400w CXB3070 LED build

Greengenes707

Well-Known Member
I'm seeing taped up wire. At least use electric tape.
At least know what you're talking about.

That is kapton tape...originally made by DuPont. It is heat resistant to 400C, electrically isolated, and leaves no residue even if you take it off and reposition. So when the heatsink heats up and your electrical tape is melting off leaving a residue and your wires are drooping...his will be secure and tight and he will be telling you what to do.
 

Positivity

Well-Known Member
At least know what you're talking about.

That is kapton tape...originally made by DuPont. It is heat resistant to 400C, electrically isolated, and leaves no residue even if you take it off and reposition. So when the heatsink heats up and your electrical tape is melting off leaving a residue and your wires are drooping...his will be secure and tight and he will be telling you what to do.
DC from the driver looks scotch taped gg....hard to see..
 

doz

Well-Known Member
Its clear electrical tape (look it up, they make it). Its also temporary to test. But by all means, continue to make assumptions about "scotch" tape. Do you really think I would use scotch tape to temp wire $470 worth of electrical goodies? :?
http://www.amazon.com/Duck-1016266-4-Inch---60-Feet-Electrical/dp/B001AXFDK8/ref=sr_1_4?ie=UTF8&qid=1427594964&sr=8-4&keywords=clear
http://www.amazon.com/Duck-1016266-4-Inch---60-Feet-Electrical/dp/B001AXFDK8/ref=sr_1_4?ie=UTF8&qid=1427594964&sr=8-4&keywords=clear

No thermometer or thermocoupler. I am not too worried about the layout being close to the perimeter. We will see if I start dropping wattage. That 230mm fan should be able to push plenty of air to keep them cool.

And as far as tapping and driller, I did not tap. I may venture into that on the next one as I did not even think about it honestly. I used 6mm screws and nuts. The nuts fit perfect (although a pain to install) between the heatsink fins so once they are started, they do not need to be held with a wrench. Do not have to worry about stripping aluminum taps either that way.

http://www.amazon.com/Duck-1016266-4-Inch---60-Feet-Electrical/dp/B001AXFDK8/ref=sr_1_4?ie=UTF8&qid=1427594964&sr=8-4&keywords=clear electrical tape
 

Greengenes707

Well-Known Member
Its clear electrical tape (look it up, they make it). Its also temporary to test. But by all means, continue to make assumptions about "scotch" tape. Do you really think I would use scotch tape to temp wire $470 worth of electrical goodies? :?
http://www.amazon.com/Duck-1016266-4-Inch---60-Feet-Electrical/dp/B001AXFDK8/ref=sr_1_4?ie=UTF8&qid=1427594964&sr=8-4&keywords=clear

No thermometer or thermocoupler. I am not too worried about the layout being close to the perimeter. We will see if I start dropping wattage. That 230mm fan should be able to push plenty of air to keep them cool.

And as far as tapping and driller, I did not tap. I may venture into that on the next one as I did not even think about it honestly. I used 6mm screws and nuts. The nuts fit perfect (although a pain to install) between the heatsink fins so once they are started, they do not need to be held with a wrench. Do not have to worry about stripping aluminum taps either that way.

http://www.amazon.com/Duck-1016266-4-Inch---60-Feet-Electrical/dp/B001AXFDK8/ref=sr_1_4?ie=UTF8&qid=1427594964&sr=8-4&keywords=clear electrical tape
My thoughts exactly with clear tape. I was saying to myself, no way did he have everything else right and then do that.

I use the nut a bolts for my frames...no wrench/pliers too. Never even crossed my mind for the holders...great simple idea.
 

Mellodrama

Well-Known Member
"I must say, those COB holders kind of suck..."

Yeah, they are a little fussy to install but I'm sure you were getting better by the third or fourth one. Did you carefully inspect for bits of crud between the sink and the COB?

Have you considered building a shroud of some kind? Reason why I mention this is because you've got one huge fan sitting in the middle, and your lights are way out on the corners.

There are four or five fins directly behind the lights along either edge of your aluminum plates, ready to carry away most of the heat. But those fins hardly get any of the energy the fan's putting out. The fins that get the most prop wash are in the center of the plate. They'll get lots of air movement. Those fins are not directly behind your lights. 80% of your fan's output is washing through channels that aren't picking up much heat from the COB's.

I think your design will work OK and you'll be perfectly happy with it as is. I just think it would be an improvement to incorporate a sheet metal shroud between the sink and the fan so prop wash could be distributed across the entire plate rather than concentrating it where you don't have any heat-producing devices.
 

doz

Well-Known Member
Oh yeah, there is definitely room for improvement! I learned quite a bit on this build as it is my first. After having the parts in hand and understanding them all a bit better, I will definitely be making improvements on my next build. I do plan on building a complete case eventually as well as a shroud. I may even switch to 2x 140mm fans as well as that would not be too difficult. I will see first if I have an issue with heat (which I doubt I will honestly. I fired them up and the heatsink was pretty cool even without a fan). I kind of feel that the cobs will transfer enough heat through the other parts of the heatsink honestly. We will see for sure though.

As far as stuff between them, there was nothing. Prior to installing each one, I cleaned them with alcohol and then blew the dust away with a high pressure duster. I used Prolimatech PK1 for TIM and the one thing about those cob holders is the really hold down the COBS well so they make great contact.
 

Sxott

Well-Known Member
Im building the same light for my second build. (still working on first) Can you describe more about how much heat is being generated? How much is both of them warming up your tent and how are you venting it? How warm does the heatsink feel to the touch after it has warmed up and running awhile? If your fan failed , do you think your cobs would survive?
 

doz

Well-Known Member
Ill let you know shortly. Did not get it hardwired yet and I wont have it in the tent for at least another week. Still have a little bit to veg. It will be tough to see if they heat up my room. I have a 1000w HPS that only heats it up about 2-4 degrees due to how I run my exhaust and negative pressure.
 

doz

Well-Known Member
Heatsink is barely warm to the touch even next to the COBS. VERY cool and there is some air blowing through all the channels. It is not losing any power either so I dont believe they are scaling.
 

doz

Well-Known Member
Thanks man! Its rough, definitely not perfect but its functional which is the most important thing! I have high hopes that I can pull at least 1.2 GPW as I pulled .58 GPW on my last grow with the same strain under HPS. This should be a good test for these little LEDS!
 

doz

Well-Known Member
Yeah, after doing it I agree but I did not understand some of the lighting characteristics. Just lack of experience really as I know with HPS you lose a TON of light on the edges. These seem to cover pretty well. Regardless, the sink right next to the COBS is barely warm to the tough, not hot at all.
 

the dopest

Well-Known Member
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