system, but I can't picture in my mind how a single check valve system would work. I roughed up this design this morning. I'm estimating that we're at $3.44 per kid - probably slightly less, but I don't know how to attach that water bottle, nor do I know if this will work. Can I get your thoughts on it?



Forgive that things are not to size, I can't figure out how to resize the 2 longer pipes up front to appear 20" each in the PVC Designer software. The handle and smaller piece at the rear are estimated at 5" each. I'm concerned there's too much empty space inside the gun, though maybe that's resolved on the first pump or so, when the entire system is filled. It seems the more efficient design would have the 2 check valves closer together but I can't figure out how to implement that successfully (and in budget). last year's gun had a cork there. I don't know what we could use to plug that hole and hold a check valve. We were talking about using a rubber washer/gasket sandwiched between 2 metal washers this year (like in the instructables I listed originally) to plug that hole (screwed into "something"), because the #5 corks we used last year blew up into the handles of some of the guns. A #6 cork might fix that but I'm not sure if we could drill a hole thru a cork, glue in a check valve and expect that to stay in place. I figured moving the check valve all the way to the rear might fix all of that and save some cost since we're already well over budget on this. But there's a definite cool factor to what we're doing, sometimes it's worth going over on 1 activity just to blow their minds. And of course getting it down to a single valve system would be even better, cost-wise. There's also some question in my mind as to how to attach the check valves....right now all I can see doing is drilling holes for the barbs to stick through the end caps and somehow gluing them in place. (?)

We may be able to use the water bottle squirt guns that you squeeze as well, I'd have to run the numbers to see how cheap we can get that down to. What often happens is that their daily projects get taken home (or the chaperons tell them to take them home 'cause they're tired of getting squirted lol) so each day we try to do something different.

We're not setting it up as a competition style event, since that mandates a winner and loser. Boys in this age range still get very emotional over these things, tears and all. We want all of them to have fun, even the kid that couldn't hit the broad side of a barn. We'll probably setup targets for them to shoot at and let their imaginations take over. Also we are not allowed to design an activity that says go fire at each other - some kids don't like to get squirted, but of course boys will be boys and in the end, they'll all end up cooling each other off, whether from splatter/over spray or just silliness. (they always end up squirting each other anyway, we just can't tell them to)

Thanks for all of the advice and suggestions ya'll! Keep it coming!

Andrea

[HBWW]

Not 100% sure on the check valves, but they look okay. I'm pretty sure you can't have only one check valve though, because otherwise the pump will probably draw air instead of water. A pump needs to be able to draw and push and having only one check valve won't allow this process to happen.

However, if you can get to two check valves, it's also worth looking for a small ball valve so you can create a pressurized blaster, which will generally give substantially better performance than traditional pistol pumpers. (Depending on how its designed, you should be able to surpass the performance of the syringes as well.) What you can do is build a pump that pumps in air (unless you can find a bike pump and Schradder valve for cheap, as that's an easier option) and have the bottle filled up before it's pumped up for a traditional pressurized reservoir blaster. It'll take some research to find something that works, but it's worth it IMO if you're going to go with having check valves on the design.

[marauder]

If you are worried about the weight, you may want to go with 1L bottles instead. That will still give kids a lot of shots per tank, and it would save you money.

[atvan]

Check valves that tiny will be hard to pull/push water through- it's like breathing through a coffee stirrer.