Thinking of a new light ..

PetFlora said:

Yeah, when I read the article the thing that jumped out at me was the MC. (In fairness the tech is moving at warp speed) Don't they know about the different voltages/heat? They did say they put something on the board so when individual diodes fail, they don't all turn off. HELLO. Also some o those will lose efficiency a lot sooner

But how about a bunch of 10-20w COBs spread out on a bar type heat sink with passive cooling?

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PetFlora said:

But how about a bunch of 10-20w COBs spread out on a bar type heat sink with passive cooling?

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Mechmike said:

My latest build was an attempt to do just what you suggest. I tried 15 Vero 13 emitters running at 350ma attached to a 1.6" thick serrated heat sink measuring 13.8" x 17". It run acceptably cool but, as always, I wanted more. The drivers I am using now run at 600ma. With the addition of 2 nearly silent 120mm fans and a custom cut & bent top sheet to channel the air it now runs cooler with significantly more light. The heat sink is made from 3 17" lengths of 4.6" serrated fin from HeatsinksUSA joined with silicone based thermal conductive adhesive. Here's a few photos of it.View attachment 3156330View attachment 3156328View attachment 3156329
I guess my point is that it's possible but a little forced air really makes a difference...especially with a monster heat sink.

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stardustsailor said:

Nice airflow design .!
Resembles much the design ,I've used also !

Just tell me ,that fans are sucking and not blowing ...
Yes,they are 'sucking '....
.

Very good design !

Hmm,I see some FR leds there ,also except from 660 nm & NW ...
While on one bar (lower )I can see some 630 nm ...
Nice bars ,also ...
(resemble a lot to Pet's BML bars ... )
WW-BL-NW-630-660 ...Fr ...

WoW !
You must have some nice herb-growth and bud-production ,there !

...
" I guess my point is that it's possible but a little forced air really makes a difference...especially with a monster heat sink ".....

Then,what about of lots of forced air with a monster heatsink ?
...

Really...
Any weight figures of the fixture/ heatsink ?

Fins are made for active cooling ..Serrated ,thin & tall ...base thickness of heatsink(s) ?

Filters on fans ,do suppress (somewhat ) the noise ?
(for sure they decrease a bit the CFM ..)

Thanx .
Cheers

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Mechmike said:

Thanks! It means a lot coming from you. I don't have the electronics expertise you do but I somehow manage. I consider you one of my mentors because of your understanding of electronics and how that applies to our quest for the best.

The fans are Rocketfish brand sold by Best Buy link- http://www.bestbuy.com/site/rocketfish-120mm-case-fan/9462654.p?id=1218108988841&skuId=9462654&st=120mm fan&cp=1&lp=1 They don't give anything but fan speed (1200rpm) but the fans do move some air and quite enough to keep the heat sink nearly un-perceptibly warm without sounding like a departing airliner.

Yes, in addition to the Veros I have 6 740nm from Stevesleds, 28 Luxeon 660nm, and 4 5000k Luxeons, soon to be replaced with 4 Ledgroupbuy 430nm violet blues to get that little deep blue bump at the blue end of the chlorophyll A action spectrum. The Veros are as follows; 6x 2700k, 7x 4000k, 2x 5000k. The heat sink weighs 16lb bare. Link-http://www.heatsinkusa.com/4-600-serrated-fin/ The base thickness is .26" with 1.451" fins.

The fans intake from the top so I assume that they are blowing. Actually the filters are very thin aluminum mesh. I don't think they restrict airflow much but some is inevitable. Installing them didn't seem to change the sound level to me but I am over 6 decades alive so my hearing isn't what it used to be. I only installed them to keep objects out of the fans. Sometimes I get clumsy. I do agree that cooler is better. I haven't measured the heat sink temperature but I can tell that it's barely above room temperature and that pleases me.

The photo is of my flowering chamber. 4 levels of bars to get those big/dense buds all the way down. My last run netted 14 ounces of quality dried Reserva Privada Kosher Kush. I love that strain. I only flower 2 plants at a time so 14oz isn't too bad. My hope is to yield a pound every harvest. The two bottom bars are Chinese 1-watters. Their days are limited now. I just today ordered 50 2700k CXA1304 9v emitters from Digikey to retrofit those bars. The two top bars are all Luxeon ES with a few Osram Golden Dragon deep reds and a few Cree XTE warm whites I had when I built it.

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Rooster99 said:

Nice one Mechmike!! I love it!! I am about to redesign my setup as well. Will look something like this hopefully. I am not happy with my heatsinks. my mounting, my TIM, or the fact that I have to hang multiple separate units. I am going to just epoxy the COBs to an aluminium baking tray with thermal epoxy (can't be bothered getting holders, and I know they will be stuck there for good), and then epoxy the heatsinks to the other side of the baking tray, directly on-top of the where COB is mounted. This will allow me to have a single light panel rather than many smaller units.

Sorry for jacking your thread SDS - Got a bit carried away haha

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stardustsailor said:

Are you sure that the fans are blowing to the heatsinks ?
I can see something that looks like the label of fans ...
Usually that side is the airflow "out " side ..
Air blows out from that side ....
So ,the fans should be sucking from the other side ...
The one towards the heatsinks ...



Pretty cool set-up !

Amazing the diversity of led growing installations and cultivating techniques ...
Let alone the diversity of leds,driver,heatsinks ,etc ...
A world of endless possibilities ..
The most awesome part of dealing with leds ...

Good job,bro !
Cheers !

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Rooster99 said:

Nice one Mechmike!! I love it!! I am about to redesign my setup as well. Will look something like this hopefully. I am not happy with my heatsinks. my mounting, my TIM, or the fact that I have to hang multiple separate units. I am going to just epoxy the COBs to an aluminium baking tray with thermal epoxy (can't be bothered getting holders, and I know they will be stuck there for good), and then epoxy the heatsinks to the other side of the baking tray, directly on-top of the where COB is mounted. This will allow me to have a single light panel rather than many smaller units.

Sorry for jacking your thread SDS - Got a bit carried away haha

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Mechmike said:

Thanks Rooster. You might have a look at heatsinkusa.com They offer a great assortment of heat sinks at what I think are reasonable prices.

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Rooster99 said:

I would love to check that out but I am not in a location that makes it economical. Too much shipping. I found a local aluminium supplier that is willing to sell me 5m lengths of heatsink, but not much here for smaller applications. I also want to reuse the CPU heatsinks that I'm using now so a flat surface like a baking tray will let me attach them rather easily. Its a little dodgy but I think it should work well.

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Mechmike said:

I see... I am a true believer that where there is a will there is a way. As long as you use quality thermal adhesive and get real good contact on the surfaces it could work. You will need to move some air over those heat sinks though.

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Rooster99 said:

No problems there - I'm keeping the fan attached to heatsinks and just sticking the contact patch of the heatsink that normally sits on the CPU directly to the tray. On the bottom side of the tray directly under the contact patch I will mount the cob. This way most of the heat should wick up into the CPU cooler and be handled by the fans. I hope that makes sense...

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thump easy said:

stardustsailor??? are you a women??? just asking if you are that cool!! if your not thats cool too.. that song a girl like you?? he seas his knees are bleeding??? that a cause of some hard core rug burns.. thats all that came to mind sorry dont mind me that LED light looks pimp and the other dude pulling 14 owes 2 plants thats pimp 2

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