school assignment

Build a homemade water gun or water balloon launcher and tell us about it.
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used man
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school assignment

Post by used man » Wed May 07, 2008 2:30 am

i made a bet with my science teacher that i could build a water gun that shoots 60 feet, know any way to get that range for a decent price?

aEx155
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Re: school assignment

Post by aEx155 » Wed May 07, 2008 2:49 am

What kind of bet? Chances are, you're going to win, so hopefully, it's not too big of a bet...

What are you planning to do as for building the whole thing? You can take a look ate the "Homemades" section for some ideas, or if you already have an idea, then you can develop it further to make is feasible.

If you want to go for cheap, you can check out my homemade, it on;y cost me $20. The only other things not included in the price were the bottles and a bike pump connection, plus the stuff to make the gun itself, but if you have those (most people do) then it should be pretty easy. I can help if you want to do that.

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used man
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Re: school assignment

Post by used man » Wed May 07, 2008 3:49 am

ya ive thouroly checked the homemades and but it has to shoot 60 ft and whether it is nerf or super soaker ive gotten lower ranges whenever modding or building so i was tryingto get something decently above

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Drenchenator
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Re: school assignment

Post by Drenchenator » Wed May 07, 2008 4:22 am

Getting 60 feet of range is doable but is no small task. How much money are you willing to put up for the project?

If by "decent price" you mean around 60 to 80 USD, you can build a SuperCPS or a similar clone like Killer 7's. It is able to top out at slightly over 60 feet at an optimized nozzle size.

You could also just build a very large pressure vessel out of PVC pipe, fill it with water, and pressurize it to as high of a pressure as you can. I think this kind of setup could get over 60 feet at about 150 psig or so with an optimal nozzle, but no one has ever built anything that stupidly simple before. Brute force doesn't always work, but a simple gun like this could perform well while keeping costs very low.
The Drenchenator, also known as Lt. Col. Drench.

aEx155
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Re: school assignment

Post by aEx155 » Wed May 07, 2008 2:07 pm

The one thing I've found is that PVC, in large amounts, is expensive, especially if you're going for a one-time use kind thing. That's why I only used 1/2" in my homemade and I used plastic bottles for the pressure chambers.

What kind of shot time do you have to have? Does it have to be long, or can you just make something that lasts a few minutes to get to 60'? If it doesn't have to be too long, then that will cut the cost, as you would use a smaller pressure chamber.

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Drenchenator
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Re: school assignment

Post by Drenchenator » Wed May 07, 2008 3:33 pm

The one thing I've found is that PVC, in large amounts, is expensive, especially if you're going for a one-time use kind thing. That's why I only used 1/2" in my homemade and I used plastic bottles for the pressure chambers.
That's not completely true. When I go down to my local Lowes or Home Depot, I can actually buy 10 foot lengths of pipe for only slightly more than a single 5 foot length. Why you may ask? It's just a bulk discount. And when compared to other kinds of pressure vessels and pipings, PVC pipe is very cheap and gets top-of-the-line results.

Your homemade may have used 2L bottles for the pressure chambers, but it performed up to par for what it was made of. If you want a high performing homemade--say, one that shoots 60 feet or so--you have to at least buy something for the chamber that can take some pressure. 3" schedule 40 PVC is just that. Plus, it's available locally and for cheaper than anything else of its kind.
The Drenchenator, also known as Lt. Col. Drench.

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Silence
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Re: school assignment

Post by Silence » Wed May 07, 2008 9:55 pm

PVC of large diameters is certainly rather expensive. The relation between price and diameter is probably a quadratic fit, if not more. 2L bottles should perform just as well at any given pressure, but only until they burst...

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used man
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Re: school assignment

Post by used man » Wed May 07, 2008 11:09 pm

well the bet has been modded, it only has to shoot 50 ft. and i have a broken aph that i am going to fix and improve. i will call it the aqualord h-n-r (yes the name is a joke) hnr stands for hit and run. because if you look at bens aph you can see there is a screw off part in front of the second check valve. switch the spot of check#2 and the screw piece. pump it from a pool ant then you have an extremely compact aph. i was also gonna make the pc's tiny.

aEx155
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Re: school assignment

Post by aEx155 » Thu May 08, 2008 4:12 am

Whoops! I didn't realize what I said. What I meant was what SilentGuy said. At my Home Depot, the sewer drain pipe they had was so much...and it wasn't even pressure rated. Would the pressure rating make a difference in price?

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SSCBen
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Re: school assignment

Post by SSCBen » Thu May 08, 2008 2:05 pm

used man wrote:well the bet has been modded, it only has to shoot 50 ft. and i have a broken aph that i am going to fix and improve. i will call it the aqualord h-n-r (yes the name is a joke) hnr stands for hit and run. because if you look at bens aph you can see there is a screw off part in front of the second check valve. switch the spot of check#2 and the screw piece. pump it from a pool ant then you have an extremely compact aph. i was also gonna make the pc's tiny.
An APH should get 50 feet angled easily. Try different nozzle sizes until you get one that works best.

Making the PCs tiny would decrease range in my experience though. I wouldn't suggest anything smaller than 500 mL of water or so. A single chamber APH with 3 inch chambers made as small as it can be would get at least 600 mL of PC, so I would suggest that if you want something small. Otherwise you will have to use 2 inch pipe.
aEx155 wrote:Whoops! I didn't realize what I said. What I meant was what SilentGuy said. At my Home Depot, the sewer drain pipe they had was so much...and it wasn't even pressure rated. Would the pressure rating make a difference in price?
The pressure rating would make a big difference in price. Pressure rated pipes are typically more dense and consequently weigh more. They use more plastic and will cost more. Sewer drain pipe should be pretty cheap. I recall that a 10 foot long piece costs a fraction of 4 inch PVC pipe (non-pressure rated) and weighs a fraction of the weight as well.

aEx155
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Re: school assignment

Post by aEx155 » Thu May 08, 2008 10:00 pm

The pressure rating would make a big difference in price. Pressure rated pipes are typically more dense and consequently weigh more. They use more plastic and will cost more. Sewer drain pipe should be pretty cheap. I recall that a 10 foot long piece costs a fraction of 4 inch PVC pipe (non-pressure rated) and weighs a fraction of the weight as well.
Well, a 2' section of 4" sewer drain pipe cost around $3-$4 at the Home Depot I went to...so I don't know...

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SSCBen
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Re: school assignment

Post by SSCBen » Thu May 08, 2008 10:57 pm

That's weird. A 10 foot piece costs $7.35 at the Lowes nearest where I live according to their website. I couldn't find the same pipe at Home Depot, so it might not be listed on their website. Maybe you're looking at the wrong stuff. Drain pipe usually has a belled end and is pretty thin. Those prices sound more like non-rated PVC pipe.

aEx155
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Re: school assignment

Post by aEx155 » Thu May 08, 2008 11:47 pm

Ben wrote:That's weird. A 10 foot piece costs $7.35 at the Lowes nearest where I live according to their website. I couldn't find the same pipe at Home Depot, so it might not be listed on their website. Maybe you're looking at the wrong stuff. Drain pipe usually has a belled end and is pretty thin. Those prices sound more like non-rated PVC pipe.
You're right. The stuff was black, and had a bunch of bubbles in it. I believe it was cellular core pipe, which I know isn't pressure rated...but I may be calling it the wrong thing; I know it is used for drains, but I'm not sure of the exact name.

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Drenchenator
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Re: school assignment

Post by Drenchenator » Fri May 09, 2008 12:09 am

If it has bubbles in it, it's cellular-core pipe. If it's very thin--less than an 1/8 of an inch, I believe--it's drain pipe. Cellular-core is just as rigid as schedule 40 pipe; in fact, it looks pretty much the same if you don't count the bubbles. Drain pipe is decently rigid, but nowhere near as rigid as schedule 40 pipe.
The Drenchenator, also known as Lt. Col. Drench.

aEx155
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Re: school assignment

Post by aEx155 » Wed May 14, 2008 2:28 am

I wonder if he won the bet...

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