Jumping Water Flumes

Next spring I plan to build my version of the Jumping Water.
I think I have everything that I need to do this (plc's are
Modicon 984 A130 w/2k mem and SLC 5-01 w/1k mem).
There are going to be three towers aranged in a triangular
form with water jumping back and forth and crashing.

My question is, what function blocks do I need to learn to do
this? I can do timmers, counters, compares, and drums (can more
than 1 drum be in a program using the same outputs?)

Hopfully someone here has done this kind of project and would
just help me get the grey matter going.

Just as note I recently changed jobs. Johnson Controls, Cadiz, Ky.
in Maintenance. They are looking for more too, Just pass the test.
Lots and lots and lots of welding robots (Panisonic and MotoMan).

Are you referring to the display at Detroit Metro Airport. That is an awewsome display and the timing seems to change on the display all the time.

No the one I saw was at the Epcot center at Florida over
ten years ago.
And since I finally got enough stuff toghether, I'm
gonna give it a go.

Hopefully this one will have colored lights that will
come on shortly after an assigned gun fires. Maybe
even interface an HMI to control/monitor it. And even
have some secret guns to get someone wet when opted by
an opto touch (that'll get them button pushers).

I would suggest some type of pinchart & sequence format for your program.

STEP 1: 010100101010100101
STEP 2: 101010010011111100
STEP 3: 111111111111111111

and just use plc's internal sequencer command or build your own sequencer to load the step into output. You can step through using one timer with timer's preset as a indexed file, ie TIMERPRESET:[STEP#]

STEP 1: 5 (SECONDS)
STEP 2: 3
STEP 3: 5

and so on...

This format make it easy to change your display once the base sequence is built.

Have Fun.

HT

WOW !!! What a kick in the A$$!!!

What method are you using to make the water-slug coherent?

I've wanted to do one of those for a long time.

As far as timing, between hop-to-hop, it's a basic trajectory game; force (pressure), mass of the slug, velocity, gravity, angle.

It has occurred to me that being coherent might introduce a "mass" problem. A slug traveling as a single-mass might be a little different from a mass of coherent masses.

Terry Woods said:

What method are you using to make the water-slug coherent?

Click to expand...

I'd be interested in knowing this as well!... I have stared in awe at the ones at Epcot... Mostly at how precisly the entering and exiting water was timed. It looked as if it were the same "slug" of water! Too cool!...

A neat way to approach this timing issue might be to sense the leading and trailing edge of the water slug as it entered the next "hop" station. Then use this info to start and stop the outgoing slug. The benefit of this would be that each station would now be "smart". Let's say someone "intercepts" the slug's progression... The receiving station would "know", and not fire off another slug. Or maybe fire at the offending party?... lolis

Additionally, if you sense the incoming slug, you don't have to worry about constantly adjusting the timing due to variations in pressure, etc... Now, how to sense the incoming slug reliably?...

Excellent project idea!... Why wait 'til spring? C'mon Caveman, I thought it was always a constant 52°F in a cave?...

beerchug

-Eric

Let's say someone "intercepts" the slug's progression... The receiving station would "know", and not fire off another slug. Or maybe fire at the offending party?... lolis

That is one of my thoughts too. And yes the towers will have sensors
to know when it catches the slug. There are a lot of possibilitys
with about 30-1/4" solinoid valves and a full box of about any sensor
you could imagine.

Terry Woods said:

It has occurred to me that being coherent might introduce a "mass" problem. A slug traveling as a single-mass might be a little different from a mass of coherent masses.

Click to expand...

Mass has nothing to do with it (barring air resistance, of course).

Physics 101, 2nd week:

<center>Eq. 1    X = X<sub>0</sub> + v<sub>Xo</sub>t + ½a<sub>x</sub>t<sup>2</sup> </center>



<center>Eq. 2    v<sub>Y</sub> = v<sub>Yo</sub> + a<sub>y</sub>t</center>



<center>Eq. 3    v<sub>Xo</sub> = v<sub>o</sub> sin(Ø)</center>



<center>Eq. 4    v<sub>Yo</sub> = v<sub>o</sub> cos(Ø)</center>

.
Combine Equations 2 and 4, use 'g' (-9.8 m/sec²) for 'a', and the fact that v_Y = 0 when the 'object' (slug, bullet, ping-pong ball) is at the peak to calculate time, t, that the object will remain in the air.

Substitute t into a combination of Equations 1 and 3 to calculate the distance the object will travel.

As long as the muzzle velocity (v_o) remains constant, the slug will stay cohesive (because all the parts will travel the same distance.

The real trick is to have the muzzle velocity go from zero to v_o , and from v_o to zero as fast as possible. Perhaps blocking any water that isn't travelling at v_o (i.e., establish flow first, then quickly divert the flow to the air, rather than trying to get instant accelleration.

Personal Historical Note: My dad was the operator for the Dancing Waters some 40 years ago. Everything (then) was pneumatically controlled and the sequencing was done by hand. I think I need to have a talk with him about some of that stuff....

Great project. When you get it working, post an AVI file. I'd love to see it in action.

These guys http://www.atlanticfountains.com/ make fountains for all kinds of applications. They have some cool equipment, but it costs some bucks. But maybe you can get some ideas from the site. What they call "laminar jets" are what I think you are talking about wanting. It's kind of the glass rod look....very cool.

Personal Historical Note: My dad was the operator for the Dancing Waters some 40 years ago. Everything (then) was pneumatically controlled and the sequencing was done by hand. I think I need to have a talk with him about some of that stuff....

Click to expand...

Absolutely fascinating stuff! Great Website! (Dancing Waters) I will enjoy reading this thread. I hope we can come to some revealing insights.
Kewl!

How to make Coherent Water (CW-101)

Go to McDonalds and grab a handful of their skinny straws. Bundle them together.

That's your wave-guide. The smaller the straws, the more coherent the water is when it comes out. The object is to minimize turbulance between molecules. The ideal would be a stream of water molecules goose-stepping, nuts-to-butts, across the sky.

Of course, the smaller the straws, the more pressure it takes to push the slug through the inherent resistance in the straws. There's a reasonable balance between straw size and pressure in there somewhere. After all, you're just looking for the effect... not coherent perfection!

I think a pneumatic accumulator, with a large dump valve, is the only way to go.

As far as sensing the arrival of a slug... consider an acoustical sensor. Or, if the slug hits a target, mount the target so it is balanced without water. Then put a tip-switch on the target.

BTW, you'll get the greatest distance by firing at 45-degrees.


Allen said...
Mass has nothing to do with it (barring air resistance, of course).

I wasn't talking about mass as in weight, but rather mass as in structure. Hence, "Mass" in quotes, as in structure... next time, I'll say structure.

You were close when you said "barring air resistance". But the real "air-issue" I was referring to was the aerodynamics of the single-mass vs. the aerodynamics of the mass of single masses.

That is why I specified a difference between a single-mass and a mass of coherent masses. You can throw a block of styrofoam pretty good... but, you can't throw a handful of those styrofoam peanuts from here to there to save your life.

If the streams are so coherent as to remain separated to some degree, you might actually get air currents in-between the coherent streams. It might actually tend to glide! At least, the outer streams might tend to peel away.

Hell, I don't know! I haven't built one.... yet!

Hopefully tonight I'll get to get a few different sizes
of nipples and mill or cut a tiny lenghtwise slot and
then insert a strip of stainless steel then weld the
slit back up. Next time you drink from a fountain look
at the nozzle and you'll see what I'm talking about.

If more coherence is needed maybe add a filter as the
site Glaverty linked to did.

Paralleling 2 valves is not out of the question.
1 gallon accumulators in each tower to allow for pressure
drop when more than 1 gun fires.

I'm also hoping to recycle the water.

Interesting note about "slug-making"... It seems that they don't turn the laminar stream on and off, but rather inhibit the flow with a secondary "curtain" of water. Here's a clip from the Exclusive Fountains page:

"...the water is a continuous flow, but to stop it coming from the outlet end a second supply of water is forced across the main flow at considerable pressure. (a bit like the "lance" on a pressure washer) stopping it from leaving the main tube. This second flow of water is controlled by a valve. So by controlling the rate of the second water flow you can "cut" the flow of water to create a "glass like rod" of any length you require. Which is called the laminar jet"

And according to this clip from Hidden Mickeys, that's how Epcot does it:

(Side note: Hidden Mickeys is a cool site!)

"The short tubes at Epcot are created by cutting the main laminar stream with a secondary water supply with a small nozzle on it. The nozzle is similar to one that you would find on the end of a wand at the local car wash. When you want the jet to jump, the separate supply is turned on via a solenoid valve running at higher pressure than the jet supply. You may need a booster pump to get the pressure up. The nozzle is aimed at the exit point of the jet on top of the nozzle housing and when it comes on it diverts the main stream down or away from the desired trajectory. When you want the nozzle to jump you turn the cutter jet off and on quickly and you end up with what ever length tubes you want"


Maybe Allen can confirm this with his dad?...

beerchug

-Eric

Humm... After looking through the vendor's web site it appears the only way to do it "RIGHT", i.e. use another water jet to divert the flow of the "laminar" jet cost BIG $$$$. Otherwise you can just use the cheaper alternative such as a solenoid valve but the jet dont' look as nice (from the video on the web site). I got another idea, how about a 3-way divert valve instead of a open-close valve?? I bet it's cheaper than the secondar water jet deal. You can make one up by using two open-close solenoids, which are cheap(er).

Just my 2 cent.

HT