DIY Cree XML LED Lighting for 150G

[Hoppy]

That hanger idea works great and looks great! Now, If you can just borrow a PAR meter and make sure you have the amount of light you want.

[fizzout]

Originally Posted by Hoppy

That hanger idea works great and looks great! Now, If you can just borrow a PAR meter and make sure you have the amount of light you want.

Thanks, Hoppy. I would really love to measure the light level. With the reflected light off the glass cover, I wonder how much light is getting through. According to your formula, I think it is enough, but that does not account for the reflected light.

[Pickled_Herring]

Best aquatic use of 80/20 ever! What kind of heat are you getting off the extrusions? I'm sure it's minor with that much aluminum. I use 80/20 at work and it's like working with a big erector set. It makes a very neat looking package. Nice Job!

[fizzout]

Originally Posted by Pickled_Herring

Best aquatic use of 80/20 ever! What kind of heat are you getting off the extrusions? I'm sure it's minor with that much aluminum. I use 80/20 at work and it's like working with a big erector set. It makes a very neat looking package. Nice Job!

Thanks for the complement. I really do like these aluminum extrusions. They also have a very nice finish, which gives the lights a professional look. As for heat, the Cree XML LED do get warm running at 2.5 amps. But even without a fan, I can place my hand on the aluminum without it hurting. However, when I have a fan blowing on the lights, the aluminum is barely warm. I would definitely recommend a cooling fan to anyone planning on using these extrusions to extend the life of the LEDs. I will be adding "fins" to the XML LEDs to help along with the heat dissipation so that it doesn't get as warm. I'll make an update once the fins are installed.

In a previous post, I talked about having to replace one XML that went bad. I wonder if the LED adhesive had some air between the LED star and the aluminum to where the junction temperature exceeded specification. That would explain the problem. Maybe I should have used arctic alumina thermal adhesive instead of the double sided thermal adhesive tapes.

[fizzout]

My "fins" arrived and I attached it to the LED heat sink using thermal adhesive. I'm not sure if it made too much of a difference, but I decided to continue to use a fan to keep cooling the LED so that they remain cool to the touch. Here is how the lights look now.

[monkeyruler90]

Looks amazing! I'm planning on building an led light with XML U2s and was wondering how hot they were going to get. Thanks for posing your experiences with them!!

[fizzout]

Originally Posted by monkeyruler90

Looks amazing! I'm planning on building an led light with XML U2s and was wondering how hot they were going to get. Thanks for posing your experiences with them!!

Thanks. I really enjoyed making this light. Everything fell into place very nicely. Ultimately, I don't think the LEDs are getting too hot (since I can touch the aluminum without discomfort when there is not fan). Still, the spec says that the LED will last indefinitely when kept at 30 deg Celsius so I'm using a fan across them. I don't know, I will probably replace these lights sooner than before the LEDs wear out.

[monkeyruler90]

Originally Posted by fizzout

Anyhow, I wanted to warn everyone that optics for XML are not readily interchangeable. However, the XML LEDs from LEDGroupBuy fit perfectly with the optics, as they had opposite side soldering pads that matched the optics.

eek
so i received my LEDS from Rapidled.com and the optics from ledgroupbuy.com only to learn this lesson the hard way! The cut outs don't match the pads of the stars... guess i'm going to have to use the soldering iron to melt the plastic around the holes

[fizzout]

Originally Posted by monkeyruler90

eek
so i received my LEDS from Rapidled.com and the optics from ledgroupbuy.com only to learn this lesson the hard way! The cut outs don't match the pads of the stars... guess i'm going to have to use the soldering iron to melt the plastic around the holes

I know how you feel. You might consider using a Drumel tool instead of the soldering iron, which was a little hard to control. I wish I had thought of that before. Make sure you leave enough of the double stick adhesive to stick on the star, though I didn't have any issue in that way.

[jcgd]

I left the little holder part off and only installed the actual clear cone part of the lens. Works fine for me, just an idea. The white lens holder was a horrible fit. Between the start and my solder job, there wouldn't be much left by the time it would fit.

[fizzout]

Really? I didn't even think that the lens could be taken out of the holder ... duh ... feeling stupid now.

[jcgd]

Oh, maybe we have different ones. Mine came in two parts and you are supposed to snap them all together.

[fizzout]

Originally Posted by jcgd

Oh, maybe we have different ones. Mine came in two parts and you are supposed to snap them all together.

I think you are right. I checked one of the spares and it's not obvious that it can be taken apart and used without the holder. Where did you get your lens?

[monkeyruler90]

Yeah I used the Dremel flat disk attachment to cut out a hole on the side. Fits pretty well now.

I wish LEDGroupBuy would say something about incompatibility with other stars

[jcgd]

Originally Posted by monkeyruler90

Yeah I used the Dremel flat disk attachment to cut out a hole on the side. Fits pretty well now.

I wish LEDGroupBuy would say something about incompatibility with other stars

I used only ledgroupbuy. And they were still incompatible!