NEW PROJECT TIME

Thanks Covewi
In studying this, I have two concerns or ideas/questions.
First, my designs nozzle is not like theres, and i'd like to get a more tighter and laminer flow, if that is the right word. I will trial some more tonight and provide some video, but I think mine are no where as household nozzle stream shape... So I am thinking I have to make or find or taper down the current nozzle to something more like theres.

The other is that I have to experiment with pressures. Do you know about what the mini shooter uses for air pressure.

And can we assume they are strickly using air to lift it or thrust it, versus some sort of piston or plunger in front of the air (like i employed)...

Did you see anything in my design that seemed out of place or likely wasn't effective. Thanks again. keep the comments coming.

If you are interested in getting a laminar stream then I think part of the problem is that you are funneling down the output. You want an abrupt stop and to have an exit right there.

John wrote:If you are interested in getting a laminar stream then I think part of the problem is that you are funneling down the output. You want an abrupt stop and to have an exit right there.

So, similar to the WET super shooter, the termination should go right from the 4" Diameter to maybe 1.5". do you think i could take a 4" pvc cap and just drill a 1.5" hole in it and get the stream more laminar?

That's my thoughts. You want it to come to a flat stop, no reduction or anything. Then you also want to have an exit orifice that have a really sharp edge to it, so you would want it to have a countersink shape to it.

Water flowing through a pipe will have drag on the sides and thus the edges will be moving slower than the center. The idea of the straws it to have all the water moving in the same direction and at the same speed. But if you constrain it to move as a block, as with the plunger, then will there be drag on the walls so that it isn't moving all at the same speed?

I have some concern with the plunger in that you must make sure it can always fall back down during reloading and there should be some sort of "stopper" at the top of the nozzle to
prevent repetitive micro trauma of the plunger hitting the taper of your nozzle which may weaken the nozzle, get stuck or fail to fall back down.

The next item to be addressed would be how to refill the tank without "dunking" it. It could sit in a body of water (fountain, pool etc) and allow it to passively fill from the bottom up - which would self level with the depth of the surrounding water. If this method were used you would have to have a check valve in the water inlet to prevent the air from being shot out the water inlet.

One of Wet Designs patents talks about the different exit nozzle possibilities. They do mention the use of a laminar "brass" nozzle which would help give a clean compact stream of water.

Of course all of our "own" projects will be different depending on the needs or desired effect. I got away from the "barrel" nozzle that you are using and went with a rounded pvc cap with a 1/2 inch counter sunk hole. It appears to give "tube" of water that stays together nicely.

I found that using the "barrel" nozzle (with too many psi"s) allowed the compressed air to start moving faster than the exiting water which created a circular explosion of water (around the nozzle tip) sometimes being 2-3 feet in diameter. So a lot of the water was "wasted" and not shot up.

I need video.

i have a small hole in the plunger, and I feel the water acts as a cushion. There seems to not be any real hard hit at the end of the cycle.
i intend to fill it with a hose so dunking and the related valveing is not necessary.
I have nozzled it down to a 1.25" and it became a bit better.
I've shot it at 80 psi with good results.
I need to inquire about the counter sunk hole. which end or side of the cap is the wider or narrower side. I suspect the narrow side would be on the water side...
I was wondering about glueing three 1/2 sch 80 pvc pipes down the 2" secondary barrel to try to "train" the laminar flow just before it exits a likely 1.25" hole, that is if I drill a new counter sunk hole in a new 2" cap. I will try to get video tomorrow morning. I am impressed with this thing, but there is no way someone can "hold" this and shoot as one its heavy and two, the kick is serious.
an interesting note, the 9 volt battery would trigger the solonoid ok with 40 pounds of pressure on the valve, but with 80, it was dead. adding another battery fixed it. Yes, I know the solonoid is 24 volts, but...
thanks guys.

I posted a video of two shots on YouTube. about 70 psi. It is hard to see the whole stream in the video, but it's pretty close to the length of a tennis court, so maybe 120 feet vertical.

Water Cannon video on YouTube

Enjoy. Comments welcome

That looks great and at 70psi you are getting plenty of height! Are you using this in your pool? You mentioned that you have a plunger or something to push the water out? Have you tried it without the plunger?

John wrote:That looks great and at 70psi you are getting plenty of height! Are you using this in your pool? You mentioned that you have a plunger or something to push the water out? Have you tried it without the plunger?

No, I would like to but the reducer fitting is glued on, and I seem ok with the results. Would like to hear from someone that they think it could get better without a plunger.

In about an hour or so the same video in a clearer view will be on Vimeo.

Same video on Vimeo

Looks fantastic = what are your ultimate plans for this monster cannon?

Check out

www.sscentral.org - they have a great deal of information about the type of project your building - great builds, physics and tech stuff.

covewi wrote:Looks fantastic = what are your ultimate plans for this monster cannon?

Check out

www.sscentral.org - they have a great deal of information about the type of project your building - great builds, physics and tech stuff.

ultimately I wanted something I could take on the lake boat and soak my friends boat, from an impressive distance. I sort of forgot about the "kick" so I'll have to wedge the butt against something besides my thigh, like the gunnel in the boat. I'll bring it this weekend. Covewi, what are your suspicions about the plunger employment versus straight air blast push?

Just found this -

http://www.google.com/patents?id=Gd0YAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

No real concern - sounds like the plunger is actually a better idea - since some of the concerns are that the high pressure air can shoot through the center of
the water and actually exit without expelling water.

The plunge appears to solve that problem - Wet Designs mini shooter is 5 feet tall and shoots around 125 feet. You have accomplished that in a smaller more
compact design. I like it.

I am looking to make more of a water display with multiple shooters ranging from 10 - 30 feet. You need to make some sort of mounting device on wheels - like a cannon would have.

covewi wrote:Pbracer - you will need to pressurize the air tube to significantly expel the amount water in a 4 " inch diameter tube - enough to produce a "large" air bubble.

With you set up - the volume of compressed air should just about equal the volume of water your trying to shoot - I got that info from several Wet Design videos I have seen.

I am uncertain how to form an air bubble when the air is already above the water and pushing down on it? I guess it is possible to form a bubble if the air is released into the chamber in a narrow jet as opposed to a blast. If a certain amount of air was left at the top in the angled chamber then no bubble should form regardless of the air nozzle type used to "fill" the chamber.
And I agree that the volume of uncompressed air equal to the volume of water to be displaced, is what is required to displace the water. It is the "uncompressing" of that air in the down direction on the one side that drives the water up the other side and out the nozzle.
This is the simplicity of the Wet patent, and the reason they require no plunger that might foul, get stuck, or not "return" fast enough. The beauty of this design is in its simplicity and the lack of parts, especially moving parts, that are required to make it work.

I may have posted this before but it gives a good idea of what the shooters are doing. It may be a reference point for your project.

Innoventions Fountain Facts

* 212 Micro Shooters® located in the upper pool; each propels 2 gallons of water up to 80 feet in the air.

* 40 MiniShooters® located in the lower pool; each propels 5 gallons of water up to 100 feet in the air.

* 12 SuperShooters® located in the upper pool; each propels 50 gallons of water up to 150 feet in the air.

* 60 Spray nozzles

* Air accumulators for the SuperShooters® activates with pressures of 30 PSI to 120 PSI.

* 190,000 feet (35 miles) of electrical wire and 22,000 feet (4 miles) of conduit.

* If all of the shooters triggered simultaneously, there would be 2,000 gallons of water in the air.

Note that Shooter®, MicroShooter®, MiniShooter®, SuperShooter® are registered trademarks of WET Design.