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Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Wed Jul 27, 2011 7:39 am
by IcarusXR
Hey everybody, so this is my first time posting on the forum, and I had an idea for a simple modification to an existing gun (CPS2500) to make it auto-pressurizing. I call it the 'Icarus Mod'.

The Backstory/How I wound up here:
Earlier in the year I was informed that our squadron would be holding a Dining-In. This is basically where a bunch of air force guys put on camo uniforms and go eat MREs in some shady venue. However, this year one of the officers who is overseeing the event wanted everyone to bring a water gun, and for there to be squirt gun battles over dinner (don't ask me why...) So being the inventor that I am, I decided that I would go for something a little geekier and crazier than the average guy. I came up with the idea for a huge, intimidating, automatically pressurizing super soaker powered by 300psi CO2 gas (yeah, I'm a mad scientist =P) Anyway, when I was younger I had a stock of super soakers so I figured that one of those would work nicely, but not wanting to ruin a cherished childhood heirloom I decided to go to target and pick up one there for cheap. Unfortunately, I learned that the 'good old days' of the super soaker brand were long past and they no longer made the CPS series and they're now selling on Ebay for like $200 (I was like wtf...)
SO I grabbed my old CPS2500 and I got to work:

The Mod:
So the first thing I did after I grabbed my old CPS2500 was I decided to paint it to look more appropriate to be carried around at a military event.
Yes, that's the hood of my car under the CPS =)
Then I gathered the necessary materials for the mod. I have images of them but I have found image sharing sites tend to delete images after time so I have listed the components as well. I also bought some 12g CO2 canisters but you can get those at any sporting goods store. You can also use the large paintball CO2 canisters as well.
- Miniature 1/8"NPT brass miniature air regulator 5-50psi range
- Brass 90deg elbow 1/8"NPT-1/8"NPT male pipe fitting
- Paintball quick change 12g CO2 adapter
- Paintball CO2 fill adapter remote on/off 2 port gauge
- 6" SS braided hose

To be continued... I'll post more pics of the mechanism/firing when I get it all assembled. Basically all that's left to do is assemble the thing, adjust the regulators and drill a hole into the CPS2500 reservoir for the braided hose, seal it up and the thing should pressurize itself =)

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Wed Jul 27, 2011 3:06 pm
by atvan
Noooo! This will not work. 300 psi will break the thing, and regulated, it will just ruin firing angles and create drop-off. Unless you plan to just pressurize the reservoir, which is no good because it is not designed for pressure. Bad idea. An it's a 2500. I'm sure that there are peoplewho would help clear out space, buying some guns.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Wed Jul 27, 2011 3:11 pm
by DX
This project looks cool, except for one thing: Why are you using CO2 to power a CPS gun? They don't use pressure...they use the elasticity of the rubber bladder to expel water. CPS pumps are designed just to fill the bladder with water, the bladder contracting forces it out. Putting any air in there breaks up the stream, see the topic of MK1 2000 vs MK2 (even a little bit more air makes a noticeable difference).

If you're piping CO2 into the reservoir, you're just making a PR gun that doesn't require CPS or even a separate firing chamber. It's a waste of a CPS 2500. You will also have to change the firing system a bit, since the 2500 is designed to put water in a separate chamber. Unless, of course, you intend to leave the rubber bladder in, which 300 PSI would blow up because it can't handle that. Actually, half that amount is probably enough to blow up any part in the gun. CPS PC's can't hold the pressure either, the casing has holes to actually vent air, because again, it's the rubber doing the heavy lifting and not pressurized air.

If you want to make CPS auto-filling, you'd need to make a homemade quick fill system (like VHS) and adapt the 2500 to use it. It's water you want to pump in, not air.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Wed Jul 27, 2011 3:17 pm
by atvan
I think he is regulating CO2 into the reservoir, which pushes the watre into the CPS chamber. Just get some arm exercise and pump the damn thing!

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Wed Jul 27, 2011 5:47 pm
by New Guy
I for one am curious to see how this turns out. I'm a huge Suzuki fan and some jerkoff took a MINT Samurai and cut it in half to use as an offroad trailer behind his Jeep, which he rolled two months later. That was something worth getting upset over, as there were far fewer Suzuki Samurais than there were CPS2500s.

What people do with their money is their call. I'll admit, I'd prefer he used something such as the Hydro Cannon, which would make an awesome automatic weapon.

Edit: Speaking of, IcarusXR... Why not use a Hydro Cannon? They look more intimidating than a CPS2500, you gotta admit, and can be had for as little as $20.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Wed Jul 27, 2011 8:07 pm
by zeda.beta
The concept is interesting, but I wouldn't pursue this with a cps gun. Try an air pressure gun, like the newer vanquisher, as with the current setup all you would manage to do is break the pressure chamber.

Edit: I figured out that the CO2 would be used to force the water into the pressure chamber, but the problem with that is the CO2 would only ruin the current setup of a compressible material forcing the water out of the barrel a.k.a preventing the gun from firing any faster than it already does. You would be able to pull this off with an ap gun as I said earlier, but the CPS gun would just be ruined beyond recognition.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Thu Jul 28, 2011 12:40 am
by IcarusXR
Two words guys: check. valves. A large part of the system and understanding of the system relies on the strategic use of the gun's own internal check valves to do what I want. The guy who had my idea most correct was actually atvan, who said "just get some arm exercise and pump the damn thing!" And I fully agree that exercise is good, but when it takes 40 pumps to get the thing charged again, it goes from yay exercise to just looking stupid - and you cant fire while you're pumping so theres strateger-y involved with having a gas operated pump instead of having a hand operated pump.

In response to all the collectors who are like: omgggg you are ruinnning a pricelesss artifact!! You do have a point. But notice that I did not actually pay for the gun, I had it from when I was a kid, going to target to get another gun when I already had a perfectly good CPS2500 is a waste of $35. Yes I could have sold the CPS2500, or saved it for later years, but I chose to mod it.

Anyway. Back to the actual story. So today I got around to actually test firing it for the first time in like 10 years and learned that it was completely FUBAR. The trigger literally broke off in my hand on the 3rd firing, the pump squeaked like an 80 year old grandma's brake pads, and the stream was literally the most turbulant and uncollimated mist I've ever seen - not at all like I remembered the thing. SO today I went to work fixing the numerous problems before installing the new stuff.

First I worked on the laminator. This was probably the easiest part of the gun to figure out once I got the screws off. It consists of (unlike an air laminator), two dirt clogged wire screens and a matrix of cheap drinking straws stuffed in between them. I grabbed a fluids textbook and realized that the guys designing this gun did not do their homework. They had the tube size wayyyy too big, and the tubes too short to fully collimate the flow. So I upgraded to coffee straws.
Then I cleaned off the dirt from inside the screens, chucked the old white crap tubes and stuffed the new tubes in a tight cluster and sealed the laminator back up again. Should be good as new and water tight! =)
Then there was the trigger breakage. After a little reading I realized that this was a common flaw with the gun again due to (wow this was really a surprise) bad engineering. I clamped it back together and epoxied it up, should be good as new in 24 hours.

Finally there was the squeaky pump. Easiest fix of the bunch, just lubed it up with some vasoline and slid it back in.

Then while I had the whole thing disassembled I had an idea. I figured - if I'm going for optimum flow rate, I might as well replace the nozzles because an orifice plate isn't exactly the most laminar thing in the world either =) So (and I know you guys are going to just cringe when I say this) in order to improve the nozzles, I had to first make all the holes the same size.
Sanded it down and here's how I'm gonna leave it for tomorrow.

I apologize again for not fully explaining the "300psi CO2" mechanism of action, but I assure you that I will explain it fully when I install that either tomorrow or the day after =)
I will also be putting the whole gun back together and attaching the optimized laminar nozzles tomorrow or the day after as well. Thanks for the advice everyone!

Also, I am still debating where to put the CO2 tank and regulator... I am thinking somewhere near the top carrying handle might be best, but since I already have the gun open I was actually thinking inside the grip handle might work as well - and it would look much more stock that way. What do you think?

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Thu Jul 28, 2011 1:06 am
by atvan
Vaseline may degrade the rubber o-ring in the pump. Of course,vit might not, but it would have been best to not take the chance. I guess it is too late now. What is wrong with the laminar flow of a nozzle selector? The way it works doesn't create any bends, so please explain the problem.

Side note: if you inherited a Van Gogh painting that an ancestor got for cheap when he was alive, does that make it any less valuable?

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Sat Jul 30, 2011 3:47 am
by uberninja333
i say let him try this, but i would try to find another cap and mod itto atach to the resivwar. i think it would make more sense, and you could atach it to another gun, such as a cps 2000. i wish i thought of this.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Sat Jul 30, 2011 1:26 pm
by SSCBen
Welcome to the forum IcarusXR!

This project sounds interesting. I can see a few ways this could be done with common pneumatic components, so I wouldn't discount the idea completely.

I personally would make the water gun completely homemade instead of using this, though, but that's just my personal preference. To each their own.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Mon Aug 01, 2011 12:50 am
by zeda.beta
Ohhhhh, I thought you were using the CO2 to directly pressurize the chamber. Now I see that it could work very well indeed. Seems like a waste of CO2 pressure, I would have used an electric piston instead.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Tue Aug 02, 2011 10:19 pm
by uberninja333
he could fill the co2 canister with air after using it. then he dosent need to buy more. airgunners do the same thing with their co2 canesters.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Tue Aug 02, 2011 11:21 pm
by marauder_4
This is... interesting.

There are a few ergonomic reasons I still prefer mods to homemades. The main reason is the fact that I still have yet to see a home made trigger design that is as ergonomic as a super soaker/water warriors/etc trigger.

While we're on the subject of CPS 2500s. Has anyone ever replaced the CPS bladder or done a collossus/check valve freeze on a 2500? What kind of range increase does it get?

Can't wait to see how it turns out.

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Wed Aug 03, 2011 7:46 pm
by -G-JiV-
Hm. This "new" idea is nothing now to me. Sometime ago, I think the last month, I put a check valve into a CPS 2500's reservoir cap and sealed everything. Then I filled the 2500'Äs reservoir with water, screw up the cap and put pressure(air) into the tank. Obviously the chamber refilled automatically. By leaving about 8 bar, which is over 130 PSI I think, I made the PC refill automatically after firing. This way I fired out the whole reservoir volume without any pumping.

Yes, it is a nice idea, for sure. It works nice. Using a CPS 2500 cap was a good idea too, since I can use it for the 2000 Mk2 and Mk1 too. O well, a CPS 2000 Mk1 that refills automatically...haha

This is a nice thing, a bit much work since you have to leave the pressure out, refill with water and then put in air-pressure again. But in the end you just get a weaker versions of the "POWER PAK" ... no reservoir but water can be fired till all is out.

It works well, but honestly I like pumping the good cps guns. It makes much fun when all people are firing and refilling/pumping and firing again. THe party is over in just a few minutes when all guns are firing out 3 litres of water and more, well...

People are complaining about pressure, so they get a seperate PC. They are complaining about pressure-drop of, so they get CPS. THey are complaining about lack of reservoir volume, so they get CPS 3000/3200. They are complaining about lack of PC volume, so they get Monster XL. They are complaining about so much weight and so much pump to refill, so they get a SC POWER PAK. Then they are complaining about so much time to refill/need of QFD and hose. THey do not like pumping but also not refilling ny QFD.

Now we are building pressurized reservoirs, to make the gun refill itself.

My question now, why we do not just use a HOSE to soak each other or better, use a FIRE_CAR ? ...

If you ask me, the traditional pumping is a cool thing, and although it is a bit exhausting after a long time, it is a nice part of water warfare and it should always be one :) Technical Progress does not mean that things are getting better by saving power and time...The better something is getting, the worse an other thing will get...

It is also dangerous to put in pressure into the reservoir, since it is not built to handle pressure! 150 PSI is right enough at a 3/4 with water filled reservoir !!

I am using it every now and then but not that often.

Besides all, funny to see that someone got the same idea, hehe :) I can help if help is needed though ^^

Good luck and be carefull, HIGH pressure is HIGH DANGEROUS too !

Re: Icarus Mod - CO2 Based Automatically Pressurizing CPS2500

Posted: Wed Aug 03, 2011 8:05 pm
by wetmonkey442
^Everything that G-JiV said was 100% correct and everyone should be forced to read it. Very wise statements about homemades, modifications, and water guns in general.

Soak On!