DIY LED Hood: Prebuild Thoughts...

[GMGQ]

The LEDs game last friday, so I spent the evening gluing them onto the fixture and wiring everything up!

DIY Aluminum Fixture:

I used 2 of the left piece side by side for the main body, and I interlocked and riveted in all 4 sides with the right piece.

Top View:


Bottom View:


Side View:


LEDs:


I was going to install a piece of plastic on the bottom as a splash guard, but I havent gotten around to getting the plastic. But now I'm wondering if it's even necessary. I'll probably hold out.

Grommets for running wires through:


Wired up (48" strip of blue LEDs as Moonlights wrapped around fixture):



Temp electrical station :P


Top view with fans (80mm Aluminum fans with blue LEDs, fitting):


Front View:


Fixture runs COOL TO THE TOUCH on full load. Blues at 800mA, Cool Whites at somewhere over 1000mA. One of my goals was to demystify the belief that you need those honking 20lbs+ Amplifier style heatsinks. Pretty cool that ALL the parts of the fixture are aluminum, from the body to the rivets, and even the 2 fans and the screws are Aluminum. I'm very happy with this LIGHT WEIGHT fixture.

I had made the 8LED Fixture, and now this. It's been really good practice. This second one took me no time at all. It's all about the planning. However, I did not anticipate building this 28LED fixture, so the big fixture for my display tank has been pushed back to next year. I just got a new order of bulbs, so they should hold me over until the next LED build (I'm thinking around 60 LEDs next year).

[Milad]

Nice job!! that looks fantastic. People never believe me when I tell them they can use U-Channel for their heatsink.

Keep an eye on the frags at the top of the tank,t hey might bleach with all the new light.

[GMGQ]

Thanks for getting the LEDs out to me man!

Yeah, just look at CPU heatsinks these days, they now have LOTS fins are literally 'paper thin.' It's all about surface area, and dissipating the heat energy from the surfaces, so that the material can continue to "sink heat" away from the LEDs.

The frags have been accustomed to LED lights, as I had my original 8LED fixture on this tank. Lots of browned out frags have started to colour up under that light, so that test run is what inspired me to do the 28LED fixture. Now I can spread out the frags along the whole length of the tank.

Originally Posted by Milad

Nice job!! that looks fantastic. People never believe me when I tell them they can use U-Channel for their heatsink.

Keep an eye on the frags at the top of the tank,t hey might bleach with all the new light.

[StirCrazy]

Originally Posted by GMGQ

. One of my goals was to demystify the belief that you need those honking 20lbs+ Amplifier style heatsinks.

I don't anyone has ever said you need a big finned heatsink, what I believe has been said is that yes with fans you can get away with smaller and cheeper forms of heat sinks, even 1.25x1.25 al tube.

what has been said though and provin is that if you have a fan failure and are not home to catch it or didn't build over temp protection into your design then that cheeper lighter heat sink puts your whole system at much more risk than a higher watt/in2 heat sink would.

got any pics of it with everything on full?

Steve

[GMGQ]

Well there's no manual of what you should or should not do. I'm just saying from what I've seen in the forums, people who jump into a DIY LED project will typically go with what everyone else has been doing, and go with the big heavy heatsinks, as that is the "norm." Even the online stores that specialize in DIY LED parts are providing these heatsinks, as that is what the market has been demanding.

Even with a massive heatsink, I dont think you can escape overheating issues. I think of heatsinks like batteries/capacitors. Once you fill it up with heat energy, it will be full, and it will not be capable of drawing any more heat from the LEDs. The LEDs are not going to stop generating heat, so the heat has to go somewhere. Therefore I think you still need fans no matter what heatsink you use.

The beauty about a smaller heatsink with more surface area is that it is easier to dissipate the heat, rather than trying to cool down a thick piece of metal. I dunno, that makes sense to me.

Again I refer to CPU heatsinks. They have passive heatsinks like this now:



Oh, and no, no pics of everything on full. It's insanely bright, and the camera just sees one big glare. The blues get totally washed out by the white, so I just turned it down to where I wanted, set it and forget it.

Originally Posted by StirCrazy

I don't anyone has ever said you need a big finned heatsink, what I believe has been said is that yes with fans you can get away with smaller and cheeper forms of heat sinks, even 1.25x1.25 al tube.

what has been said though and provin is that if you have a fan failure and are not home to catch it or didn't build over temp protection into your design then that cheeper lighter heat sink puts your whole system at much more risk than a higher watt/in2 heat sink would.

got any pics of it with everything on full?

Steve

[Milad]

Originally Posted by StirCrazy

I don't anyone has ever said you need a big finned heatsink, what I believe has been said is that yes with fans you can get away with smaller and cheeper forms of heat sinks, even 1.25x1.25 al tube.

what has been said though and provin is that if you have a fan failure and are not home to catch it or didn't build over temp protection into your design then that cheeper lighter heat sink puts your whole system at much more risk than a higher watt/in2 heat sink would.

got any pics of it with everything on full?

Steve

uh? Do you read all my posts or something, that you can say that for sure? Ive gotten flamed on other boards for saying you dont need the oversized heatsinks, you can use aluminium u-channel. I stopped saying it and started selling the oversized aluminium heatsinks but still tell people they can use the u-channel.