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What do you want to know?

Posted: Sat Mar 08, 2008 4:09 pm
by SSCBen
Is there anything specific you want to know or want us to write about water gun physics? Some sort of Q&A thread would help people understand what's going on.

Right now I'm trying to figure out the relationship between LRT pressure and the two variables that control it, wall thickness and inner diameter. This would give us a better idea how stacked tubes or thicker tubes that may be available in the future would work.

After that I want to finish checking my Bernoulli equation derivations to see if they are correct, and then make a spreadsheet similar to the APH tool to work with them.

Re: What do you want to know?

Posted: Tue Jun 17, 2008 2:48 am
by used man
How would you make the pump for a pressurized resivoir gun??

Re: What do you want to know?

Posted: Tue Jun 17, 2008 12:51 pm
by SSCBen
The pump would be exactly the same as a normal pump. This time you're pumping air so one check valve will lead to open air. Simple.

Alternatively you can use a bike pump. The best thing you could do would be using a schrader valve that attaches to a bike pump. Some of them you can fit directly into PVC fittings and you can PVC cement them on. It won't be the best seal (I've done this before and they've come out eventually) but it'll be decent.

Re: What do you want to know?

Posted: Tue Jun 17, 2008 2:36 pm
by Silence
You can also vary the design slightly so that the inlet check valve becomes part of the pump rod. That's how bike pumps work. Scavenger dismantled and took pictures of a Schwinn Air Driver 700. Of course, it is a bit of a hassle, but it's easier than making a check valve and it's cheaper than buying one.

Is there any particular reason you're interested in pressurized reservoir? They perform well enough, even if there's dead space between the check valves*, but you can't fill it up without losing all the pressure. They're practical for pistols, though.