Parts for Science Exhibit, WaterDrop machine

[Tinker12]

I was able to design and print parts for a science exhibit I've been working on. I used to make them from polyproplene
and hand cut and machine them, now the magic of Orion 3d printing has made it easy to make nice parts with little effort
on my part compared to before.

here are some photos of the WaterDrop machine and a video of it in action

https://www.dropbox.com/sc/jyhyyjpgtwi4 ... _arCmJuVka

http://youtu.be/TNitk7Qf-7o

[Jimustanguitar]

That's a cool machine! Nice work.

You ought to write out how you made it for instructables or hackaday and share the files. A lot of people would enjoy it!

[DavidF]

That's very cool to watch. My boss came in while I was watching it and asked
"what's that?". My reply was. I'm receiving instructions....LOL

What would it be like if you.colored the water and droplets different colors?

[Tinker12]

"My reply was. I'm receiving instructions..." was that in Beam me up? LOL

I've not tried different colors but might look good with colored water and milk. The waterdrop machine has a recirculating pump to a top reservior for constant pressure feed to the drip nozzle.
The water is dyed with a UV fluorescent dye so it glows when hit by the UV LED strobe lights, this give better visibility than plain or colored water.

[DavidF]

Theeyyrrreeee heeeerreeeeee........
I think it would be interesting to see it in two different colors so you can see how the two mix/ disperse when the droplet impacts. I assume it takes a very special camera to record at that speed??

[Gr8Scott]

From what I saw in that video, it seems like there is a strobe timed to close to the same rate as the droplets that are coming down and the machine simply illuminates each droplet as it makes it's way to the water at the same progression, which appears to stop/reverse or slow time depending on the frequency of the strobe versus the droplets being issued. Am I right or is it stop motion photography of a single droplet?

[jdurand]

From what I've seen, it's a combination. The strobe fires slightly later for each flash and the camera shutter is synchronized to the strobe.

VERY fast shutters can also be used with no strobe, for example you can see a pulse of light appear to slowly travel through a bottle of water. Of course it's many pulses with the shutter opening a very very tiny bit later each time.

I designed a laser controller that had to fire 8 lasers at precisely calibrated differences in time for something like this (only with a very large budget). The front panel controls let you set the 8 outputs from 0 to 1 millisecond offset in 250 picosecond steps.

[Tinker12]

There is a infrared optical sensor in the water drop stream. When an individual water drop breaks the beam the controller board generates a delay, when that expires the UV strobe fires, illuminating the water drop. the delay is adjustable thus you can view the drop at various times in the event. Viewing it live the drop appears to be a single drop at higher frequencies because of persistance of vision effect. The controller board also allows the strobe to fire in single shot mode so using a DSLR camera with a open shutter in a darkened room single frames of the water drop can be captured. A LCD display shows the event delay time and frequency of water drops so one can quantifiy the water drop process. Using a optical sensor to trigger strobe vs matching strobe frequency to water drop frequency by a straight variable rate stroboscope gave me better results.