72 Watt Rapid LED Pendant Build

Ok... Figured I would post my work.

I built the original version about 6 months ago. I had it suspended in a hood that had fans moving air through it. These fans were not near enough cooling for this light. I ended up ruining almost every LED on it from heat soak.

It originally had Cree XR-E Cool Whites and Royal Blues in a 50/50 ratio with 60 degree optics. I replaced the XR-Es with the newer R5's, keeping the ratio and optics the same.

For the upgrade, I added sheets of plexi to hold everything in alignment and direct air flow better across the heat sink.
I used some aluminum tubing to create spacers between the plexi sheets and stainless hardware to bind it all together.

Comments welcomed.

 

Sorry about the first build

What size heat sink are the LEDs on?

And I'm a bit confused, is there a hole in the plexi below the fan for air to get through?

 

It is a 6"x9" heat sink.

There is a hole in both of the top pieces of plexi. This second middle piece forces every bit of air from the center of unit through the aluminum fins. I was worried that it would not cool as efficiently without this piece.

 

Ohh okay, now I see. I thought the fan was just on top of straight plexi at first. Interesting idea, is it keeping them cool?

I'm doing a DIY LED in two months with the same amount of LEDs on the same size heat sink, so I'm very interested in your build!

 

I will let you know when I get it hung tonight. ;D

When it was originally running, I could not touch the heat sink without burning myself, no joke. This thing got very hot.

I have done a few bench runs, and the fan and plexi channel seem to be doing their job. This is where I wish I had a digital temperature gun.

 

OK, I got it hung and running. I used a pair of J-bolts to hang it. These allow for a solid mount, but I can easily remove it for maintenance. As for the fan, it keeps the heat sink absolutely cold. I should have no heat soak issues now.

 

Looking really good! It's a GREAT active cooling design. Airflow should be a lot more efficient.

Congrats on making the top page! (I think Matt Rogers placed it there. )

 

Thank you. I put a lot of thought into the design of this due to the cost of my first mistake.



Thanks Matt! 1st time on the front page. ;D

 

nice looking light!

 

Looks sweet!!