Supercannon II Analysis

Homemade water gun threads that are notable.
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Vickers303
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Supercannon II Analysis

Post by Vickers303 » Tue Aug 19, 2008 5:00 pm

After several correspondences with Ben, I decided to create this thread about the Supercannon II. When I first visited SSC at May 2008, I ambitiously chose "the most powerful water gun yet" for an upcoming water war. After completing my Supercannon II at June, I began testing it for range, shot time, the like. One of my major problems was reliability, concerning the piston. After each shot over 70 psi, it became skewed. In addition, my dad and I designed the gun with a 4 foot length of 4 inch pipe, which was way too heavy for battle practicality. We were pretty pissed at this otherwise excellent design, so we sliced it open, trimmed it down to 3 feet of pipe, and added three nuts to the piston. Beautiful performance afterwards. Battle practicality in my water war was great, with a 1/4 nozzle providing useful compensation for output with increased power, range and shot time.

I added some features to Ben's design, such as:
- a straight line air intake system, to simplify design and costs
- a variety of nozzles, such as 3/8 inch, 1/4 inch, and 1/8 inch (although I haven't tested the 3/8 and 1/8 nozzles yet)
- a back pull ball valve and lever, decreasing the amount of time needed for opening and decreasing storage length.

Stats and pictures will be posted later.
Why isn't there a water gun armored vehicle yet?

Arsenal: Modded Supercannon, Backpack-modified Piston Gun, WBL, Storm 300 Pistol, and a whole slew of defunct soakers in the garage.

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SSCBen
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Re: Supercannon II Analysis

Post by SSCBen » Wed Aug 20, 2008 1:02 am

As I said earlier, glad you got the system working well.

I don't have much to say other than that I'm interested in your valve and lever and some more specific stats... post them soon. :p

ben@sscentral.org / Please read this before emailing or PMing me

Do not ask me water gun questions by email or PM. Please post the question at the forum. Private questions and suggestions are welcome by PM and email. Also, I do not sell or buy water guns online.

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Drenchenator
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Re: Supercannon II Analysis

Post by Drenchenator » Fri Aug 22, 2008 2:13 am

Wow, sounds great. Can't wait for some pictures of the final product.
The Drenchenator, also known as Lt. Col. Drench.

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Vickers303
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Re: Supercannon II Analysis

Post by Vickers303 » Fri Aug 22, 2008 4:15 pm

I'll try to get some pictures by this weekend ... Sorry for the delays. My dad took my camera. Thanks for waiting!
Why isn't there a water gun armored vehicle yet?

Arsenal: Modded Supercannon, Backpack-modified Piston Gun, WBL, Storm 300 Pistol, and a whole slew of defunct soakers in the garage.

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Vickers303
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Re: Supercannon II Analysis

Post by Vickers303 » Sat May 30, 2009 12:43 am

Wow, it's been almost a year. I apologize deeply about the delays, I had some major academic and social work that came with junior year of high school. Here are the pictures from last year. All of the test shots were about 60-70 psi (I used a bicycle pump to charge, I was mad weak back then), but I have tested out the cannon this year. It fires beautifully at 80 psi (about 70-80 feet with the red fire hose nozzle) and I cannot wait to try it out at 120 psi.

Also, I still need to take pictures of my "modifications," consisting of the reversal of the ball valve pull and the addition of a small, "battle practical" nozzle, which is basically a 3/4 inch brass nozzle attached to a threaded 1 1/2 inch cap.
Attachments
Supercannon3.jpg
Supercannon2.jpg
Supercannon1.jpg
Why isn't there a water gun armored vehicle yet?

Arsenal: Modded Supercannon, Backpack-modified Piston Gun, WBL, Storm 300 Pistol, and a whole slew of defunct soakers in the garage.

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Silence
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Re: Supercannon II Analysis

Post by Silence » Sat May 30, 2009 2:16 am

I'd forgotten about this, so thanks for following up on this. :cool:

What range do you get with the other nozzle? Is it a conical or fire hose nozzle, like the large one?

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Vickers303
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Re: Supercannon II Analysis

Post by Vickers303 » Sat May 30, 2009 2:36 am

The other nozzle is a 1 1/2 inch threaded cap with a 1/4 inch hole drilled into it. At about 60-70 psi, it got about 80 feet. However, during this year's test, I charged the cannon to 80 psi, and it fired over my neighbor's garage. I didn't want to trespass, but my dad, who was watching and has an excellent eye for measurement, swore it was about 100 feet. I probably need to test it again, on the road next to my house.

I honestly think that the Supercannon is battle practical. With the 1/4 inch hole, the shot time was near ten to fifteen seconds. With a smoother valve, tap shots are very possible, and smaller nozzles could get extreme ranges and excellent soaking power. However, as Ben said before (somewhere, I don't recall), there are limits, but the Supercannon comes near to the max range a water weapon can have.

Would it be feasible to create an assault variant for the supercannon? I'm thinking of a 2 inch diameter chamber with a nozzle size of 1/8 inch, and a pump at the back for field charging. Reloading could be a problem, but the range and power could be worth it.
Why isn't there a water gun armored vehicle yet?

Arsenal: Modded Supercannon, Backpack-modified Piston Gun, WBL, Storm 300 Pistol, and a whole slew of defunct soakers in the garage.

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C-A_99
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Re: Supercannon II Analysis

Post by C-A_99 » Sat May 30, 2009 3:37 am

So far, the LPD is the closest to an assault version of the Supercannon. (which is buried amongst one of the threads here) LPD = low pressure dropoff, done by giving a high air to water volume. Unfortunately, this also results in a bulkier and heavier homemade, but the results are pretty impressive, achieving very close to CPS stream performance. The 2 in diameter of the design does limit capacity and power though, but the onboard pump system recharges it easily. (or would recharge it easily, if I didn't place the ball valve like I usually do, which now gets in the way of the pump, I'm going to have to make a special handle to the pump) The air portion of the system is powered by a schrader valve.

Theoretically, you could fully load up the water part of the system, pump in a lot of air (to the point where water can't be hand-pumped in anymore), get a good few shots out of it, then release the air until its down to 60 PSI or lower to make for easier pumping. The power level is pretty flexible for those who want higher PSI's and more range, or lower PSI's and less pumping

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cantab
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Re: Supercannon II Analysis

Post by cantab » Sat May 30, 2009 1:29 pm

Vickers303 wrote:I honestly think that the Supercannon is battle practical. With the 1/4 inch hole, the shot time was near ten to fifteen seconds. With a smoother valve, tap shots are very possible, and smaller nozzles could get extreme ranges and excellent soaking power.
It's practical as long as you don't need to field-reload. So if you play short skirmishes, it should be fine, but if you go for lengthy battles, it could be a problem - though you could use tactics that only require it once.
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
Water Warriors: Jet, Sting Ray M, Shark, Argon M, Tiger Shark, PulseMaster
Others: Waterbolt, The Blaster, Storm 500, Shield Blaster 2000, generic PR gun, generic backpack piston pumper (broken), 3l garden sprayer M, 10l water carrier:

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Vickers303
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Re: Supercannon II Analysis

Post by Vickers303 » Sat May 30, 2009 6:21 pm

@cantab- The last time I measured the capacity of the Supercannon, it held about six or seven liters (this was during an actual field-reload, when I used up my entire team's water supply in seven coke liter bottles). After reloading, I used up the water in one shot and took out my opponent's entire team. That was awesome. My only concern with using a smaller nozzle is that the stream could be too dangerous (smaller hole, more stream velocity, very real danger of accidentally hurting somebody). Is there any way to resolve that problem without reducing effectiveness?

@C-A_99- I looked through the forums for the LPD and I couldn't find any diagrams of the gun. Are there any? Maybe I didn't look hard enough. Sounds great, though.
Why isn't there a water gun armored vehicle yet?

Arsenal: Modded Supercannon, Backpack-modified Piston Gun, WBL, Storm 300 Pistol, and a whole slew of defunct soakers in the garage.

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C-A_99
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Re: Supercannon II Analysis

Post by C-A_99 » Sun May 31, 2009 12:07 am

Heres the whole thread which I was too busy at the time to find. I'd recommend reading the first few posts and skipping to page 4 for the pictures.
http://forums.sscentral.org/t5149

For safety, a smaller stream will break up even more, making it safer at attacking range, but is also more dangerous at close range before the stream breaks up. However, having no personal experience of anything that can shoot as powerfully, I wouldn't know. I'm also a bit surprised that dropoff is not much of a problem; perhaps the high pressure allows for that, though it really depends on how much space you give the air.

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Silence
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Re: Supercannon II Analysis

Post by Silence » Sun May 31, 2009 12:35 am

The stream won't go faster through a smaller hole. You're thinking the output is constant, regardless of aperture size; in practice, it's velocity that's fairly constant, and output changes instead. If that makes sense.

You will lose some range though. :cool:

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SSCBen
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Re: Supercannon II Analysis

Post by SSCBen » Sun May 31, 2009 9:56 pm

Nice photos. Glad to see you back Vickers.

I'm planning a revision of my original Supercannon II that should potentially address the questions of battle effectiveness. Take a Supercannon and attach a large HPA tank meant for paintball. You'll have a water gun with enough energy for 20+ full tanks at 65 to 70 feet of range easily.

I'm also planning some serious changes to the LPD water gun I made that CA99 now has. What I made was experimental and not very successful in my opinion. But it is interesting nonetheless and a good start.

LPD in short: High air-water ratios mean that the pressure drops less. With a 2.5:1 or higher ratio, the system functions about as well as rubber based CPS systems.

ben@sscentral.org / Please read this before emailing or PMing me

Do not ask me water gun questions by email or PM. Please post the question at the forum. Private questions and suggestions are welcome by PM and email. Also, I do not sell or buy water guns online.

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Vickers303
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Re: Supercannon II Analysis

Post by Vickers303 » Sun May 31, 2009 11:27 pm

@cantab- Thanks. I did not want to hurt anyone with the cannon, and I'm glad that, with some discretion, it can be used with a more focused stream safely. A little note: When I used the Supercannon in a water war once, I fired it point-blank (about three feet away) without any nozzles at an opponent that was just around the corner. Fortunately, he wasn't hurt at all, just completely soaked. I guess the supercannon is safer than anticipated. All the same, discretion is needed.
- About dropoff, there isn't really any. I use a 60-40 proportion of air to water, so range remains relatively constant until the last few miliseconds.

@Silence- Hmm. Maybe, it's just my elemetary physics knowledge, but I thought d=vt? With smaller nozzles, the cannon appears to fire further. I know that output changes with nozzle size, but wouldn't velocity increase as well? I'm confused ...

@Ben- Thanks, Ben. Is the Supercannon II mk. 2 going to use similar construction as tha first Supercannon II? One of the few flaws that I have found with the Supercannon is the reload time. My fastest time in battle, with letting out air, pushing the piston back, filling it up, and recharging took a good three minutes or so. It seems like you're adding a bigger air tank, but can't the same effect be seen with a good air compressor? I'll take a look at the new thread. Diagrams would be very helpful. Also, I might try to make an LPD myself. Looks very promising and has a sweet design.

I'm just wondering about limits to range. I know that higher pressures are proportional to higher ranges, so wouldn't it be possible to build an outrageously high-pressured gun and make a super sniper rifle or artillery gun? Just wondering.
Why isn't there a water gun armored vehicle yet?

Arsenal: Modded Supercannon, Backpack-modified Piston Gun, WBL, Storm 300 Pistol, and a whole slew of defunct soakers in the garage.

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Silence
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Re: Supercannon II Analysis

Post by Silence » Mon Jun 01, 2009 2:53 am

In general, sure, more stream speed will give you more range. The problem is that a narrow opening doesn't give you more velocity – just a narrower stream. A huge nozzle can be bad if the rest of the tubing constricts flow (which is not a problem with Supercannon II). A tiny nozzle is bad because thin streams break apart and slow down more quickly.

The relationship between pressure and range, sadly, is nowhere near linear. Overall, you'll see severely diminishing returns. Here's the breakdown of the physics:
  • Flow/output/velocity is proportional to the square root of pressure.
  • Fortunately, range is roughly proportional to the square of velocity.
  • However, because water is lightweight and lacks cohesion, wind resistance breaks up and slows down streams rather quickly. Why does a CPS 12.10k have more stream speed but less range than the CPS 2000? Why is it that a water cannon hit at 50 feet feels like a spray of water, while a hit at 10 feet could easily bruise you? In the end, it takes a lot of energy, mostly used at the beginning of the trajectory, to get a noticeable increase in stream speed. Once again, of course, larger nozzles help – it's the reason that the CPS 2000 has more consistent stream speed.
A good air compressor will still take some time to pressurize the chamber, and you'll have to carry it around with you, somehow. Ben wants to carry around a canister containing a large amount of already-compressed air – it's portable and it pressurizes the water cannon instantaneously.

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