My P.R.H.

Build a homemade water gun or water balloon launcher and tell us about it.
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martianshark
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My P.R.H.

Post by martianshark » Fri Jul 17, 2009 5:06 am

This is a pressurized reservoir water gun that I made out of a 2 liter soda bottle and some PVC pipe. Here are some facts about it:

Range: 46 ft
Capacity: about 2 qts
Shot time: about 5 secs

I might post the instructions to making it later.
I also plan on making a better version.
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cantab
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Re: My P.R.H.

Post by cantab » Fri Jul 17, 2009 1:30 pm

Looks simple and effective. Is that a sock covering the bottle? Should help safety.
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
Water Warriors: Jet, Sting Ray M, Shark, Argon M, Tiger Shark, PulseMaster
Others: Waterbolt, The Blaster, Storm 500, Shield Blaster 2000, generic PR gun, generic backpack piston pumper (broken), 3l garden sprayer M, 10l water carrier:

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martianshark
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Re: My P.R.H.

Post by martianshark » Fri Jul 17, 2009 10:05 pm

Yes. I put a soccer sock over the bottle to prevent it from blowing up in your face. By the way, I finished the better version of this water gun, but I don't have any pictures yet. It's range is 49 ft instead of 46. It's shot time seems to be longer too.

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C-A_99
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Re: My P.R.H.

Post by C-A_99 » Fri Jul 17, 2009 11:19 pm

The bottle is more likely to shoot off it's threads than to blow up, and a sock isn't going to stop that if it happens. If you're using a bottle designed for soda however, it should be fine anyway since those bottles are generally designed to hold a lot of pressure.

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martianshark
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Re: My P.R.H.

Post by martianshark » Sat Jul 18, 2009 2:49 am

I now have pictures of the better version of my water gun. I also found out that the range is 9 seconds! :D
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Silence
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Re: My P.R.H.

Post by Silence » Sat Jul 18, 2009 4:53 am

Looks cool – is it modeled after Ben's 2 liter homemade?

I'm interested in seeing the quick-fill attachments you use. I see there are two different ports used when filling, but what's are the pieces that you actually screw onto the hose?

You know, that's impressive range for a water gun filled straight from the hose – it'll outrange pretty much every commercial water gun you'll find. Does it beat your hose's range?

And my final question, what size drill bit did you use for the nozzle? It sounds like a good combination for range and shot time.

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cantab
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Re: My P.R.H.

Post by cantab » Sat Jul 18, 2009 12:15 pm

I presume the wide opening with the ball valve fills water, and then the schrader valve allows pressurising with air.

Does look good.

Thinking about it, pressurised reservoir has one big pro for homemades - air pumps can be easily got (bike pump basically). Making the pump seems to be the hardest aspect for seperate PC homemades (whether APH or CPH), so cutting that out could be good.
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
Water Warriors: Jet, Sting Ray M, Shark, Argon M, Tiger Shark, PulseMaster
Others: Waterbolt, The Blaster, Storm 500, Shield Blaster 2000, generic PR gun, generic backpack piston pumper (broken), 3l garden sprayer M, 10l water carrier:

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C-A_99
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Re: My P.R.H.

Post by C-A_99 » Sat Jul 18, 2009 5:17 pm

Silence, I don't think it's possible for a homemade to surpass the range of the hose it's filled from. That is, unless you're talking about the hose being used with a standard attachment designed for gardening, not water warfare. Just about any pressurized homemade can easily outrange that.

The sock just makes it look goofy IMO. If you haven't secured the threads, that will be the point most likely to break first anyways, and the sock won't stop it if it shoots off. Then again, if that happens, the user will most likely just get soaked, not hurt. I'd personally keep it off just for looks and so that it doesn't absorb water, but I highly doubt the bottle would explode anyway unless it's pumped to high pressures, at least 140 PSI. Then again, I already mentioned this in my previous post and it's up to you.

How do you plan on getting a bike pump on there? My first though from looking at it is to get one of those dinky pumps, the ones as small as XP/Max-D pumps, and duct tape it on. But even so, there's not a lot of space on there.

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martianshark
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Re: My P.R.H.

Post by martianshark » Sat Jul 18, 2009 9:39 pm

Silence wrote:Looks cool – is it modeled after Ben's 2 liter homemade?

I'm interested in seeing the quick-fill attachments you use. I see there are two different ports used when filling, but what's are the pieces that you actually screw onto the hose?

You know, that's impressive range for a water gun filled straight from the hose – it'll outrange pretty much every commercial water gun you'll find. Does it beat your hose's range?

And my final question, what size drill bit did you use for the nozzle? It sounds like a good combination for range and shot time.
My water gun doesn't work how you think it does. No, this isn't based on the 2L homemade. This is my own design. It doesn't use a quick-fill attachment. One ball valve is used for shooting, and the other is for filling by simply pouring water into it. It pressurizes by hooking up a bike pump to the tire valve that I put on it. Yes, my P.R.H.'s range beats my hose's range. Also, I did not drill a nozzle. I put on a male hose adapter, and screwed on a sweep nozzle that was meant for a garden hose.

By the way, there is another big advantage to making a P.R.- It's cheap because there are no check valves requierd! :)
Last edited by martianshark on Sat Jul 18, 2009 9:45 pm, edited 1 time in total.

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cantab
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Re: My P.R.H.

Post by cantab » Sat Jul 18, 2009 9:44 pm

C-A_99 wrote:Silence, I don't think it's possible for a homemade to surpass the range of the hose it's filled from
That's the case when pressure comes from the hose. In this case, pressure comes from an air pump, the hose is just for water.

The design could be simplified by removing the fill port, and instead unscrewing the nozzle and opening the firing valve to fill. Assuming the opening by such unscrewing is big enough. Obviously this is slower, but it's not worse that stock guns.
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
Water Warriors: Jet, Sting Ray M, Shark, Argon M, Tiger Shark, PulseMaster
Others: Waterbolt, The Blaster, Storm 500, Shield Blaster 2000, generic PR gun, generic backpack piston pumper (broken), 3l garden sprayer M, 10l water carrier:

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Silence
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Re: My P.R.H.

Post by Silence » Sat Jul 18, 2009 10:38 pm

Ah, thanks for the clarification, martianshark. Using an air pump makes it more versatile – you can fill from any water source without needing a hose. Glad to hear it wasn't too expensive, either.

C-A 99, a hose-filled water gun *can* perform better than a hose if you spend 1 minute filling, but trade shot time for output and spend half a minute firing out of a larger nozzle.

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cantab
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Re: My P.R.H.

Post by cantab » Sun Jul 19, 2009 12:22 am

Silence wrote:C-A 99, a hose-filled water gun *can* perform better than a hose if you spend 1 minute filling, but trade shot time for output and spend half a minute firing out of a larger nozzle.
I thought about this myself, and I'm not sure. A hose delivers a certain pressure. If used to fill and pressurise a water gun, the same pressure is obtained. For that pressure, there will be an optimum nozzle size. Surely this is the same whether it's on the end of the hose, or on a water gun? What am I missing here?
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
Water Warriors: Jet, Sting Ray M, Shark, Argon M, Tiger Shark, PulseMaster
Others: Waterbolt, The Blaster, Storm 500, Shield Blaster 2000, generic PR gun, generic backpack piston pumper (broken), 3l garden sprayer M, 10l water carrier:

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Silence
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Joined: Sun Apr 09, 2006 9:01 pm

Re: My P.R.H.

Post by Silence » Sun Jul 19, 2009 12:45 am

The maximum orifice size isn't dictated by the pressure; it's dictated by bottlenecks and capacity. The flow rate for a hose is limited along the way from the locality's pump to your nozzle. If you build a hose-chargeable water gun with huge tanks and bore, then it can support a large nozzle even if its pressure may not be the greatest.

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C-A_99
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Re: My P.R.H.

Post by C-A_99 » Sun Jul 19, 2009 1:20 am

Well capacity's a given, so for sake of convinience, we'll just assume that capacity is enough to sustain a shot. Next would be bore, nozzle orfice, and pressure. For a given bore size, higher pressure allows for higher orfice (so long as it's in the limits of what the bore can handle); if pressure is too low, it won't push the water out of the orfice fast enough before lamination restricts range. Also, bore size/flow rate does not matter given the nozzle orfice is small, i.e. you'll get similar performance from an XP vs. a CPS 2000 with a 2mm nozzle. A CPH will have the same capability from the same 2mm nozzle regardless if 1/2" or 3/4" pipe is behind it. This starts to change at higher pressures and larger nozzle orfices; the bore size must increase along with the flow needed, and is of course, why many WW's don't perform well on their large nozzles

So the hose would have to have a pretty small bore for that to be the restricting factor. (and thus, allow a gun charged by it to shoot farther) Most, if not all hoses are 3/4" (which goes into 3/4" brass pipe in my house), plenty to shoot well with, and I'd think pressure would be the bottleneck here that would prevent such a gun from shooting farther.

On the other hand, if you turn on the hose on without any nozzles, and instead of dumping out, the water riot blasts out, then bore is definately the limiting factor here, and a custom built gun with a larger bore would be capable of a larger nozzle than the hose would, and thus be able to have more range.

@shark: On second thought, you may want to use a check valve instead of a ball valve for charging your water gun. If extra pressure is charged into the gun via pump, and someone who doesn't know how to use the gun tries to fill from the hose before letting the extra air out, the water could back shoot into the hose and maybe cause damage if pressure builds up. A check valve will ensure that never happens.

I should build something like this sometime. Nice and simple. Not the best capacity nor performance, but easy to make and easy to maintain. I may create a pressurized backpack version of this instead so it'll be easier to carry around and still have decent capacity. (though the capacity will be pretty limited if I want to maintain reasonable dropoff to prevent having to pump so much, perhaps I should build a 2L instead of a backpack)

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martianshark
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Re: My P.R.H.

Post by martianshark » Sun Jul 19, 2009 5:04 am

I thought of using a check valve, but I used a ball valve because it's cheaper.

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