[neils]

It seems so easy, yet it is not working for me. Using compressed air to a valve. Now, I tried 2 different methods, both do not work.

1) Use a Tee to combine water line and air line with hopes to get a spray. Instead, the TEE is pushing air down the water line into the water container, making the water bubble. No gravity or pull to get the water to flow the other way naturally.

2) The more sophisticated way, I poked 2 holes in a container, 1 air line into the container to pressurize it (making the water bubble at all times), and one line coming out of the container. While I don't love the pressurized container idea and water bubbling all the time, it kinda works, as I get a very weak stream of water coming out of the output line. So then I figured, split the air line, so it feeds the container to pressurize it, and allow the air to continue to mix with the output of the pressurized container, so that the weak steam of water coming out can then mix with pressurized air to get that spitting effect.

Nope, instead, it seems like the air mix is still forcing it's way back into the output line too, stopping water from coming into the main feed.

I would like to avoid building the weaker setup of sticking a small tube onto a larger air tube at the end, creating a mist. I want something a little more powerful and elaborate. My home haunt runs off of a 60 gallon continuous duty compressor, so no worries about air.

Any ideas what I am doing wrong ?? I even purchased the water tips from Fright Props, the ones that pressure fit onto the tube, but until I can get the system working and water feeding properly, I cannot even attempt to use those tips to tighten the water pattern.

Thanks
Neil

 

[neils]

FrightProps actually has a DIY write up on this.http://blog.frightprops.com/how-to-make-a-diy-water-mister/

Yup, thanks, seen that video, while that setup will probably work (hopefully for me), I am trying to keep that one as a last resort. Rather than build what they sell as an affordable average "mister", I want to replicate their more elaborate sprayer system, the one that uses their pressure fitted water tips. As you probably saw in their comparison video, their full blown pneumatic and electric pump systems puts out way more water (volume and distance) compared to the cheaper one from the video.

So hopefully someone can explain to me why the air is blowing back down into the water line and container, instead of siphoning the water with the air pressure instead.

Basically trying to build this with Tee and Y adapters using a solenoid valve.
http://www.frightprops.com/props/air-electric-props/water-sprayers/spray-system-pneumatic-25389.html


Thanks
Neil

 

[neils]

Ah, so are you telling me that inside of that black bucket of theirs sits some sort of pneumatic pump ?? Meaning, once air is fed into that bucket from a valve, it somehow pushes water thru a pneumatic pump, and out of another hose, with a strong stream of water ??

If so, that would explain why I cannot replicate it with simple air pressure fittings, I thought it was simply a matter of pressurizing a water bucket filled with water, and out would come a strong stream that I could then mix with air. But of course the air forces it's way back down the water hose into the bucket.

FrightProps wrote back to me to say they use some sort of combination of 2 cylinders and check valves inside their pneumatic bucket system, but trying to understand what kind of cylinders they are talking about, can't be air cylinders moving back and forth in there can it ?? Didn't think you could submerge cylinders, and even if you could, how would a moving cylinder create water pressure.

Guess I have to study this further....

 

[neils]

Yeah, all makes sense now, this is going to be a matter of trying to source what they call a pneumatic displacement pump, which is pretty much a cylinder with a piston inside and a couple of built-in check valves. When air is applied on one side, one check valve open up and the movement of the internal piston will pull in the water to fill the cylinder. When the air valve is triggered, the piston moves in the other direction, essentially closing the 1st check valve where water is pulled in, and the 2nd check valve opens to push the water in the cylinder out. Now how fast the piston moves and what does that water pressure look like is a whole other story, but I guess since FrightProps does it this way, must be fantastic.

I just have to figure out now where the heck to buy a displacement cylinder small enough to fit inside of a bucket to displace water and create my Halloween sprayer.

If it gets too complex, I guess my other option, besides building that DIY version, is to source an electric submersible pump, and hope the pressure is enough to give me a good spray. Anyone play with electric submersible pumps ?? Does it still have to be combined with air to get a better spray ?

Neil

 

[neils]

Not a bad idea J-Man, will try out the venturi method tomorrow and see how much water comes out. I have a sophisticated trigger setup, can trigger multiple things at the same time. Can use a 12v transformer for the windshield washer pump on the same circuit as the valve. At least I got a couple of options now, but I am still curious to hunt down one of these submersible pneumatic displacement pumps/cylinders.

 

[neils]

Mr Captain Hook, you have solved the mystery, along with J-Man that hinted about a pump being used inside the barrel. After speaking with the FrightProps folks, they mentioned something about using "a couple of cylinders" in their pneumatic system but I did not make the connection that they were talking about air cylinders,because I did not think air cylinders could be submerged in water. So that is exactly how they do it, one air cylinder moves back and forth with the valve, with the first cylinder moving the 2nd cylinder, and the 2nd cylinder is the one that acts as the water displacement cylinder, with installed check valves.

The couple of limitations I see, first one has to source very short cylinders, such that 2 joined together can fit inside of a decent size bucket, probably standing up. Second, the water level cannot drop below the water intake port of the cylinder, which would be the lowest one in the bucket. Hopefully it is the lower port that will take in the water when standing, and not the upper most port.

Either way, you gave me some more info to work with. Was just about to place an order with FrightProps, might order a bunch of short cylinders to try this all out.

The million dollar question now, what length of cylinder. Too short and you don't have enough water to push thru the tube, too long and you might have too much water and the whole setup might not fit inside of the bucket.

Any best guesses, assuming this all fits inside a 5 gallon bucket with maybe a 10\ water hose length ??

Thanks guys, really appreciate this info !!

Neil

 

[neils]

Thanks for the feedback J-Man, I guess you are right about not having to submerge the cylinders, I keep looking at the finished product from FrightProps, and assumed they had 2 cylinders joined together with a coupler that had to fit inside of the 14" tall 5-gallon bucket. If that was the case, the longest cylinder that could be used would be a 4" (1-extended @ 8", 1-retracted @ 4", 1-2" coupler). But if the whole rig sat outside the bucket, then one could design whatever length they needed and mount the cylinders solidly to some wood.

I am not sure you suggested a Y though. Two hoses would run from the air valve to the double-action cylinder, which is the one coupled and driving the 2nd water cylinder. For the double-action water cylinder, you just need a check valve and line into the water bucket feeding one side, and then another line with check valve from the cylinder to the spitter. Perhaps you can explain your thoughts about why to combine 2 lines with a Y, unless you assumed I was using a single-action cyclinder instead of a double-action.

Also trying to figure out if I should go with an inline setup for both cylinders and a coupler, or if I should try to mount the 2 cylinders side-by-side, and figure out a way to join the 2 clevis with a long enough clevis pin so both cylinders move without too much tension. My guess is the inline setup would work best.

Also trying to figure out the ideal length of cylinder, need it long enough to be able pump a decent amount of water thru the line to the spitter without it being too much. I was thinking a 4" or 5", but that might be too short.

Neil

 

[neils]

All worked out guys, and yes J-Man, you are correct. Dumb dumb realized this when I was waiting for water to blast out the other end of the cylinder, and it never happened. That is when your comment about the Y came to mind, and I understood what you meant. Since I had a pair of double acting cylinders lying around, I decided to bolt them onto a piece of 2X4, facing each other, and I interlocked the clevis mounts. Tried it out and worked like a charm. Of course these are 12" cylinders, a lot longer than the 4"-5" ones I was initially planning on ordering for the project.

Of course to really make this whole thing work properly, you really need those pressure fit water tips from FrightProps, else you get a very strong stream of water that would soak whoever is underneath it, and the spray tip also creates a nicer spray that distributes much better.

I was so impressed with how the whole setup works, that I might have to make a YouTube video to help others build this thing. FrightProps sells the system for $250, all you need is 2 cylinders, 2 clevis, 2 rear mounts, 2 check valves, and a solenoid valve. Of course a nice big bucket of water as well. One cylinder pushes the other, one uses air while the other moves the water. Brilliant.

Since my Halloween Haunt is already setup, I tried it out with my photoelectric sensors, and walking by it triggered the valve, and got a nice spray of water. There is so much going on in that area, with animatronic props, music, flashing lights, that the water will catch people off guard when standing around to look at all that stuff.

Thanks again guys for all the guidance, your hints along the way made me resalize what parts I had to slap together. Incredible community here !

Neil

 

[neils]

I hear you J-Man, I made my wife walk under it, as well as a few kids, and I mostly got screams and laughs, so I don't think it is as bad as I made it sound above. For sure it is not a light mist like the cheaper DIY design where you snap one hose into another (venturi). I think having the spray tip helps diffuse the quantity of water. The next thing I will probably do is replace the 12" cyclinders with 8" ones, to see if I can lessen the water duration a bit, so basically a shorter blast of water from a smaller cylinder.

If you look at the barrel type pneumatic prop spitters from Distrortions, it's about a spray like that. I also have a post timer on the trigger, so I might add some delay time such that I am not getting everyone in line.

Thanks again !!