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I need help with my APH design

Posted: Tue May 10, 2011 11:02 am
by Ratzul
Hello, I have been looking around at the forum for a while and decided to make an APH myself :)

This is (almost) what i want to make:

Image

The handle connects to a back pack with water, and the PC itself is supposed to be inside the big T.

I might want to make a gun that realeases all the air at once and pumps as litlle as possible (This would not be a watergun)

Also I have a feew questions:

What size should all the pipes exept the big T be?

What kind of PC should i use? Pressurized Reservoir | Separate Air Chamber | Constant Pressure System. I want one of these, what are the pros and cons?

Does the volume of the pump compared to the PC matter? ... for example what happens if the PC is a lot bigger or smaler than the pump?

How do i make the pump completely air/watertight? Does anyone have anny ideas or maybe a website with a good tutorial?

Re: I need help with my APH design

Posted: Tue May 10, 2011 11:08 am
by cantab
This design is not going to work properly as a water gun. Air floats on water, so in the pressure chamber of an APH, the outflow leading to the firing valve and nozzle has to be at the lowest point.

Re: I need help with my APH design

Posted: Tue May 10, 2011 12:14 pm
by Ratzul
I already tought of that... i just wasnt sure :p

What if the pc looked something like this:

Image

Re: I need help with my APH design

Posted: Tue May 10, 2011 5:22 pm
by cantab
Assuming that the tees nearest to the front are just for strength and will be blocked to water, yes that works. You don't however need a "barrel" in a water blaster; it's best to put the nozzle just forward of the forward tees. If you want a barrel to fire nerf darts or similar, I'd suggest making that attach in the same way that a water nozzle would.

Re: I need help with my APH design

Posted: Tue May 10, 2011 6:22 pm
by Ratzul
Yea, the tees are for strength. But what about my other questions :p

Re: I need help with my APH design

Posted: Tue May 10, 2011 8:22 pm
by C-A_99
PR: Mostly for cheap, compact blasters that are still somewhat powerful.

Separate air: Gives more flexibility to power level than CPS, in that you can choose to pump more or less air when using. Pre-pumping always a must to achieve optimum performance, and if your pump seal is less than perfect, it will not work out.

CPS: Easier to use and work with, though you do have to mind the bladder and build a protective casing for it. Ruptured bladders are a big problem with homemades. You can use LRT to do this, or you can use party balloons. Power is generally controlled by stacking more or less bladder layers over each other.

Re: I need help with my APH design

Posted: Wed May 11, 2011 7:38 am
by Ratzul
Ok, I think i want to make one with a separate air champer. Also if I have a long barel but I put my firing valve at the end like this:

Image

Would it improve my performance? (for a water gun)

Edit: Ok I realise im asking a bit much :p but i kinda tought thats what this forum is for, and i really want to do this right. The only question I cant find answered in the forum is What size sould the pump be compared to the pc?

Re: I need help with my APH design

Posted: Sat May 14, 2011 8:18 pm
by zeda.beta
The pump is dependant on two things: How much water you can pump comfortably, and how big the rest of the gun is. If you can't pump the gun, you can't fire it, and if it is a larger size than the rest of the pipe, you have to use a ton of reducers (Pain in the ass BTW never do that)

Oh yea, and I'm not quite sure if your performance would improve, but it couldnt hurt to have the valve as close to the nozzle as possible.