3/4" pump

Build a homemade water gun or water balloon launcher and tell us about it.
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Joined: Sun Apr 27, 2008 3:13 am

3/4" pump

Post by aEx155 » Thu Mar 19, 2009 10:32 pm

I'm thinking about reviving my Soda-Bottle backpack APH, since it hasn't been fired up in a while and I might use it during the summer. In order to get the water for my (and others) guns, we use a water fountain which drains into a bucket. My water gun needs pressurized water to fill it, so I had devised a water pump to transfer water from the bucket into the gun. Unfortunately, it kept breaking.

So now, my plan is to build a two-handed 3/4" stirrup pump, rather than the one-handed 1/2" pumps. This way, the pump shaft will be stronger, and my gun will fill faster.

Since I haven't built it yet, here is an example from scitoys.com:http://sci-toys.com/scitoys/scitoys/aero/vacuum/

I'm hoping someone can help me with these questions:

- can I still use 1/2" check valves, or will there be too much lag?
- can someone recommend some way to make it stand up?

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Joined: Sun Apr 09, 2006 9:01 pm

Re: 3/4" pump

Post by Silence » Fri Mar 20, 2009 8:12 pm

1/2" check valves will probably be fine. When pumping, most of the resistance comes from the pressure in the system, not from constricted valves.

For the stand, you could cut a hole in the top of a wooden crate. A less bulky option would be to add a tee in the bottom to prevent toppling in one direction, then use your knees to prevent toppling the other way. If that makes sense.