Very Nice—That light is almost as big as the BLF GT—— JK
Did the water eventually get hot in the jar
Not really. Probly the longest I have run it was 10 minute bursts. This took room temp water up a few degrees, but not even what I would call warm.
completely “cool” project, thanks for sharing 
That Brass tube is pulling lots of heat also—Have you tried without the water flowing
I thoroughly enjoyed this video! You ‘running’ at the same speed as the car was awesome! Does the reflector have a window?
Great video and fun to watch.
Another Cooling Idea?
.
.
I wonder if anyone has tried to cool a LED using Glycerin?
It is a nice clear viscous liquid with very low electrical conductivity.
Encase the LED and wiring inside a small glass vial and circulate glycerin to keep it cool.
Should work ok.
Perhaps someone here with necessary tools etc may try this next.
when it comes to thermal path from the MCPCB to water it would have been more useful to cut a pattern with a CNC to it than reducing the thickness
they basically push the water against the copper like you did, but increasing the surface
just copying from PC watercool blocks
LOL’d, liked and subscribed, nice work Matt
Good stuff, thanks for sharing.
Next up, an AIO CPU cooler?
Nice!
Now for the next step:
What a terrific video! It’s sure to be shown many times at your sanity hearings. 
Lol for that bike light its totally overkill beyond useful
You blind every other vehicles on the road and ruin your night vision when you got to look left or right
Now THAT is a great bike light. Sort of light a police helicopter might use…
Was the ride through the Black Forrest perhaps.
I just left it open for this project, no glass.
Nice work Thanks for sharing.
They’ll have to catch me first!
Just to be clear, that’s not my light. I just follow the guy on youtube and thought it fit into this thread. Unfortunately he only makes bike lights.
iirc someone on cpf build a rc plane with water cooled light, with like a dozen of xml’s
I remember that. It was like 2 rows of 8 (I think) each generation 1 XMLs, with coils that ran outside the plane.
I have been folding and tearing my brain trying to figure out how to use air or water for cooling a light to extend the period the light can run in its brightest mode. The short run time at max brightness is kind of the lame part of flashlights. More than kind of.
I don’t want to hurt your feelings, because I think the arrangement you put together is awesome, but I think the implementation needs some tidying up to make this a practical mass produced light. I am thinking you probably thought of that.
When epoxy is available, you should never use tape. Science has proven every doubling of the epoxy yields an eightfold increase in awesomeness of the final product. Not even duct tape can match that performance.
In all seriousness, THIS SHOULD BE A REAL PROJECT. The Giggle team is going to be wrapping up shortly. I’d say now is the time to start getting the interest list going for this one and a more serious model of how this can built for reals.
I did not notice a much heat sinking except the water flowing against the back of the emitter plate. I had been thinking you would need the whole head with pipes running through to have a shot at keeping that thing cool. Prototype I, your work, proves that is not necessary.
The production model is going to need a much smaller reservoir and fins somewhere for losing the heat.
Regarding the coolant. Maybe air, water, glycerine. I don’t know why everyone thinks glycerine is such a great idea. Basically the big decision is air vs. liquid. The most exotic possibility would be a liquid that boils at the target temperature for the emitter, then condenses as it flows through the system for dumping heat out of the coolant. The advantage of a liquid like that is boiling it consumes the most heat providing the most efficient possible system (least amount of fluid required for a given amount of heat pumped away from the emitter). I don’t think we should aim for that, because it would work only within narrow conditions.
Air is simplest but water is much better coolant.
The challenges will be making the unit compact and not too noisy for the pump or fan. Dealing with noise is best done with tuned pipes that dampen the sound. Ever hear an RC gas car with and without its tuned pipe? Without the pipe it sounds like a chainsaw. With the pipe, it is really quiet. Whether we use air or water, we need to tune out the sound.
Running cold water against the plate with the emitter mounted on it a great approach. We need a way to monitor the temperature of the spots that fail from heat.
I think your humor might mask the serious potential and intelligent innovation you put into this. Nice work.
s. Your video where you first had a GT for testing is what got me interested and that is how I got into the group buy for the GT. You are a good video man.
s. Nice work with the ice tray. Skipping away like that was a perfect way to avoid attention.
Like a flamethrower, except it throws light instead. :laughing:
If car headlights are coming towards me I simply aim the light downwards at the road, you’d have to be deaf if a car snuck up on you at night when everything is much quieter