60Hz hose motion?

Hey all!

Trying to create a sine wave with water at a specific frequency, 60Hz or higher, in order to do something similar to this: https://www.youtube.com/watch?v=lpPV05ioAtM

I've thought about using different actuators but none seem to cut it: servo is probably too slow, DC motors I salvaged from an old Xbox controller don't have enough torque to move the hose, a piezo buzzer seems to have too little amplitude...

I'm kind of at loss at how to get that sort of movement in a fairly small package (this is an important requirement), and was hoping that you guys could point me to something I could use?

I have some old laptop speakers that might do the trick, but I'm afraid they won't have enough force to move the hose...

Anyways, any help/ comments are appreciated! Thanks!

I don't think the hose is moving. I think the water stream is flow modulated and the LEDs are synchronized to it to achieve the illusion of movement.

Thanks for the answer!, but I'm not quite sure I follow...

I get that the lighting is synchronized with the water, but to get that shape, the water has to move side to side ? And the only way of really achieving that is to move the hose as the water exits it, no?

Can you explain what you mean with "flow modulated"?

Thanks!

Google "POV display"

flow modulated ~= turned on and off really fast. :)

But... Flow modulation gives an effect like this, no? https://www.youtube.com/watch?v=LqMFiVkvxQw

You need to move the water left/ right to get that sine wave, no amount of turning on or off could move the water sideways? Sorry if I'm being dense, and I get the concept of POV displays and flow modulation, but I don't see how this creates the "shape" in the water (shape frozen by the strobe, but the water has to physically move side to side).

EDIT: Also, if you look at this video https://www.youtube.com/watch?v=x259WW-QEl4, you can clearly see that the hose is moving.

Key to these effects is indeed the LEDs themselves.

The first video in #4 is just a stream of drops and a strobe effect, making them appear to fall upward. The Aquarius thing is a bit more advanced obviously. The Youtube description says it’s open sourced, so it shouldn’t be too hard to recreate. Just check the sources and the build plans (I assume the whole thing is open sourced, not just the code that drives the LEDs).

Are there any direct links to the project, so no guessing is needed?

Just to clarify, I've already built the fountain where the droplets "climb", and yes it's open source.

I also know the theory behind the sine wave which I want to recreate, I just can't find a good way of moving the hose side to side at the desired frequency. That project was made on kickstarter, and is not, to my knowledge, open source.

So really all I need is a way to move the hose side to side at a frequency of 60Hz.

I appreciate all the replies! :)

So really all I need is a way to move the hose side to side at a frequency of 60Hz.

My approach would be to use a motor with an inline crank and slider to generate the reciprocating motion. It may not be a perfect sinusoid, but how close do you need to be?

I don't need a perfect sine wave, juste something that looks roughly like it :) That would work, and I have considered that, but what motor would you use? DC?

The issue with that is the crank-slider is that it needs to be well built to reduce friction... 3D printed with the motors I have now will now work due to the rigidity of the hose and the friction of the mechanism... Guess I'd need to look for different motors then?

Thanks for the idea!

Hi, You would be able to get the nozzle to sweep like that with the nozzle resting against a CAM that is driven by a speed controlled motor.

Tom... :)

cattledog: My approach would be to use a motor with an inline crank and slider to generate the reciprocating motion. It may not be a perfect sinusoid, but how close do you need to be?

My Earth Science teacher made waves using a board with a motor on the back. The motor turned an off-center weight, the board moved back and forth and made waves to show different modes of shoreline erosion on a sand table. That was 71-72.

I am pretty sure there are youtube videos showing the same technique but I don't have the bandwidth to surf there.

Other kind of waves, also cool, https://www.exploratorium.edu/snacks/string-machine

GoForSmoke:
My Earth Science teacher made waves using a board with a motor on the back. The motor turned an off-center weight, the board moved back and forth and made waves to show different modes of shoreline erosion on a sand table. That was 71-72.

Oh yes, the ripple tank with strobe light over head.
That was same time @GoForSmoke.
1398-259x300.jpg

Tom... :slight_smile:

1398-259x300.jpg

You had a strobe? Oh wow! Mr. Mountz did set up blocks for a double-slit. That pattern was very clear. Before that we saw diffusion around points.

Small diameter silicone tubing is quite flexible, much better than plastic tubing. Check hobby supply places for silicon fuel tubing, might also find it in a hardware store for small gasoline engines.

Perhaps instead of moving a hose you could make a nozzle with a motor-driven reciprocating gap/hole?

bobothner: Hey all!

Trying to create a sine wave with water at a specific frequency, 60Hz or higher, in order to do something similar to this: https://www.youtube.com/watch?v=lpPV05ioAtM

That's clearly using a spinning nozzle to generate a helical flow, then using strobe lights to freeze the motion, all mechanical. Probably has a magnet on the spinning nozzle so the electronics can track the spin.

I've thought about using different actuators but none seem to cut it: servo is probably too slow, DC motors I salvaged from an old Xbox controller don't have enough torque to move the hose, a piezo buzzer seems to have too little amplitude...

To do this linearly you'd need a linear motor. Voice-coil actuator is another name. Big, power hungry, expensive. Which is why the Aquarius chose a simple spinning nozzle.

I'm kind of at loss at how to get that sort of movement in a fairly small package (this is an important requirement), and was hoping that you guys could point me to something I could use?

I have some old laptop speakers that might do the trick, but I'm afraid they won't have enough force to move the hose...

Anyways, any help/ comments are appreciated! Thanks!

I too originally thought the hose was spinning, but in this video that the OP posted in an edit to post#4 the hose is clearly translating. Also the water receiver is is linear and not circular.

https://www.youtube.com/watch?v=x259WW-QEl4

How many ways to turn circular motion into linear motion or some other?

This is from 1931. Mechanical Principles. https://www.youtube.com/watch?v=N4WA1gcIJio

But with water if you have a stationary plate with a straight slot cut across the center, another plate could be turned with a curved slot that crosses the straight one so that as the second plate turns its slot crosses the first's to move the hole along the straight slot and back. But.. instead of a slot the second plate has a line of holes and you get droplets.

Maybe with higher rpm you will need bigger holes and a wider slot to not end up with mist.