So I finally got some money saved and decided to build my first homemade. It's made out of 15mm PVC (about halfway between 1/2" and 3/4") and 2" PVC for the pressure chambers. Total cost was $130NZD. <_<

Putting this thing together was quite a bit more difficult and time consuming than my WBL, some of the parts were hard to glue in and I kept getting cement all over my hands! So some of the joins weren't perfect, but after anxiously waiting for it to dry I tested it. Success!

Anyway, this thing definitely has power...lots of it. However, I was a bit disappointed when the gun wasn't able to out-distance my 1000, which shoots around 40 feet. After reading other people's experiences with their homemades, I was expecting mine to shoot about 50 feet or even more.

So what can I do to increase the range of my gun? I tried in sticking straws just before the ball valve, and while they stayed there well (as long as the nozzle wasn't too big) they didn't really seem to help stream lamination at all. I can get pics of my gun if need be. Thanks in advance.

Pics would be very helpful. How large are your pcs and what size is your pump? To be honest, my homemades only get range in the mid to upper 40s, 50s when the pc [s] is/are larger. My modded guns still whip my homemades in terms of range and stream speed. The funny thing is while I can get modded guns into the 60s, I can barely get homemades into the 50s. The biggest factor is definately pc size [and how well sealed your pcs are].

Edit> Is your ball valve PVC or metal? That will really influence range, too.

Okay, I'll get pics as soon as I can. I have 2 PCs, both are 2"x9" long, and PC capacity is around 1000-1100ml (the pump gets ridiculously hard after that). The whole gun seems to be sealed properly, no audible hisses or leaking. And yes, I used a metal ball valve.

That's the size of my pump. ;)

I would have really liked to have used 3" pvc, but I'm sure I've ranted enough about the reason for not using it :P .

The choice of ball valve type has nothing to do with distance. In fact, in my experience the only real advantage to metal ball valves is their superior durability. What matters in this case is the pump size, internal diameter, and nozzle orifice size.

Your pump size is too large to get high pressure very easily. You can still cut off the pump at the base and add a small reducing coupler to get the size down to something about 1/2". Big Bee has told me that they use hydraulics equations to calculate how hard a certain pump will be. Most manufacturered water guns use a 5/8" pump, the same size as sch. 40 1/2" PVC.

The internal diameter is also a little small for a homemade water gun. In your next homemade water gun I would suggest at least 3/4" PVC. A larger diameter will get more flow through the system. Admittedly, this won't matter as much as the other two factors I mention, but it will help. My CPS homemade water gun only uses 1/2" PVC and gets at least 60 feet of distance for example. Brute force can give you the right flow speeds, but turbulence will be created.

The final thing I will mention is nozzle size. There is an idea nozzle orifice size of every pressure of every water gun. I have an old article on Super Soaker Central called "Streams" that is in bad need of an update, but it does explain how to calculate the ideal orifice size: http://www.sscentral.org/tech/articles/streams.php

Straws also won't do that much unless the flow is already turbulent. I didn't notice a single different between distance with straws and distance without on my old APH style homemade water guns, likely because there wasn't much turbulence. There are much better ways to get extremely laminar flow, such as Chris Bloch-style nozzles that Buzz Bee Toys may be using next year.

Thanks doom. Trust me, the pump size is fine, I don't really have any trouble getting to high pressure. The stream moves incredibly fast, much faster than any of my stock CPS'es, it just turns to small droplets and therefore doesn't go that far. Plus, 15mm pipe is the smallest size you can get in New Zealand.

I thought having a smaller internal diameter was good for laminar flow? You also mention that your CPS homemade clears 60 feet, with an ID of 1/2"...my homemade's ID is larger than that, so I don't really think that's a problem.

Well I finally got round to taking some pics of the gun. I also found (actually some friends of mine next door suggested it) that using hosing connectors for nozzles works really well. The max range with a 5/16" nozzle is around 55 feet now thanks to this...far better than screw-on endcaps. So I guess you could say that my problem has been fixed. B)

The completed gun.


The nozzle assembly...it's got a 3/16" nozzle in this pic, which gets about 52 feet.

Nice job! That thing looks awesome! A lot cleaner than my first homemade, and that nozzle assembly looks really nice. Those (brass?) one way valves are interesting. They look a lot less bulky than the plastic types. Update us with some stream pics perhaps?

I love the nozzles! Do they screw directly onto a male adapter, or onto some sort of hose attachment?

Thanks for your comments! The one-way valves are brass, they seem to be more common than plastic ones here in N.Z, and they are also less expensive. Plus they unscrew so I can use them later for something else if need be.

As for the nozzles, they just screw onto a male adaptor. Of course you have to get some reducers as seen in the pics, but the good thing is that all 3 'nozzles' of mine have the same sized thread. I therefore don't have to unscrew any of the reducers when I change nozzles.

Pics to come soon!

Really impressive. Those one way valves are beautiful. I know you're painting this beast, right? .....right?

I think it would look pretty slick with a sharp angle tan and green paint job. Also for some reason, whenever I look at it, I feel the urge to add a butt stock. I know it doesn't have enough kick back to warrant the addition of one, but I think it would look awesome and help to balance out the weight of the gun.

Great job!

Soak On

The nozzles and check valves are amazing! I also love those huge pcs, have you calculated the x value for the riot blast [no nozzles]? [30mL/second=1x] You could get over 70x output with those if they dump all that water in a second or less. Great job overall. B)

Argh, taking stream pics is difficult...especially with a homemade.

Heres one of the 3/16" nozzle:


And one of the 5/16" nozzle:


They didn't turn out quite as I hoped, but oh well.
As for the riot blast, there's no way this gun could get 70x. First, the ID is only 1/2" (I found out that 15mm and 1/2" fittings are the same thing) and second the PC capacity is only ~1100ml. It gets around 40-45x at the moment though.

I hadn't considered painting the gun until you mentioned it, but there's some changes I want to make to this gun first before I do that. Sounds like a good idea though!

Great shot pics! The gun is nice and clean, It makes building a homemade look easy! Your nozzle system seems to be working well, much better laminated than most endcap nozzles I've seen.

Awesome pics, I can see the difference in output between the different nozzles.

B)

Edit: I really like what you've done with the nozzle, not using screw-on endcaps greatly improves performance.

Tried something interesting today. I found a pressure gauge in my garage, and the threads are the right size that they screw directly into the nozzle assembly. So I was able to find out exactly how much water pressure I was able to put into the gun. I was pretty suprised...I found that pumping gets a bit more difficult than your average soaker at around 30-40psi, and yields a pretty solid blast. I can pump up the gun to 70-80psi without much difficulty, and if I pump the gun up *really* hard, I can get nearly 120psi. Riot blast at that pressure has one heck of a kick! :lol:

Neat! That is something I'm suprised no one's tried before. With that information, on can use GGDT, or something similiar, to find the optimal performance of a water gun.

I was measuring my 11k's PSI as part of a science fair project, but the pressure was not at all near that high. It was around 50.

It's CPS, so the pressure is going to be low. With air pressure guns, 70-80 is probably only slightly above normal.

Are you talking about homemades or stock guns? Your average air pressure SS probably wouldn't get past 40.

Stock. I'm going to disagree with you. CPS has lower pressure than air pressure. CPS keeps the water at constant pressure, not high pressure. I'd place my bets that stock air pressure guns get around 50-60 PSI.

No surprise here really. I've used a pressure guade nozzle before but never really said anything about it. I know that Pepper did this as well in his homemade water gun. I don't think that this is a new idea, but it certainly is an uncommon idea. There's lots of things that people do that no one hears about.

The GGDT won't work for this sort of thing. The GGDT is obviously meant only for solid projectiles and is also only meant to predict possible performance, not improve it. You also can't do much with pressure other than increase it in water guns to get improved performance (i.e. low pressure means low performance and low turbulance, likewise high pressure means high performance and increased turbulance). Ideal nozzle orifice size would be the only real optimization really possible, and Duxburian and I have been doing that for years.

It would be neat if someone could make a WGDT, but there are too many variables to make any predictions accurate. Stream cohesion would have to be calculated, and we know that depends on viscosity, turbulance from the water gun design and nozzle orifice, and many other factors we don't even know about yet. To me, time would be better spent making water guns.

As for CPS being lower pressure, that is a misconception. Rubber CPS has no pressure. Nothing is being pressurized. People have said I am wrong for saying that, but in reality it is true. Yes, the water molecules will be a little more tightly packed, but water is incompressible for our purposes so any actual pressure is near none. The rubber pushes the water stream out like a rubber band shoots a small projectile. Anything you see on the pressure guage is just the rubber pushing the water into the spring on the guage. That's not pressure, it is only force.

m15399, you are right about stock CPS having much lower pressure, or force; or whatever is correct under the laws of physics, than stock air pressure, but your numbers are a bit off.

Here are some links to the specifications for some water guns:
Super Soaker XP 110
CPS 1000
CPS 1500
XP 70

Although, I'll agree that GGDT was only meant for solid projectiles, and that predicting water stats would take a completely different system, the version of GGDT that I have does have a gun optimizer. Such a tool allows you to change the different specifications of your gun to improve the performance.

The links that Some Guy provided are partly what I was basing my statement off. Although I don't know how accurate those figures are (after all, look at their nozzle rating system), my homemade at 50psi has a much faster stream speed than any of my guns, air pressure or CPS.

Hey, sbell25, do you think you can write an article on the construction of this gun w/ pics for my new website? It is in great need of articles, and I think this would be a good one.

I'll see about that...I don't know whether I'd be any good at writing a full article about it...I'm flattered though! What sort of pics would you want in this article (sorry, that may sound dumb, but most articles like that have pics of the gun during the construction process...which I don't have).

Don't worry, it doesn't need to be a great article. Just make it in depth.
Best Advice: Just write in detail why you decided to build it, what materials you used, how you built it (not step by step, but some detail), and your results. Any pics you've taken would be great.

Thanks, Some Guy. I had no idea what pressures stock guns had, sorry. Just guessing.

Nice to see that the information will be utilized for lasting value. Any chance of pics and/or an article coming SM's way? ;)

Okay, I've got a 'final draft' of the article done. Still need to add pictures and output measurements at the moment. It's around 700 words not including the materials and stats lists. Do you guys want me to post it here?

If you want to also give it to SM, then yeah you can just post it here. If you want to e-mail me, my e-mail is wetmonkey442@hotmail.com

Thanks, again!

The article is on the site, though not linked yet from the articles page. Can I use some of the photos you provided on here?