Water drop equipment

[clarnibass]

Hi

Does anyone here take photos of water drops?

Asking for a friend. She is looking for a method to have water drops dropping at a pretty consistent speed that she can control/change. It's actually not for photography (for now, I might use it for photography later) but somewhat similar needs.

What she doesn't need is the many features and precision of water drop controllers used for photography so she is trying to avoid paying much more than she needs to.

A manual valve that is possible to open/close to control the speed is good enough. It doesn't even have to be remotely.

She has tried IV sets and the control (change between speeds) is too "coarse", moving too fast between very slow and very fast.

Thanks!

[Chris S.]

I don't take pictures of water drops, so it's likely that other members of this forum are better informed than I.

But I did recently alter my house's reverse-osmosis drinking water system. One of the components I used might work here, and is cheap enough that trying it doesn't risk much: a brass needle valve for 1/4" tubing.

While not exactly what I used (I bought my supplies from the local hardware store), this item for under $7 USD is similar. These valves can have inputs and outputs that are threaded, compression fitted, or a combination.

--Chris S.

[Antal]

A bit more expensive solution, but will work out of the box: https://www.cognisys-inc.com/store/water-drops.html
You will also find some information for the set-up on the cognisys page..

[lothman]

Peter Lin offers kits, http://www.mjkzz.com/product-page/three ... r-drop-kit

he is active in this forum as "mjkzz".

[JKT]

Stupid question: Water dropping at consistant speed or at consistant frequency? Likely the latter as former would be simply a matter of dropping distance.

[rolsen]

Interesting, I did very well with IV sets, easy to use and I got them free from the hospital.

[chuong nguyen]

Please take a look at this: https://plutotrigger.com/products/droplet-valve . Reasonable price.

[DaveinMpls]

[quote="chuong nguyen"]Please take a look at this: [url]https://plutotrigger.com/products/droplet-valve[/url] . Reasonable price.[/quote]

This does look very affordable.

But IV tubing works well also. Put on a needle to determine drop size (larger numerical gauge gives smaller drops and increased resistance in the system). Vary the height of the IV bag to reduce the droplet rate (frequency) to as low as zero.

Best, Dave

[clarnibass]

Thanks everyone. She is at the testing stage, so any of the real controllers are too expensive right now.

We'll definitely try the needle valve like the one that Chris S. showed.

Yes I guess I meant frequency, it was bad translation. I meant BPM... or in this case DPM (drops per minute).

The problem with the IV sets (she got dozens of them to try) is only that a tiny movement of the wheel changed the frequency (DPM) too much. One options was to 3D print only that mechanism and make it more "fine adjust", and attach to the IV.

It's not very specific yet, but she generally needs about 3-6 DPM to about 80 DPM but this is a rough idea for now and also depends on what's available.

The height is not completely possible to control either and depends on the ceiling height, but the speed (volume) isn't critical (it's all amplified and can increase gain a little).

Eventually (if the project gets the budget) she might go with something like the MJKZZ controller. I got my macro rail from him so it's the first place I looked.

[Chris S.]

But IV tubing works well also. . . . Vary the height of the IV bag to reduce the droplet rate (frequency) to as low as zero.

The problem with the IV sets (she got dozens of them to try) is only that a tiny movement of the wheel changed the frequency (DPM) too much. . . .

The height is not completely possible to control either and depends on the ceiling height. . . .

So Dave is explaining that drop frequency can be adjusted by changing the height of the IV bag (which makes sense, assuming that the valve remains at stationary height below).

For an easy to adjustably set the height of the bag--regardless of ceiling height: Hang the bag from a rope and tie a taut line hitch to adjust the height of the bag. A taut line hitch is knot that ties one rope to another (or in this case, the end of the same rope to somewhere else on itself. When squeezed, a taut line hitch easily slides wherever you want it on the rope; let go of the taut line hitch, and it holds in place. I've used taut line hitches for tying down cargoes (another name for it is "trucker's hitch"), tying rain flies to tent pegs, and countless other jobs. On Youtube, there are many short tutorials that teach tying this easy knot.

Another knot that would do it--also easy to learn--is the Prusik knot.

--Chris S.

[DaveinMpls]

For those of you who like to photograph rebounding droplets, here is a newly posted video where the droplets literally spin:

https://www.youtube.com/watch?v=3xTcMtdE8z4

Cheers, Dave

[clarnibass]

So Dave is explaining that drop frequency can be adjusted by changing the height of the IV bag (which makes sense, assuming that the valve remains at stationary height below).

I didn't exactly understand that. Why would changing the height of the bag change the frequency? Probably won't be possible in this case but still would like to understand the idea.

[DaveinMpls]

Why would changing the height of the bag change the frequency?

The pressure at the needle tip is governed by the height of the hydrostatic fluid column. Raising the bag increases the pressure, and rate of flow, which translates to more drops per minute. Lower the bag enough and the flow ceases. Try it with an IV bag for yourself.

Best, Dave