DiY LED - Cree CXA3070

CaliWorthington

Well-Known Member
Yes if you tape the COB, paste is used. I'm pretty sure the COB holders involve no paste.

I don't have a parts list, but it's basically the COB, COB holder or kapton tape, heatsink, some wire, a driver, and a fan. Throw in some low voltage spade connectors and heat shrink wrap, and some wire or chains to hang the heatsinks, that's about it.

If you read through this entire thread, and maybe a few others, I'm sure you'll figure it out no problemo.
 

DarthBlazeAnthony

Well-Known Member
Are the cost savings worth attempting to build on my own? A nice 600w led cost me $240...Im thinking I could build one that is more efficient. Appreciate it...so many great ideas here!
 

captainmorgan

Well-Known Member
Yes if you tape the COB, paste is used. I'm pretty sure the COB holders involve no paste.

I don't have a parts list, but it's basically the COB, COB holder or kapton tape, heatsink, some wire, a driver, and a fan. Throw in some low voltage spade connectors and heat shrink wrap, and some wire or chains to hang the heatsinks, that's about it.

If you read through this entire thread, and maybe a few others, I'm sure you'll figure it out no problemo.
You always need TIM (thermal interface material) between the COB and heatsink to help transfer the heat no matter how you fasten the COB to the heatsink. You can use paste with a holder or tape,or just use a thermal adhesive but that's permanent. I would also recommend useing a non conductive TIM.
 

epicfail

Well-Known Member
Are the cost savings worth attempting to build on my own? A nice 600w led cost me $240...Im thinking I could build one that is more efficient. Appreciate it...so many great ideas here!
You can also read Gaius's build here. The cpu cooler is a cheaper route than the large heat sinks because you can get them at local computer stores, shipping large chunks of aluminum can be expensive. Also you can get cheaper drivers than the Meanwell's.
 

SupraSPL

Well-Known Member
I pull air away from the heatsink with my fans...have awayz done this...i guess they both work... :)
You may find a significant drop in temp by flipping the fans so they blow into the fins. The fans on CPU coolers are designed to blow into the heatsink. I tested that theory in my computer and sure enough temps were much higher with fans sucking rather than blowing. It makes sense when you think of it in terms of air resistance. The side of the fins are not shaped well for an air intake.
 
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SupraSPL

Well-Known Member
Are the cost savings worth attempting to build on my own? A nice 600w led cost me $240...Im thinking I could build one that is more efficient. Appreciate it...so many great ideas here!
Any LED is claiming 600W for $240 is unfortunately lying to its customers (unless you meant $2400?). Actual dissipation will probably be about 100W of low quality LEDs and you would be much better off with HID.

A quality LED will cost about $2.15-$3/W (LED dissipation). The Onyx Bloom cost $2.15/W. A diy COB lamp could cost as low as $1.50/W if you are resourceful, and it would be much more efficient than the Onyx Bloom. You can make it as small as 52W for about $75 or scale it up to cali worthington size and you can still run on 120V circuit.
 
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Golderado

Member
Thank you very very much Supra, Cap’n Morgan, Gaius and all others who have contributed such amazing, clear and easy to fallow information to the masses. These threads on COBs and "how too's" are exactly what Ive been waiting for and it seems a lot of others have been waiting for something like this to come along as well. I have literally been checking the forums every few months hoping for something to change. I always wanted to switch to LED but it always seemed to be not quite worth it in the end. Well not anymore thank to you guys!!!

It looks like hunting down a good quality affordable driver is a challenging one. Please continue to post updates on which ones look good.

A few questions if you don't mind.... :)

My "area" has two sides at about 3.5ft X 7ft ... So I was thinking 4 fixtures per side with 4X CXA3070 3000k per 32" heat sink. Strictly flowering area. Due to my wife having her hands directly on my sack at all times I would only be ordering the materials for half at time. :p

- Should I add a 5000k per heat sink? Or any other suggestions?
- Can we post some pictures of your driver/wiring organization please?
- Mean Well Brand drivers are guaranteed good quality just a little pricey?
- I will be looking at a distance of about 30ft of wiring for all those separate drivers... Is this still a good idea? Worth it? Or any suggestions?
- I would be looking at 32" heat sinks... which is a good chunk of money. I have seen few aquarium guys use "U" channel or
"T bar" or other DIY things for the heat sinks. Any ideas or suggestions welcome here as well.



Thank you so much guys, such a wonderful, affordable way to upgrade our lighting.

I cant THANK YOU enough!!!
 
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churchhaze

Well-Known Member
So I ordered some stuff.. and i think I may have over-engineered this a bit...

Seeing these sinks in person makes me think I could put all four vero 29 on one sink at full power and still have passive cooling.

Now that I see how great these sinks really are, I feel bad tapping them.... even if they only cost 12 bucks a piece.

Here's what my plan was. These are the 3.950" profile cut to 4". Amazing work.


IMG_0242.JPG

IMG_0243.png
 

CaliWorthington

Well-Known Member
Those heatsinks look like they're made for giant MOSFETs or something. The only thing about putting 4 Veros so close is, there will still be a lot of heat coming from the front of the COBs, might be too concentrated. I would still run them soft. Though I think you're kidding, 4 won't really fit on there, will they?

But I'm not the expert, you know. ;)
 

churchhaze

Well-Known Member
I don't plan on putting 4 of them on, but with them all in front of me, all 4 do look like they would fit snugly. Yeah, the people commenting on that 3.950" profile were saying they were making class A power amps, which are very inefficient, but the best audio fidelity.. Class A amps are mostly heat sink by mass.

My original plan was 1 each. Now i'm thinking a bunch of vero 10 can go on the perimeter?

Those heatsinks look like they're made for giant MOSFETs or something. The only thing about putting 4 Veros so close is, there will still be a lot of heat coming from the front of the COBs, might be too concentrated. I would still run them soft. Though I think you're kidding, 4 won't really fit on there, will they?

But I'm not the expert, you know. ;)
 

purplegrower02

Well-Known Member
Just wanted to give a little tip here.

some people use spade connectors for easy cob/fan/driver changes but i take it a step father and use RCA connectors since they have a better connection use gold as a plating and have very little resistance.

You can get 25 packs dirt cheap and their color coded or use a female for + and a male for - so you can't mix them up.
 

DarthBlazeAnthony

Well-Known Member
Just wanted to give a little tip here.

some people use spade connectors for easy cob/fan/driver changes but i take it a step father and use RCA connectors since they have a better connection use gold as a plating and have very little resistance.

You can get 25 packs dirt cheap and their color coded or use a female for + and a male for - so you can't mix them up.
I'll be adding RCA connectors to the parts list. Thanks for the tip. Is there a complete COB build list available anywhere?
 
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