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Custom Cree LED light build for evil par38 bulb

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Thought I'd share my most recent project! I have a aquapod 12g with a Evil Par38 bulb over it.






I really like the bulb but wanted more actinic for color and night time viewing. I decided to add some CREE LED bulbs from RapidLED and design a custom ring for the Par38 bulb that hangs over my tank.


Here is the ring with a few bulbs attached so far. I had it waterjetted out of aluminum. I was going to anodize or paint it black but I decided I liked the silvery look.



Here is a closeup of the bulb and heatsink sandwich. I used thermal grease in between all of the metal parts for heat conductivity. It runs quite cool, I actually think the fins were overkill, but they look neat.



Test fitting on the back of the Par38 bulb. The ring just rests on the ledge of the par 38 bulb. I removed the shield from my light because I was a little worried about all that LED heat building up under there.







Now the bulbs are all mounted, and soldered together, and the 60deg lenses are installed with a little thermal epoxy. Btw, if you're doing this, dont use superglue to adhere the lenses - I hear it can cloud the lens surface when curing.





And here they are running..!







I used a LED driver that allowed me to use my reefkeeper system to adjust the intensity, but the RK module is quite expensive. For now I am using a radio shack power supply with adjustable voltage ranges to control the brightness. Its quite hard to photograph the tank with all that blue, so I gave up. :) It does a great job of bringing out the colors and with the main light off, the tank looks amazing. I'm seeing colors I never saw before.


I tried using some UV lights and even a natural white bulb on the ring before I went all blue, but the white lit up the tank too much and negated the blues, and the UV didn't seem to make a difference, and since they are new, there are no lenses available for them, so I took them off so the ring looked more concise.


Thats it!

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looks like some sort of perverse surgical bot

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Pretty awesome man. I like the look of it. It's unique, and looks like it alters the color quite a bit. Hopefully to your liking!


Are the heatsinks glued on there? or are they screwed down also?

Edited by ajmckay

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We thought of doing something similar for moonlights or added actinic, but the direction left a ring around the tank and for smaller tanks it didn't work out well because too much spill, are you finding that an issue?. We have something coming out that we worked up, but this is some awesome craftsmanship. You own a CNC machine?

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Thanks for the kudos! :)


ajmckay, they are just sandwiched with the screw, which is nice because I can change LED's later if I want with little effort/mess. I only used epoxy to hold the lenses on. I did use thermal compound between the metal bits. The ring runs very cool. On max brightness (set at about .9A) you can touch the heatsinks and they are quite cool. I dont think I even needed to add them, but they do look interesting. :)


Mike, I dont see a ring of blue. I think if maybe I used 40deg lenses, it might?! I dont mind too much about light spill. It seems to light evenly.. I can spin the ring and I dont see any change in blue rotating around in the tank..


I dont have a cnc machine.. the ring was water jetted out which is a much better process for this sort of cutting. BTW, if anyone wants a ring, I'll sell it for $45 shipped. I have an extra. :)

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I dont have a cnc machine.. the ring was water jetted out which is a much better process for this sort of cutting. BTW, if anyone wants a ring, I'll sell it for $45 shipped. I have an extra. :)


Very cool, nice work, I am glad it worked out for you!

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Lucky waterjet owner, I'm milling-- wood. Atleast it's one of the hardest in the world, although it's still just wood.

Your light modification looks really nice and has a neat industrial look to it.

Edited by jm82792

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