Page 1 of 1
Adding pumps on water pistols?
Posted: Tue Jul 01, 2008 4:08 am
by Negative
Anyways, I was trying to make an insanely powerful water pistol (For kicks). I bought one some time ago, and it's small, about the size of the palm of your hand. After widening the nozzle, next step is the pump. Can anyone explain how a pump works, or tell me how to build/attach one, and create a pressure chamber?
Edit:
After closely examining the inside of the pistol, I have realized that a pump would be impossible. But, for further reference, I would still like to know about pumps. 
Re: Pumps on water pistols?
Posted: Tue Jul 01, 2008 12:11 pm
by Silence
Welcome aboard, Negative!
This HowStuffWorks page on the Super Soaker details the flow of water through a water gun. Here's a brief list of parts:
- first check valve - a valve that allows water to flow only from the reservoir/tank to the pump
- pump - increases and decreases in volume as you pump
- second check valve - a valve that allows water to flow only from the pump to the pressure chambers
- When you extend the pump, water has to enter by coming from the reservoir. When you contract the pump, it has to leave by entering the pressure chambers.
Our homemade water guns section has primers on building pumps (scroll down to the third table) and an air pressure homemade walkthrough.
Re: Pumps on water pistols?
Posted: Tue Jul 01, 2008 12:23 pm
by cantab
So basically, are you trying to make a really small gun with good power? If so, then I'll say that while that's possible, there will be drawbacks. Generally higher ranges require higher outputs, which means you'll get through your water more quickly. Sure, you might be able to shoot 40 feet, but you might only get two such shots.
I'm assuming what you've got is just a cheap squirt gun. The body of that won't hold pressure, so you'd be better off building your ultra-small water gun from scratch.
Also, unless you're going to connect it to an external reservoir (eg a backpack), I'd suggest using a pressurised reservoir design. You won't get insane performance, but I'm should you could outrange the XP215.
What to use for the trigger is an interesting question. Normally homemades use ball valves, but they make tap shots impossible. Other valve types can open and close much more quickly, but will make the flow turbulent and possibly restrict it, which will reduce power.
Re: Pumps on water pistols?
Posted: Tue Jul 01, 2008 5:08 pm
by Drenchenator
Welcome to SSC!
If you use a pressurized reservoir design, all of the mechanism to power the gun can be removed. I'm thinking of a gun that is just an input valve for air, an input valve for water, a chamber, and a firing valve (ball valve for space) and nozzle. That's it; it's really that simple at that point. Depending on the pressures involved, it should have at least decent performance if not excellent.