Super Soaker Central

I just finished my homemade yesterday, and I'm testing it today.

It's based on the APH, but the pump is on the backpack.

Later on I'll post about it's range and other things.

I will write a guide if you want me to.

P.S. How do you post a picture on this forum if it doesn't have a URL?

Read our guide on posting images; it tells exactly what you got to do.

I don't think anyone has put the pump in the backpack. It's possible. I'm interesting in seeing pictures of the gun.

Note: If a larger view of the picture is desired, click on it.
Here is the gun.
The backpack has to be treated as a sling in order to use the pump.
The gun has 1PC, which is a 90 degree 5" 3/4" piece of PVC pipe.
This is the main nozzle it uses, sized at 5/64". Extras I added are a black strap, flashlight, and the water carrier's sticker.
Two shots from the gun off a deck.
Range: roughly 50 feet
Nozzle Size: 5/64"
Shot Time: Not measured, but around a minute or so.
Range: Roughly 25 feet
Nozzle Size: 1/4"
Shot Time: Not measured, but around 5 seconds.

Range: Roughly 5 feet
Nozzle Size: Riot Blast (3/4" PVC)
Shot Time: About 1 second.
(Sorry I didn't get a picture, but it was extremely weak anyway)

A problem I encountered was a minor leak in the pressure chamber, which can be fixed with PVC Solvent.

The riot blast and larger nozzle were weaker because of the gun's tiny pressure chamber.

Thoughts, Questions, Comments, Creative Criticism, or Anything are welcome.

What should I name it?

I guess it's an APH prototype.
Here's a picture of it hitting my little brother's tree house.

This is a bit unusual. The reservoir looks like a garden sprayer. But they normally work by pumping air, pressurising the reservoir. I have one, its water gun performance is limited by constriction in the valve.

I did that because I wanted to get a 2 gallon container.

I modifidied this because before I had 2 pumps, and it needed 2 be shot by 2 people.

I'm confused about the gun's pressure chamber. Is it really just an angled 5" 3/4" PVC section? If it is, I doubt the gun works, but the pictures show otherwise.

To me, 50 feet stretches what I thought a gun like this could do, though I see you are shooting off a deck and down a hill from the pictures, and shooting off a raised platform and down a hill increase range many times. Try shooting the gun on level ground and measuring it for us; for more information, see our article on this. We use these standards to easily compare our guns and to avoid errors in measurement.

I've been indirect up to this point, but now I'll say what my problem is. Air rises; water falls. This principle works inside a gun's pressure chamber, and drives how air pressure water guns work. The key to this principle is to keep the air at the top of a pressure chamber, never at the bottom. Air at the bottom won't power the gun and will keep it from working. Remember: Air on top, never on bottom.

Some diagrams should show this principle and how much it matters when designing an air pressure water gun.



This image shows a normal, APH-style pressure chamber. The chamber is perpendicular to the pipe below it. The first image shows the water level and air flow direction when the gun is level; the second shows the water level and air flow direction when the gun is angled up to get the best range. Here, the water level changes and remains flat to the ground but angled within the pressure chamber. This angle can create problems if the builder ignores it.



Here is the case, which unfortunately is the same case as in your gun. The water level actually pushes some water into the pressure chamber, not out of it. When it does it, the gun shoots air and not water, because the air is closer to the nozzle. The air has to be on top to push the water out; if the air's on the bottom, it just escapes out and the water stays put. Granted, depending on the pipe size and other factors, guns like this can shoot some water, but not all the water in the chamber.



Not all angled pressure chambers keep the gun from working. If the builder angles the chamber towards the nozzle, like in the diagram I put above, it actually creates a situation where the gun shoots much better when angled, but poorly when shot flatly.

Do you see my problem now? I can't see how the gun works, because it should be shooting air and not water.

Does your gun shoot air for part of the shot? If it does, you should rebuild it from scratch, because it will always perform poorly. If not, I guess you were lucky.

One problem with the article on measuring ranges: there is no standard for nozzle position and height from the starting point of the range. This point is necessary to prevent inconsistencies in shooters' height and arm's reach.

Aside from the problems Drenchenator mentioned, that pressure chamber is way, way too small to be able to do anything. One piece of advice when building homemades: do NOT add extra nor manipulate the design in order to accomodate for ergonomics. I noticed that you tried to shape the PC like a convinient handle, which not only causes the problems mentioned, it is far too small. Another thing you want to avoid is adding handles that are part of the water system; this creates a lot of dead space with water that has to be emptied out. From your pictures, you added the handles externally instead, which is good practice. (though those handles appear to be somewhat weak)

There are a few exceptions to that. One of them is DX's N-rev designs of 2006. They don't seem to have taken off, but he did build a design where a 3" PC curved in the direction Drenchenator mentioned (it curved gently about 25°-45°, not with a 90° bend) and that PC also served as a handle.

Fix up your design. Give plenty of space for the pressure, cut off and rebuild whatever you have to, and you'll get very impressive results. I also recommend that the pump is on the gun instead of the backpack. (there are a few exceptions; sometimes pumps can be attached to backpacks if the design doesn't demand any pumping during shooting)

Thanks for the advice.

I will modify it, but can't yet due to a lack of funds.

Drench, if the water gun is held at a straight angle, it looks like the diagram at the left.

I guess I got lucky, because the gun takes the air to shoot the water further, it's like little bursts at the end of the shot.

The pump in the backpack pushes the water down the tubing at high speed, and that produces a longer shot time.

Sorry I shot off a deck, the reason was because of my broken leg, which would make it hard 2 properly measure, but maybe in 2 weeks I could measure it better.

I think I'll build another gun, and use your advice

I got a bit confused on how this gun operates. I'm assuming now that the pump on the backpack pumps air into it, while the handle serves as an extra channel of air to push the water more. What I'd do instead is to have an LPD kind of layout in the backpack, leaving lots of room for air which is to be pre-pressurized. Then, all the "gun" has to be is a ball valve attached to a hose. Keeps everything nice and simple and the whole gun is pumpless.

Drench, if the water gun is held at a straight angle, it looks like the diagram at the left.

Perhaps I should have specified more: to get the highest range, you need to angle the shot, so with your gun you never get the highest range because it can't shoot at an angle. Other than that, it should still shoot, just not in all situations.

Sorry I shot off a deck, the reason was because of my broken leg, which would make it hard 2 properly measure, but maybe in 2 weeks I could measure it better.

There's no harm in waiting, especially if you are hurt. I hope you get better soon.

Welcome to the forums JuchTurtles. That's a creative-looking color scheme, and I like the shape of the handles on the water gun body?

You say there's a pump in the backpack, but I'm a little confused as to where it is. Could you explain further? Thanks.

@Silence: the backpack is a garden sprayer. Btw, im building another homemade, and the pump is on the gun. Details coming soon.