DIY LED Using 10 Watt Arrays

[mike31154]

This coming April will be the 2 year mark since I've put this fixture into service. I'm finally preparing a proper top for the thing. All the LEDs are still going strong but the 27 heatsink fans are becoming a nuisance. They are cheap & I suppose I should have expected the odd failure but it's starting to get old with 5 or 6 failures & many of them are getting a tad noisy. Time for a redesign in that regard.

Larger heatsinks that are supposed to provide adequate cooling of the 10 watt multi chip LEDs without a fan have started showing up on eBay so I ordered a batch of 10. They came in recently & I've redone the center rail of 9 LEDs with them. They come drilled/tapped complete with screws to mount the 10 watt multi-chips. Instead of using angle aluminum I opted for a piece of U-channel I had laying around from my old MH/T5HO Frankenfixture. Drilled a single hole in the back of each heatsink, tapped it & screw mounted with a blob of heatsink compound, making the U-channel an efficient contributor to the cooling process.



Running for about a week now & so far so good. Vewy, vewy quiet! The U-channel gets quite warm but not hot enough to burn fingertips. I had to remount the SMD5050 strips used for supplemental lighting because they'd been attached to the aluminum angle of the original rail. No biggie, but they're a bit higher now, attached to the wood braces of the fixture frame. The new rail weighs only slightly more than the original.

For the cover, I've cut two arc-shaped end pieces out of the same material used for the frame & my idea is to span these with strips of wood, effectively hiding the mess of wiring. Spaces between the wood will allow warm air to vent and I plan to add a couple of larger fans to boost circulation. I have 20 more of the large heatsinks on order to replace the outer rails, so I'm thinking additional flow to keep things cooler will be required.

I've laid some thin pine slats left over from another project on to the end arcs, noting that they sag in the middle due to the 4 foot span. Might have to rethink that & go with very thin plywood that I can bend to shape over the end pieces. Will need to add slots or holes to ventilate. Or I could go with some corner molding, which might hold it's shape a bit better, but not sure I'd like the look of that. Whatever I decide, I'd like to keep it as lightweight as possible. If anyone has ideas, I'd be glad to hear them. I'd like to stick to wood as a material. A couple of coats of finish & the thing should look quite pleasing to the eye.