Spring Based CPS

[Teh Moron]

Ok, while looking at an internal pic of a pressurized CPS 2000, I got an idea for a homemade. Why not have a closed cylindrical chamber with a metal pole, a reinforced rubber disk with a hole in the middle designed to create a perfect seal between the pole and the chamber wall and a spring pushing on the rubber disk to create pressure? It wouldn't be CPS, and there would be some dropoff at the end, but it would be damn close.

[HBWW]

That would still create a lot of stress on the rubber, and getting the seal could be very hard because of how the rubber expands. (the rubber must be hard-attached to something non elastic, otherwise the rod has to be able to move) The closest to this was someone who tried a spring mod on a WW gun, but the mod pretty much destroyed his PC.

Looks like rubber disk (by itself), spherical rubber, cylinderical rubber, and compressed spring are the only options right now for CPS. (other than the CAP systems, etc.)

[Teh Moron]

Well, there would be a metal plate behind the rubber to reinforce it, of course..

[SSCBen]

Most springs don't apply constant force, therefore the pressure won't be constant. It can be really powerful, but it won't be CPS with a standard spring. It'll perform similarly to air pressure water guns, however, the spring PC is different in it can be fired at any angle.

However, some springs are near constant force. Conical compression springs are the ones to look for. I brough this up just a day or two ago here. In fact, I thought this thread was just a continuation of the comment I made in an earlier thread!

You can use a simple dual piston seal and spring combination to make a constant pressure spring pressure chamber. Not a problem at all. Let me know if you want a detailed parts list because I could write one up pretty easily. I actually was researching this today!

CA-99 is correct that there would be a lot of stress on the rubber. The spring mod for Water Warriors Hydro Power water guns was did put a lot of stress on the rubber disk that powers those water guns. The modification did not destroy the PC however. The guy who did it just didn't feel it worked correctly. I don't really quite remember the exact reasons other than "it doesn't work well."

The piston cups I have used in a piston water gun of mine are rated to 3000 PSI. That makes them stronger than the plastic pipe the water gun was constructed from. So, in a homemade version of this I wouldn't even worry about breaking the rubber. I'd use a metal washer anyway, but it really isn't anything to worry about.

With this being said, a few months (okay, about a year) ago I wanted to make a spring powered water gun that operated on a single pull... the idea was really cool but I never got around to it. I have too much I want to make in reality!

[Teh Moron]

Ah, thank you for clearing that up. I thought any compression spring with washers on the sides would work.

So would it be possible to make a modified APH with spring powered PC's instead of the air powered PC? And how much money would it cost to make 1 pc?



Edited By Teh Moron on 1182473088

[HBWW]

^That's basically what the spring based system is, there has to be a piston there for the spring. What I think you mean is having both in one chamber, the spring pushing on it and the air adding to it, but that's not constant pressure.

[SSCBen]

So would it be possible to make a modified APH with spring powered PC's instead of the air powered PC? And how much money would it cost to make 1 pc?

I'd imagine that for a spring powered pressure chamber to be comparable to a higher end air pressure homemade, the spring would have to be able to put out about 500 pounds of force. That's based upon a 3 inch pressure chamber (like the APH) and trying to get 70 PSI, about three times the pressure of normal CPS water guns. If you want 100 PSI, you'll need about 700 pounds of force.

Higher force springs can cost a lot. I'd imagine you'd pay up to $20 alone for the spring! The pistons would cost $15 too! That doesn't include the price for the PVC or bolts and nuts even. You'd be paying $50 to $60 for this pressure chamber. Would it be worth it? If you want a very high powered water gun, I would say yes. It would be more expensive than both the other viable homemade CPS options, constant air pressure and latex rubber tubing, but it would be more powerful than LRT and more versatile than constant air pressure. I definitely see potential in this.

Now if the manufacturers jumped in on the spring CPS idea, tha would be a great way to avoid Hasbro's patents. Manufacturers essentially can custom order the parts they want. And in bulk, they'd be cheap. They also don't need have pressure ratings quite as high as we do because they're not looking for elevated performance. To achieve 30 PSI on a 2-inch diameter chamber, they'd only need to put a spring capable of 100 pounds of force, a far easier and cheaper task than the spring we will need.

If you want quick, cheap, and powerful homemade CPS, just use latex rubber tubing. Every day I am surprised that people choose not to make water guns this way. You can get the upper 50s in range pretty easily, just using two layers of LRT and a bunch of layers of bike tubes. Now, getting beyond there takes a lot of effort and I think that's where spring-based CPS should come in. I have tried to ask rubber tubing manufacturers about extremely thick latex tubing, but they all tell me it can't be done. I don't have a technical reason as to why it can't be done, but they consistently have said it is hard. I have been investigating a device to make stacking LRT easier, but that's not out of the planning stages yet.

Now, if you'd like to jump on the spring CPS idea, I'd have a few suggestions and tips to help get your started. First off, join the forum linked to in my signature. Not much homemade water gun discussion occurs here and if you're interested in that aspect of water guns, I think you'd feel right at home at my forum. Secondly, check out Vanel. I've never used their website for anything before, but they appear to have springs capable of what we are looking for. Normally I would suggest McMaster-Carr, but they don't have too many conical springs.

Once I finish my current project (not water guns, but fun nonetheless), I'll start investigating a spring based water gun more seriously. :;):

Edit:

I just checked out that Vanel website. They don't offer anything close to what we're looking for. Some other manufacturers might offer what we're looking for.



Edited By Ben_ on 1182515677

[Dacca]

if going after a spring based cps device why not go for a similar method to what WW did with the steady stream. inwhich water feeds into the pc and pushes back on disk which pushes the spring creating pressure. it works really well for the steady stream, and im sure it could somehow be used in a non piston based soaker. but the drawbacks have already been stated sooooo yeah....

[Teh Moron]

I've checked it out too. The prices aren't too high for the more basic models, but look at the price list. It says that orders of 1000 or more get a 98% discount. It also lets us customize the size and type of spring. Where did you get your estimate for the post above? I'd imagine that even the higher powered PSI springs wouldn't cost $20.

EDIT: @ Dacca, that's what we're trying to do. Basically how the system works is that there is a rubber disk inside a piston being pushed on by a spring. When water enters the chamber, the spring exerts force on the rubber disk. It's sorta like Buzz Bee's Hydro Power with a spring mod, but draws more power from the power of the spring, rather than a diaphragm. You might want to ask Ben; he seems to have already researched this method of water propulsion.

@Ben, are there any more details about the spring mod? I can picture the rubber bladder expanding around the spring, but not on top of it. Did he use a washer? And were they a weaker version of the springs you told me about?



Edited By Teh Moron on 1182540649

[SSCBen]

if going after a spring based cps device why not go for a similar method to what WW did with the steady stream. inwhich water feeds into the pc and pushes back on disk which pushes the spring creating pressure. it works really well for the steady stream, and im sure it could somehow be used in a non piston based soaker. but the drawbacks have already been stated sooooo yeah....

The Steady Stream isn't CPS. It's a way to make piston based water guns have no interruptions between pumps. It's essentially a regular water gun with a spring-based pressure chamber and no trigger/valve system. There's no reason to use this system in another water gun because it doesn't make anything more constant, rather, it helps remove the interruptions between pumps.

The spring used is a normal spring also. We need a conical one because those are the only ones to apply more constant force. To reiterate, regular springs apply variable force. A regular spring would perform similarly to air pressure.

I've checked it out too. The prices aren't too high for the more basic models, but look at the price list. It says that orders of 1000 or more get a 98% discount. It also lets us customize the size and type of spring. Where did you get your estimate for the post above? I'd imagine that even the higher powered PSI springs wouldn't cost $20.

Okay, when you order 1000 springs let me know. Even if they make the springs we want cost $0.20, that's still a $200 order. A lot just for a few springs. Believe me, we won't be able to afford most bulk orders because we're not ordering a huge amount.

I based my $20 figure on actual prices. Higher force springs are somewhat expensive. If you want a spring that could apply 20 pounds of force, that wouldn't be too expensive, but it also couldn't work well in a water gun.

The ones they show in their product selection are pretty small springs that wouldn't be close to the kind of springs we want. And, they're not conical springs either. Take a look at the sizes listed there. A 100mm spring costs about $1.75 when converting from Euros. That's actually really expensive.

The fact that the website that claims to offer the largest selection of springs and it doesn't have larger conical springs isn't a good sign. I think some of the actual companies that produce these springs would have a better selection. I'll be emailing a few about what their capabilities are.

Vanel doesn't show prices unless you log in, which is just a plain bad idea because study after study show that people don't buy unless they know the price up front. Looking at McMaster-Carr, a good general purpose parts store, a 3 inch regular spring comparable to the one I described earlier costs $17 (part number 96485K249).

[Teh Moron]

I didnt say that I would order the springs...I was just reiterating what you said that if a manufacturer decided to take this idea, that it would be much cheaper to make (and probably less powerful) than if we were to make them as homemades. However, they might just decide to make the springs inhouse.. you never know.

[Dacca]

btw, although the steady stream is a piston soaker and not a cps soaker, the way the spring based pc works is literaly a cps even though it isnt a cps soaker. go figure.

[SSCBen]

I didnt say that I would order the springs...I was just reiterating what you said that if a manufacturer decided to take this idea, that it would be much cheaper to make (and probably less powerful) than if we were to make them as homemades. However, they might just decide to make the springs inhouse.. you never know.

Okay, well, I already knew that and said it. :;):

@Ben, are there any more details about the spring mod? I can picture the rubber bladder expanding around the spring, but not on top of it. Did he use a washer? And were they a weaker version of the springs you told me about?

Do you know how the Hydro Power system in the Water Warriors water guns works? Check this out for a picture: http://www.google.com/patents....mmerman

It uses a flat rubber sheet as opposed to an expanding rubber tube or balloon to create pressure. The flat sheet expands upwards. Adding a spring would add some more force, increasing the pressure. No washer was used, however, blaze (the person who did the modification) did say that he did protect the rubber with something, but I forget what he said. I'll have to find the IM conversation where he said it if it exists.

btw, although the steady stream is a piston soaker and not a cps soaker, the way the spring based pc works is literaly a cps even though it isnt a cps soaker. go figure.

Again, this is incorrect. CPS implies some sort of constant pressure. A normal spring applies a variable (changing, non-constant) force, which turns into a variable pressure. It works like a spring water gun. Spring water guns are not CPS generally unless they use a conical spring.

I haven't used a Steady Stream, but you should note a drop-off if you do one pump and watch the stream unless they used a conical spring. I don't think they did however because conical springs would be a much better rubber CPS alternative to their Hydro Power system.

[HBWW]

He's probably getting confused the CPS method of pressurization vs. the CPS line of guns. But if you go by their gun line, the FF, AB, etc. wouldn't be considered CPS either.

Looks like we might have to re-classify things, going by methods of operation. This could mean ditching CPS as a classification and replacing it with elastic, so we can include the Steady Stream on there as well as any kind of spring based gun. After all, CPS only implies constant pressure, not how the gun really works. It belongs in a different type of classification, away from air pressure, direct piston, etc.

Hmm... The spring idea doesn't seem to be that new, it's just that people wouldn't follow the idea due to concerns of rusting, piston seal, etc. (which piston seal can't be an issue since it isn't in those cannons) but didn't get on at all until BBT had the Steady Stream this year.

[Dacca]

i agree, cause itd prove that im right (j/k). but even true cps soakers have a dropoff at the end, even if is more limited. but i agree that when cps stands for 'constant pressure system' it is referring to the type of super soaker line, but if it were to stand for 'constant pressure soaker' then it can include hydropower soakers as well. the latter use of cps would be streched to include all non-piston and npn-air powered soakers that use some sort of elastic material for their PC.

[isoaker]

This thread has gotten me thinking about renaming things and/or re-organizing things. As Ben pointed out, the spring-based systems currently available have definitely more inferior overall performance than rubber-bladder or rubber-diaphragm counterparts. Conical springs would provide a more constant level of pressure against a plug. Changing the categorization name to something like "elastic" or "mechanical" pressure terms might be more accurate. If "mechanical" were used, it would also serve to classify direct motor-pump-based water blasters. However, I'm presently leaning towards "elastic" pressure.

Side note: the Splat Blaster also relies on a spring to create its splat, though it pushes out a rather small volume of water.

[HBWW]

^Yup, that's what I was saying earlier.

I believe elastic still works better, mechanical seems to be pretty general and can imply different things. I doubt we'll get to a complicated pressurization system, at least anytime soon.

[isoaker]

So we'll start talking about EPS (Elastic Pressure Systems) now? I suppose that makes the most sense. Time to update various terminology on iSoaker.com.

[SSCBen]

I prefer to use common, well-known terms with well-known adjectives to prevent confusion created through unnecessary acronyms.

Rubber CPS is the CPS of the original series, Hydro Power, and latex rubber tubing homemade water guns. Constant air pressure describes a CPS where an air regulator is used. Constant gas pressure is also possible. Spring CPS is just that, a spring-powered CPS system. I've used these terms for a while and I think they're simpler than "EPS" which doesn't necessarily mean a CPS. You could use elastic tubing like a rubber band and get very unconstant pressure. Rubber CPS makes more sense.

[isoaker]

Elastic Pressure is definitely not equal to Constant Pressure. Never stated that. However, the way iSoaker.com sorts soakers, non-constant-pressure soakers like the Splat Blaster are listed under CPSSeries as it uses a spring as opposed to air pressure. As noted earlier, too, the rubber diaphragm system used by BBT isn't quite delivering constant pressure, either. I agree that adding another acronym isn't the best idea. However, I would not want to categorize a constant pressure air-based soaker into the "CPSSeries" section on iSoaker.com. I prefer sorting soakers based on the method of pressurization, not whether they manage to keep pressures constant or not. I, however, would not want to start subdiving things further such as splitting pressurized reservoirs from separate air pressure chambers or dividing the CPSSeries section Hydro Power (rubber diaphragm), Hydro Power (spring), and Rubber CPS. That just gets too messy to track, IMO. Thus, Elastic Pressure System it shall be (at least for here). On the boards, will still mostly use terms like CPS and Hydro Power. Were I to add another Soaker Class to iSoaker.com, I'd consider adding "Motorized" for soakers like the Tarantula and old motorized water guns like the Larami Uzi, but the Scorpion would still fall under Elastic Pressure.