Super Soaker Central forums

Silence · 09-24-2006, 10:02 AM

Do what you wish with the gun bodies, but it is imperative that the minimum barrel bore for the guns is 1/2"! Preferably higher! I'd aim for 0.75"-1" if possible in order to maintain a compromise between looks and performance, but I doubt you'll need to go higher than that. Other than that, the actual design is up to you, and it would help to use linear flow--in other words, try to make sure the path of the water is a straight line and not a twisty one that goes through many unnecessary chambers--this gives smooth, laminar flow.

Given that the source of the water is central and elsewhere, the only things the gun bodies would need are a hose connection, a short barrel if you wish, and a trigger valve. A solenoid valve is fast-opening and can use a trigger, but it doesn't have laminar flow--but try to cancel the turbulence with a long barrel.

The tank size is okay, but bigger is better if possible. Go for at least 1/2" on the barrel. Even with those figures, we can't do precise calculations; but based on past performance, it's clear this thing will easily hit 50 feet. A smaller barrel, though, can really harm that. Perhaps somebody else can give some basic calculations...

Major Mallet · 09-24-2006, 10:51 AM

SilentGuy - OK, let's forget the 1/4" and go with either .5 or .75 diameter for the barrel. On the issue of tank size – 10 gallons is too small, eh? Obviously, bigger is better but I don't want to spend more on capacity I will not need. Anyone else have any thoughts on this?

Joannaardway – Do my last two posts give you enough to estimate system performance?

Also, does anyone have any insight on how barrel length affects the water force / reach / pattern?

Drenchenator · 09-24-2006, 11:24 AM

Quote:

QUESTIONS: OK, here come the math issues. How would I calculate how many seconds will each gun fire on this system? Can you mathematically estimate how far the water will travel? Assume that each gun has an 8 gallon water capacity (if my volume calculations are correct), will fire at 40-60PSI and have a ¼” nozzle at the barrel. Any opinions on increasing/decreasing PSI or nozzle size? Will a 10 gallon tank be sufficient for the task?

I used some of the basic equations for output to come up with this one just for this gun. t is of course time, L is the length in inches of each chamber (the equation already accounts for 4 chambers, the integers canceled out), and D is the diameter in inches. n is the number of guns and Q is the output (rate of flow) in ounces per second. 1.8 is the number of cubic inches per ounce.

Using this equation and some quick calculations by hand, I substituted in 5 ounces per second for the output and 3 for the number of guns. L was 36 and D was 4. The answer was 67 seconds. I also substituted in 1 ounce per second for each gun and got an answer of about 320 seconds (over 5 minutes). A medium sized nozzle should get around 5 ounces per second of output and a very small diameter nozzle should get about 1.

Silence · 09-24-2006, 01:58 PM

Barrel length has a minimal effect here, although there are charts that provide the exact amount of resistance--so don't worry about the length. Yes, in homemades we want short barrels, but that's only for convenience and a tiny bit for performance--it's not noticeable. The difference is in WBLs, in which a longer barrel allows for more time for the air to expand and the acceleration of the water balloon will last longer.

Drenchenator did some very nice calculations, but remember that that isn't much output. The XP 70 is the benchmark for 1X of output (if you already have a stock soaker, I can give you a comparison output in Xs--or you can check it out at iSoaker.com), with 0.93 oz/s. That's pretty low for such a huge system, and chances are you'll need 10X-20X at least for the greatest range. The reason the CPS 2000, which is weaker than this system would be, is so high-ranged is because it has a huge 28X stream! Go for the large barrel in case you need a larger nozzle.

Drenchenator · 09-24-2006, 04:06 PM

Quote:

Drenchenator did some very nice calculations, but remember that that isn't much output. The XP 70 is the benchmark for 1X of output (if you already have a stock soaker, I can give you a comparison output in Xs--or you can check it out at iSoaker.com), with 0.93 oz/s. That's pretty low for such a huge system, and chances are you'll need 10X-20X at least for the greatest range. The reason the CPS 2000, which is weaker than this system would be, is so high-ranged is because it has a huge 28X stream! Go for the large barrel in case you need a larger nozzle.

I was just going by what on average would be a fair output. Though large outputs are a nice option, you will not always be shooting at those. Most of the time, you should have a fair output (~5 ounces per second) which would definitely pack a punch and last for a long time (one minute straight for 3 guns at once is very impressive). If each gun is shooting at 30 ounces per second, you can only get 12 seconds at most of shooting. Not very practical in my opinion.

Output and range are unrelated. You can technically fill a bucket with one gallon of water and "toss" the water to get an output of 1 gallon per second but a range of 10 feet. Good range is easy to get with low output; there is no need to have excessive outputs for high range. If a gun is powerful (like this one) and the nozzle is small enough, good range is definitely possible with low output. People seem to compare output to power, but output is not only determined by power, but other factors (internal diameter is a big one). Output is the rate at which water leaves the soaker, and that is it.

Quote:

On the issue of tank size – 10 gallons is too small, eh? Obviously, bigger is better but I don't want to spend more on capacity I will not need. Anyone else have any thoughts on this?

Just buy what you need, but buy longer lengths to save money (a 10 foot length of 4" pipe is 30.50 USD while a 5 foot length is 20.51 USD according to McMaster). If you want extra capacity, just make the tanks longer. If you use 5' lengths, you can buy 2 10 foot lengths of 4" pipe and use all of it. That should get you 12.5 gallons. If that is not enough, all that I can recommend is extra tubes (maybe 6 instead of 4) and make those 5' long.

Silence · 09-24-2006, 05:02 PM

Yes, that makes more sense and it's what I originally thought, but it seems as if stream speed slows down due to increased drag for smaller streams--check out XN's article. How else would you explain that medium, optimized nozzles get the best range? Also, part of it is the fact the output != area * speed.

joannaardway · 09-25-2006, 05:38 PM

I'll try and get going on the maths...

*wanders off to find calculator*

09-24-2006, 10:02 AM	#16
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,285 UserID: 576	Do what you wish with the gun bodies, but it is imperative that the minimum barrel bore for the guns is 1/2"! Preferably higher! I'd aim for 0.75"-1" if possible in order to maintain a compromise between looks and performance, but I doubt you'll need to go higher than that. Other than that, the actual design is up to you, and it would help to use linear flow--in other words, try to make sure the path of the water is a straight line and not a twisty one that goes through many unnecessary chambers--this gives smooth, laminar flow. Given that the source of the water is central and elsewhere, the only things the gun bodies would need are a hose connection, a short barrel if you wish, and a trigger valve. A solenoid valve is fast-opening and can use a trigger, but it doesn't have laminar flow--but try to cancel the turbulence with a long barrel. The tank size is okay, but bigger is better if possible. Go for at least 1/2" on the barrel. Even with those figures, we can't do precise calculations; but based on past performance, it's clear this thing will easily hit 50 feet. A smaller barrel, though, can really harm that. Perhaps somebody else can give some basic calculations... __________________ Forum rules

09-24-2006, 01:58 PM	#19
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,285 UserID: 576	Barrel length has a minimal effect here, although there are charts that provide the exact amount of resistance--so don't worry about the length. Yes, in homemades we want short barrels, but that's only for convenience and a tiny bit for performance--it's not noticeable. The difference is in WBLs, in which a longer barrel allows for more time for the air to expand and the acceleration of the water balloon will last longer. Drenchenator did some very nice calculations, but remember that that isn't much output. The XP 70 is the benchmark for 1X of output (if you already have a stock soaker, I can give you a comparison output in Xs--or you can check it out at iSoaker.com), with 0.93 oz/s. That's pretty low for such a huge system, and chances are you'll need 10X-20X at least for the greatest range. The reason the CPS 2000, which is weaker than this system would be, is so high-ranged is because it has a huge 28X stream! Go for the large barrel in case you need a larger nozzle. __________________ Forum rules

09-24-2006, 05:02 PM	#21
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,285 UserID: 576	Yes, that makes more sense and it's what I originally thought, but it seems as if stream speed slows down due to increased drag for smaller streams--check out XN's article. How else would you explain that medium, optimized nozzles get the best range? Also, part of it is the fact the output != area * speed. __________________ Forum rules

09-25-2006, 05:38 PM	#22
joannaardway Do not adjust your TV set Join Date: Feb 2006 Location: SW Hertfordshire, England Posts: 875 UserID: 549	I'll try and get going on the maths... wanders off to find calculator __________________ "Over the hills and far away, she prays he will return one day. As sure as the rivers reach the seas, back in his arms again she'll be." - Over the Hills and far away, Gary Moore "So many people have come and gone, their faces fade as the years go by. Yet I still recall as I wander on, as clear as the sun in the summer sky" - More than a feeling, Boston

09-24-2006, 10:51 AM	#17
Major Mallet Junior member Join Date: Sep 2006 Posts: 7 UserID: 868	SilentGuy - OK, let's forget the 1/4" and go with either .5 or .75 diameter for the barrel. On the issue of tank size – 10 gallons is too small, eh? Obviously, bigger is better but I don't want to spend more on capacity I will not need. Anyone else have any thoughts on this? Joannaardway – Do my last two posts give you enough to estimate system performance? Also, does anyone have any insight on how barrel length affects the water force / reach / pattern?

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