Modification to piston gun

Build a homemade water gun or water balloon launcher and tell us about it.
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soaked
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Joined: Sat Dec 09, 2006 5:28 am

Modification to piston gun

Post by soaked » Sat Dec 09, 2006 5:37 am

YAY! my project is finished. Its a standard piston gun with a simple modification; you barely ever have to reload! I made a hole at the front of my pistol on top and attatched a lid from a coke bottle. Using a simple flap valve it opens, letting more water in when you draw the piston back, and when you push the piston forwards the valve shuts, and it fires like a normal gun.

Ill get some photos and diagrams up soon.

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

Post by Silence » Sat Dec 09, 2006 10:32 pm

Nice, I'm waiting to see the pictures! So is it just a check valve/one-way valve?

Is the coke bottle the reservoir?

soaked
Posts: 4
Joined: Sat Dec 09, 2006 5:28 am

Post by soaked » Sun Dec 10, 2006 2:36 am

I made a newer model today with a few improvements.
From the first to the second model i have found that: the water needs a fairly small hole to exit the gun through. A valve is not required, and it only adds more complexity, A near perfect seal is required on the piston.

It is basically a small piston gun, but just think of a bottle cap with a hole going through it into the pvc. Then just screw a bottle filled with water on top, and you won't be running out of ammo any time soon.

The bad news: it's not perfect. I can't get a perfect seal around the piston, and range is only about ten metres, but fortunately whatever it hits, it drenches.

Once i get the batts charged for my kodak ill get some shots.

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

Post by Silence » Sun Dec 10, 2006 5:35 pm

Generally speaking, these are the measurements we use for pumps:
- 1/2" PVC for the pump tube (the ID/inner diameter is actually a bit larger than 1/2")
- 3/8" OD/outer diameter for the pump rod
- O-ring with 3/8" ID and 5/8" OD
- Electrical tape wrapped around the pump rod on either side of the O-ring to keep it in place

What is the diameter of your pump tube? It should be a bit larger, maybe 1" for best performance, and I can give a few size suggestions once I know the size of the tube. Thanks.

soaked
Posts: 4
Joined: Sat Dec 09, 2006 5:28 am

Post by soaked » Mon Dec 11, 2006 6:26 am

the pvc would be about 1/2 inch but i couldnt find the right size inner pipe. so i just had to use a larger o ring. not working to well, as the o ring flexes

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