APH customizations

Build a homemade water gun or water balloon launcher and tell us about it.
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djohnson293
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APH customizations

Post by djohnson293 » Wed Jun 25, 2008 9:05 pm

As a person new to building water guns, I want to build an APH to get some experience before I go on to other things. I was looking at the page on APH customizations and the supercharged or pre-charged customizations caught my attention. I couldn't get any more information on these. Can you guys give me any information about those mods or other cool customizations?

aEx155
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Re: APH customizations

Post by aEx155 » Wed Jun 25, 2008 9:17 pm

I believe that "charging" and APH has to do with finding a way to pressurize the PCs with extra air, additional to the air in there already and then adding water.This typically includes using a piston in the PCs; air is pumped in on one side of the pistons, and the water is pumped in on the other,

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Drenchenator
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Re: APH customizations

Post by Drenchenator » Wed Jun 25, 2008 9:35 pm

aEx155 is right. A "supercharged" or "precharged" gun is just one in which you put some extra air pressure. Pumping can't get very high pressures without requiring a lot of force, so adding extra air is an easy way to--for one shot only--boost the pressure and performance.

In my opinion, this is extra work without much extra benefit. The beauty of the APH is that you just pump it and shoot it like any normal stock gun--no compressor or air pump required. If you just want experience for future ones, first build a fairly standard APH and later move onto these more complicated designs.
The Drenchenator, also known as Lt. Col. Drench.

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SSCBen
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Re: APH customizations

Post by SSCBen » Wed Jun 25, 2008 10:15 pm

That's one part of the guide I never finished and forgot about. Thanks for the reminder.

You can attach a simple schrader valve to your water gun to get a pre-charge ability. Of course, that alone isn't ideal because when the shot is done your extra air will leave through the nozzle unless you're very good about closing it before it escapes. Follow the thread tapping procedure in RolandTower's water gun to attach the scrader valve. Piston cups can be bought from McMaster-Carr. Follow the procedure for Supercannon II to install the piston. Then you have a pre-charged water gun.

The Supercharge ability makes it work like Supercharger Super Soakers. You could attach it to your hose to pressurize it. That's all. You actually can do that with the standard APH design if you use a hose coupler as a nozzle. Attach the APH to the hose, turn on the hose, pressurize completely, close the ball valve, turn off the hose, remove the hose coupler, attach your nozzle and you've supercharged your water gun. That's not the best way to do it obviously. A built in hose coupler would be ideal.

Most of the customizations people haven't done or haven't done often so there's not always much to talk about. I had hoped that people would submit some interesting things, so if you do try anything neat let us know.

Now that I think about it I might make a precharger water gun to get rid of some extra parts. That would be an interesting project.

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djohnson293
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Re: APH customizations

Post by djohnson293 » Wed Jun 25, 2008 10:49 pm

Thanks for clearing that up for me. What are the range/power benefits of precharging/supercharging?

aEx155
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Re: APH customizations

Post by aEx155 » Wed Jun 25, 2008 11:02 pm

The only benefit would be increased pressure for the one shot you use it for; that's about the only advantage I see...

You probably wouldn't be able to pump it after you use the water up, so you would have to go empty the air, fill, and charge again for each shot; that takes time, and isn't very simple to do...

As for range, it depends on how you make your gun, like always. If you find a was to use that extra pressure efficiently, then it should work out well. Power would be higher, of course, since you're adding more energy to the water gun.

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cantab
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Re: APH customizations

Post by cantab » Wed Jun 25, 2008 11:10 pm

Related - can the APH be primed/precharged in the same way as stock seperate firing chamber guns can, ie using the normal pump to pump extra air into the PCs before filling them with water.

aEx155
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Re: APH customizations

Post by aEx155 » Wed Jun 25, 2008 11:31 pm

cantab wrote:Related - can the APH be primed/precharged in the same way as stock seperate firing chamber guns can, ie using the normal pump to pump extra air into the PCs before filling them with water.
It is true that APHs can be primed in that fashion, but it might be harder since most APHs don't have an on board reservoir. For normal guns, you can prime it before you add water, but it's easier to conserve that air because of the trigger; also, when you accidentally exhaust that air, you can (sometimes) turn the gun upside down to re-prime it without having to disconnect/empty anything.

With an APH, it becomes much harder...ball valves don't close instantly, making it harder to conserve the air, and since most APHs use backpack reserviors, there is no way to "turn the gun upside down" (put it in a state where you pump air, not water) unless you empty the gun

That's where pistons and air pumps come in; the pistons prevent the air from exiting when you exhaust all your water, while the pumps let you do it when your gun has water in it. You could do it without pistons, but then the same problems would arise. You could also do without pumps, but you would have to be careful on how you fire to conserve air.
Ben wrote:Now that I think about it I might make a precharger water gun to get rid of some extra parts. That would be an interesting project.
That reminds me; that's exactly how my homemade works (in a certain configuration); the hose connection allows you to fill it up with a hose (or with the attachable pump). I actually did that once using some quick-disconnects and it worked really well.

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Silence
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Re: APH customizations

Post by Silence » Wed Jun 25, 2008 11:40 pm

There are a few different types of pumping in air pressure water guns:
  • separate chamber precharging - pump air first, then water
  • separate chamber regular - pump water
  • postcharging / supercharging / pressurized reservoir - fill with water, then pump air
In the end you still have to get to the same pressure.

For most applications, separate chamber regular is best because when you're pumping water, you don't have to worry about dead space - areas where the pump fluid compresses but doesn't enter the pressure chamber.

Precharged separate chamber is used in the Water Warriors Argon, Xenon, and Krypton. Because you pump in air that is never released until you stop using the soaker, the pressure never drops below a certain level (determined by what you precharged it to). That results in more constant pressure than you could get with a regular air pressure water gun.

Pressurized reservoir has a few applications.
  • In small water pistols, there may not be enough space to have multiple chambers. Because you can just pour in the water, the same tank functions as both pressure chamber and reservoir.
  • In some cases (read: Supercannon II), the pressure chamber is so large or the pressure is so high that it's more convenient to use an automatic pump or a foot pump instead of a regular hand pump. These water cannons are optimized for high flow, with a massive inline pressure chamber with a plunger. They're filled and shot through the same valve/nozzle.
Pressurized reservoir soakers can't be topped up with more water if you've used up half your supply. When you open the reservoir, you're also opening the pressure chamber, so you lose all the air you pumped in. Also, homemade (and some PR water gun) pumps may be inefficient thanks to dead space between the end of the pushed-in pump and the check valve - compressed air sits in there instead of passing through, expanding and contracting as you pump.

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C-A_99
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Re: APH customizations

Post by C-A_99 » Thu Jun 26, 2008 12:44 am

Hmm, after going through this thread, I'm also thinking of building an APH/Supercannon combo. It can be supercharged to high pressures and used as a single-shotter, then after the big shot, I can press on the shrader valve, which releases excess air to ease pumping,, then proceed to pump water from a regular hand pump. However, I'll also need a backpack since the design will be pretty large and water-demanding.

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djohnson293
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Re: APH customizations

Post by djohnson293 » Thu Jun 26, 2008 12:49 am

One last question about APH customizations. If I make a 4 chamber APH, can I place an extra ball valve after the second PC to make a two-shot APH?

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SSCBen
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Re: APH customizations

Post by SSCBen » Thu Jun 26, 2008 1:00 am

No, that wouldn't work as you expect it would. If you close the ball valve and then shoot, your first two PCs will have equalized with the outside environment, having a pressure difference of 0 PSI. Let's say your second set of PCs has a pressure difference of 80 PSI. After closing the shooting valve and opening the ball valve, the pressure in all chambers will equalize to 40 PSI. So your pressure would be cut in half on the second shot.

In my mind there's no reason to design like that. The only way for that system to work satisfactorily would be to have valves for every chamber so you can switch some on and off. It adds cost and complexity. Operating the valves would be slow. Having one long shot is the most straightforward option.

With that being said, if you really wanted this feature, try it out. All you'd need to do is add one valve per PC (or one valve for a group of PCs, but the group has to all connect to that valve and that gets bulky). If it works for you, great.

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C-A_99
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Re: APH customizations

Post by C-A_99 » Thu Jun 26, 2008 1:21 am

Here's a PVC diagram of what I was talking about in my earlier post.

Image

Pump and 2nd check valve placement need to be looked at for best efficiency. Still, this gives a general idea of a pre-charger APH with both Supercannon and regular APH capabilities.

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Drenchenator
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Re: APH customizations

Post by Drenchenator » Thu Jun 26, 2008 2:24 am

Interesting idea. It's really just a Supercannon II with a water pump, but still, it's a good idea. I know one of the big things that makes Supercannon II very unpractical is the time it takes to reload. This might make it easier, though it makes the gun larger, though the gun doesn't really have to be Supercannon II size--it can be much smaller if needed.

The diagram should have an air release valve on the pressurized-air side. Other than that it describes the concept perfectly. Good idea!
The Drenchenator, also known as Lt. Col. Drench.

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C-A_99
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Re: APH customizations

Post by C-A_99 » Thu Jun 26, 2008 2:53 am

I figured the air could be manually released by pushing on the schrader valve. How does an air release valve work? Or is it just simply a ball valve?

Right now, its at 2ft for the PC, which really isn't that large compared to some soakers. After that's the ball valve and nozzle. Unfortunately, without a rotating nozzle selector, switching nozzles after taking the big shot will be a bit cumbersome.

After reading up on Ben's reply to the other thread (getting afraid that I'm starting a parallel discussion here), he makes note that the air side can be bent in a different shape to avoid lengthening. However, this would also be restrictive on the movement of the piston (and the water volume to air volume ratio), so I'll probably stick to the original design unless in situations where a large volume of air is needed.

This is getting interesting, wonder why the idea of a supercannon with a water pump wasn't really around since it provides many more options than the standard APH.

Tactically, it'd be operated almost like a one-time Flash Flood, then switching to the smaller nozzle and releasing excess air until the user can find time to supercharge again. Obviously, this is on a much, much larger scale than the FF and works at long range. (though if you use a short range nozzle or no nozzle, it would drench very quickly) However, I've never worked with a supercannon before and there may be better ways to go about this.

Edit: Some more possibilities including an all in one that features a WBL connected to the back of the pressure chamber. However, this makes the overall design too large for a handheld, hand-pressurized water gun.

I should probably have put an onboard air pump at the back of the PC on my diagram but I thought I shouldn't have until I've verified that onboard air pumps can work reasonably well, which I'll be able to verify once my direct-fire WBL designed for sniping is completed. I don't know if onboard air hand pumps can get up to 60-80 PSI, which is the standard for both WBL's and, I believe, for supercannons as well.
Last edited by C-A_99 on Thu Jun 26, 2008 3:35 am, edited 1 time in total.

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