Has anyone here made a CPS with an electric pump?

[theTman1221]

I was just wondering if anyone here has made a CPS style water gun using an electric pump. I have thought about using a rechargeable NiMH battery pack for power as I have dealt with them a lot when I was into RC cars. I think it would be possible for a pump powered from such a pack to pump up a bladder if it has enough torque. It may be a little on the slow side though. I'm going to dig around to see what I can find for DC water pumps.

I'm new to the forum and have never built a gun, but have been doing research and I am an engineering student with a knack for this sort of thing. My basic idea is a water reservoir with an electric pump pushing water through a check valve and into a bladder made of layered balloons, and then maybe use an electric sprinkler valve for the trigger (I've seen them work wonders for air cannon triggers) Naturally this would require proper waterproofing, but if I can make a submersible rock crawling RC car this should be easy lol!

Hopefully someone has tried this and can offer advice, but in the meantime I'll be looking around to see if I can find a suitable pump.

[theTman1221]

Update: I looked around online, and while I found many DC mini water pumps, most did not list pressure tolerance. On Ebay there was a series of submersible water pumps that could handle 70 psi and draw around 850mah (that means you could run the pump for a few hours on a good NIMH battery pack). A lot more research is required, but this may be a possibility.

[DX]

Most people here are pretty competitive and prefer to pump our soakers. Our community wars aren't ideal places for electrical components, so they are rarely fielded. Electric tends to be laggy, lacking the precise control and usually the speed of manual pumping. It also tends to be louder, which could give away your position. Waterproofing is always a concern, but it looks like you know where to look on that subject. You also need to carry multiple battery packs, unless it's a casual war near a power source to recharge them. 4 hours off the grid is actually not enough to last through a community war. I have trouble just getting my "gun cam" charged during these wars.

Latex rubber tubing (LRT) will be a better bet than a balloon PC, as it's difficult to start layering the balloons. It's easy for K-mods, since there is the stock bladder to layer on. You'd need to find something to layer them on and then be able to remove it. Balloon PCs are poorly documented, so that will likely be trial and error. LRT is readily available on McMaster-Carr and is well documented.

A sprinkler valve will only be good in a large enough size, otherwise it's a bottleneck. The size of the tubing between the PC(s) and nozzle makes a big difference for the overall power potential. I never go smaller than 3/4" ball valves. The full flow of a ball valve is awesome and straight, with no turns. Air guns are not a great source for water gun knowledge, because shooting water is quite unlike shooting solid projectiles. A fast valve in a water gun will introduce turbulence in the stream and can hurt the shot time. Many XPs and PR guns intentionally have slow air releases in order to increase the shot time. Water is a pretty finicky projectile and the slightest problem can wreck its performance.

I would definitely recommend building a CPH with a manual pump first to see how it works and what its quirks are, then designing your electric-powered version around the results (which could be done by just changing the pump and reservoir, you don't need to build 2 models).

[marauder]

I encourage you to try out your idea. Not because I think electric pumps would be that tactical, but because I might be wrong, and even if I'm not you'll still learn something in the process - and maybe the rest of us will too. Good luck.

[theTman1221]

I think I may have miscalculated in converting the pressure units on the rating of the previously mentioned pump, and on top of that I never saved the link and can't find it lol! Further searching has shown that a pump that can put out the needed psi is big, heavy, expensive, and needs a very large battery. I guess manual pumping might be better. I had seen some designs for a gun powered by compressed air that is pre-charged, but I'm skeptical of it's viability for a water war due to needing to be pressurized by an external source.

[marauder]

I have considered using an air compressor for powering waterballoon launchers simply because it would auto charge for me while I was using or carrying an actual watergun. That way it would be ready for me whenever I needed to switch to it. Of course, you'd have to have some way for it to shut off automatically at a certain PSI. I considered mounting the battery below the gun in a magazine/clip like attachment.

[theTman1221]

I wonder if it would be a good idea to make a flexible bladder inside a sealed chamber filled with air, and filling the bladder would compress the air. I would need to have an pipe end cap that I can put a pipe through to attach the inner bladder but still maintain a seal. The advantage of this is not dealing with rubber wearing out from constant stretching and the ability to alter the power via a tire stem type valve on the pressure tank.


Edit: oh wait, I just realized that you wouldn't get constant pressure with such a setup.

[the oncoming storm]

The only person on here who made an self pumping CPS blaster was Big Bee and the Water Warriors Scorpion

[isoaker]

As "the oncoming storm" already noted, while I don't think anyone has made one of these at home, the Water Warriors Scorpion was a motorized CPS-system that worked very well. It used a rechargeable Ni-Cad battery, but I'm not sure what sort of motor it used. It did have a sensor to shut off the pump once the PC was filled, though I could also imaging using a physical switch that could be used to turn off the motor/pump once the PC had expanded to a certain size.

[marauder]

Doesn't someone on here have a Scorpion? Wasn't it supposedly underpowered? Not sure if that has anything to do with the electric motor or not.

[the oncoming storm]

It's more powerful than XP class blasters

[isoaker]

Doesn't someone on here have a Scorpion? Wasn't it supposedly underpowered? Not sure if that has anything to do with the electric motor or not.

Oddly, I don't have range measurements, but while the Scorpion didn't have quite the sting of a CPS 1000 on its largest setting, it definitely could outperform perhaps all but the SS300 with its diaphragm-based motor-pumped system.

[marauder]

That's pretty cool. I never remember seeing them in stores.

[soakinader]

Hey, if the scorpion could do it, so can you. Don't give up so easily, I believe it is highly possible. The Scorpion is like the proof of concept. It's simply a matter of finding a pump with the combination of small size/weight, small pump stroke, and enough power to fill up an LRT pressure chamber.

[SEAL]

Well hey, some of us like pumping, for the same reason that we prefer manual transmissions over automatics.

In all seriousness, the only reason to opt for an electric pump would be if it's faster than a regular pump. I don't think it'd present much of a problem though, especially for CPS. Like soakinader said, you just have to find the right pump (or you could try your hand at making one).

I'm an engineering student too, by the way.

[Andrew]

I'm another one who prefers manual pumping. Best of both worlds would be an electric pump, with manual override/bypass.

In all seriousness, the only reason to opt for an electric pump would be if it's faster than a regular pump.

Dual wielding? If you put make the pump automatic (pump whenever the PC is less than full) or put the controls within reach of the firing hand (second trigger?) it could work.

Another engineer here aswell, well in four years time officially.

[the oncoming storm]

I would love an electric pump on a water gun, pumping hinders aiming and your arm can wear out quickly if your pumping a 2000 or 300 in a raging firefight.

[Nemesis]

Pumping manually also tones your arm!