DiY LED - Cree CXA3070

@SomeGuy nice work that build looks slick!

@captainmorgan How much were the 4K ADs going for? You can choose from quite a wide range of intensity depending on how fast you want your ladies to veg up. I have used as little as 3W/ft² and as much as 8W/ft² but you could go much higher.

I got them from another member here for $42 each and at 700ma it looks like 8.7 watts sq/ft and at 1.05a it would be 13.5 watts a sq/ft, I'm leaning toward the 1.05a.

captainmorgan said:

OK guys,has anybody come up with a good watts per sq/ft number for vegging. I've got 4 CXA3070 4000k AD's coming and they need to cover 11 sq/ft. Just trying to figure out which driver to get,I was thinking 700ma. Anybody done a spread sheet on these 4000k AD's?

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captainmorgan said:

Here you go,she's taking 425 umoles now.
View attachment 3247720

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captainmorgan said:

I stepped her up to 300 umoles for the last two days and she's gettin with the program,leaves pointing up.

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jeah, it´s not easy with umoles, spectrum and watts.

Looks like 1050ma is my best option,3 will give me 10 watts a sq/ft and 4 is 13.5 watts a sq/ft and at 48% efficient.

Just wondering what all of you guys are doing for cooling your room and or tent. I have 65 sq foot with 1.6k hps light vented ( sucking air from my house ) and the area stays very nice, will i have a problem running 1k led with a 5k btu wall ac? I do live in a hot climate but i can almost get away with running both the hps lights with no vent. Also wondering if i should run the 1050 drivers to give me 9 watts a square foot or the 1.4 amp drivers to give me 11, just wondering how big a plant you can put under one and still get good penetration. any input would be great thanks.

4CXA's, 4 VERO 18, 4 Reds ?

Aluminum U Channel is the frame which is 22"x12" held together with aluminum rivets, 6/32 screws and 8/32 screws. Reinforced with L brackets to support any frame twisting.
4 2" x 10.5" Usaheatsink
For the Veros
2 3.5"x10.5" Usaheatsink
For the CXA's
4 CXA 3000k Z2 Mouser 38.00/ 19.00 Driver Meanwell LPC-60-1400 drivers

4 Vero18 3000k Digekey 13.41/ Drivers Ebay Shining Light 11.87 50w/1750(Which I really think they run at alot less)
http://m.ebay.com/itm/191189496949?&txnId=1029933288009

2 Universal 10" auto fans, I got mine from Amazon they were 32.00.

2 12v 5A power Supplies/ Ebay 8.95 http://m.ebay.com/itm?itemId=111450742537

6" spacing between the CXA's and 5" from CXA to Vero.

Ideal In Sure connestors to tie all the AC together .

You will notice that there is alot of apace on the Vero heat sinks and that is to mount some Deep Red and Red.

The huge fans push so much air i put the Meanwell drivers to the side to get air flow over them.

The Vero drivers are Open Frame so mounted them on a peice of ABS, i cut and silconed the drivers on, the little holes in the ABS are tso air can circulate up and over the drivers.

I have one question and need some advice, every thing seems to be running Great, when i unplug the lights the CXA's go right out. The Veros on the other hand, die out over a 5 second count. Is this normal for the Ebay driver?

I checked to make sure all Loads and Neutrals were right on the VERO drivers and made sure all wires are tightly connected.

The other thing is i need some advice on some good quality Deep Reds and Reds mounted on stars?

SupraSPL said:

It might work but from the datasheet it looks like a very close call as far as vf range.

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Got the Vero 18 5600k powered with a Meanwell Lpc-35-1050. The vf was 3-3.2 at 950ma.

Digikey has some Samsung modules LAM-32LED available in two sizes:
259.00mm L x 250.00mm W for 20.55$
273.00mm L x 216.00mm W for 21.44$
At first glance interesting. I played with the numbers for benchmarking against Vero/CXA:
Powered by the test current of 385 mA (9.2 W), the 3000K 80 CRI yields 137 lm/W (~42% efficiency).Two modules powered by the 290mA ebay driver makes ~45$ for 14 overall Watt, around 7$/PAR W. Mounted on a size-matched plate of sheet metal (or the sidewall of a PC tower) would allow for passive cooling at 89 sqcm/W while a maximum of 10.3 W/sq.ft can be achieved when a flat area is completely filled. I guess distance from the canopy is not an issue. Shall be enough for vegging....side illumination in a cabinet grow... or a PC grow, i.e 5 of them directly applied to the casing of a Big Tower. In summary, these Samsung's are neither powerful nor a bargain, but efficiency and excellent spreading for close-to-the-canopy applications are somewhat unique features.

Hideliho, need some advice limiting the options and pointing me in the right direction, I have never had a COB in my hands.

Goal: Perpetual microgrow within limited space, short bushy plants with lateral root growth as well as short flowering would be beneficial.

Vegging in a PC case, grow area h x w x l is 50x18x40 cm respectively. Shall contain a mother plant and a plant in vegetative stage, thought strongly on mainlining to increase yield/area. Light setup: 6 XML2 T6-4D and a Vero 18 4000K (the Vero is not yet ordered), all in one string @290mA. Any suggestions regarding the suggested color temperature for this scenario?

Flowering in a flightcase, effective grow area is 80x40x40 cm, so aiming at around ?40+? Watt. The options:

1. 1x Vero 29 4K on Arctic Cooling powered by Meanwell LCM-40DA, after stretch supplemented with or replaced by 2x Vero 18 2700K (290ma) on passive copper heatsinks. Reason: Concerned that 3K has not enough blue to avoid stretch during the first half of flowering, while 27K might supply more of reddish light once bud growth sets in. With the COBs, I hope that for a fixed wattage, the distance from the canopy can be reduced furthermore better spreading of light.
2. 1x Vero 29 3K on Arctic Cooling powered by Meanwell LCM-40DA, that might later on be supplemented by ???. What I don't like on 3K (vs. 4K) is that 40% sacrifice around 450 nm for gaining only 10-15% from 580 nm on. Furthermore I somewhat fear stretching when initiating flowering with Vero 3K...
3. 1x CXA 3070 3K, seems the rollitup standard. Can be powered by the 30W fasttech driver, would not allow playing around with dimming, spectra etc. However, in direct comparison, the Vero 3Ks the spectra seems to indicate more output except in the blue region.
   
4. 4x Vero 18 3K powered at 290 mA would yield 8.5W*4 = 34 Watt. At 40% efficiency, 5W of heat have to be dissipated. One on each of the copper cpu coolers (google:26K8805, 2x3x3.5 inches, surface area without considering the fins 270 sq cm, otherwise around 1800 sq cm) I already bought would allow for good light spreading. As I have no practical experience, do you guys guess these heatsinks will stay r e a l l y cool even without any air blowing by, 5W seems like nothing to me?

Any ideas what direction to take?

With a multi-point light source 25 to 30 watts/sq ft is fine. with a single COB I would want to go higher.

Hey Supra!

I finally finished my CXA3070 project. It is not what I envisioned from the start, I mounted all the components on the heatsink bar. My KillAWatt says it is using 241W.

Growerx2014 said:

Hideliho, need some advice limiting the options and pointing me in the right direction, I have never had a COB in my hands.

Goal: Perpetual microgrow within limited space, short bushy plants with lateral root growth as well as short flowering would be beneficial.

Vegging in a PC case, grow area h x w x l is 50x18x40 cm respectively. Shall contain a mother plant and a plant in vegetative stage, thought strongly on mainlining to increase yield/area. Light setup: 6 XML2 T6-4D and a Vero 18 4000K (the Vero is not yet ordered), all in one string @290mA. Any suggestions regarding the suggested color temperature for this scenario?

Flowering in a flightcase, effective grow area is 80x40x40 cm, so aiming at around ?40+? Watt. The options:

1. 1x Vero 29 4K on Arctic Cooling powered by Meanwell LCM-40DA, after stretch supplemented with or replaced by 2x Vero 18 2700K (290ma) on passive copper heatsinks. Reason: Concerned that 3K has not enough blue to avoid stretch during the first half of flowering, while 27K might supply more of reddish light once bud growth sets in. With the COBs, I hope that for a fixed wattage, the distance from the canopy can be reduced furthermore better spreading of light.
2. 1x Vero 29 3K on Arctic Cooling powered by Meanwell LCM-40DA, that might later on be supplemented by ???. What I don't like on 3K (vs. 4K) is that 40% sacrifice around 450 nm for gaining only 10-15% from 580 nm on. Furthermore I somewhat fear stretching when initiating flowering with Vero 3K...
3. 1x CXA 3070 3K, seems the rollitup standard. Can be powered by the 30W fasttech driver, would not allow playing around with dimming, spectra etc. However, in direct comparison, the Vero 3Ks the spectra seems to indicate more output except in the blue region.
   
4. 4x Vero 18 3K powered at 290 mA would yield 8.5W*4 = 34 Watt. At 40% efficiency, 5W of heat have to be dissipated. One on each of the copper cpu coolers (google:26K8805, 2x3x3.5 inches, surface area without considering the fins 270 sq cm, otherwise around 1800 sq cm) I already bought would allow for good light spreading. As I have no practical experience, do you guys guess these heatsinks will stay r e a l l y cool even without any air blowing by, 5W seems like nothing to me?

As far as I remember, supraspl uses 25W/sqft, someone else around 50 W with the intention to go down to 40W or below, due to stressing of the plants. So 34 W are plenty with high yield/sq ft in mind?
​

Any ideas what direction to take?

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I have 2x CXA 3070 dimmable between 0-1200mA on an ebay driver and a Triac-dimmer in a box of 60x30x50cm. Its working like charm.

Fedex guy just came and gave me a present! I think they mark Z4 on the package just to get you excited. Pretty much everything ordered just waiting for parts. Going to run these at with lpc 60-1400 with active cooling for a total of 11 watts per square foot. Led lit reef tank in the back round, i love these things!

@Growerx2014 The CXA loves to be underdriven so if you are going with the 30W drivers I believe that would be a better bet than the Vero. I run a lot of sativa leaning ladies and the stretch with 3000K is no problem. You can wrassle your canopy with a fan or by hand to reduce stretch and create stronger branches if necessary.

I sbelieve the copper heatsinks would get unnecessarily hot without air movement. For passive cooling I recommend 110cm sq /W. Copper moves heat faster but does not radiate heat any better than aluminum so the surface area requirement is the same.

Because you are plannig on running soft you can get great results from 30W sq ft.

Another great option for drivers, these put out about 800mA:
http://www.ebay.com/itm/30W-Watt-High-Power-LED-Driver-AC85V-265V-50-60HZ-Waterproof-USA-Seller-/310948865469

@x.man that setup looks awesome! how long is that thing?

@jay5coat I dont mean to alarm you, but are those from a trusted source? From my limited experience the Z2s have the wavy surround and the Z4s have a smooth surround and a thinner layer of silicon (gold wires are more visible) and the ABs have smooth surround with CXA3070 N printed on them. That was the look of them from Digikey and arrow, but maybe it was coincidence and the pattern does not imply the bin.

Z4 on left Z2 on right. The Z2 came from a Digikey 20 pack and the Z4 came from Arrow in a 100 pack sealed from Cree.

Thanks supra! The heatsink is 48 inches. I used the 5.886 width from heatsinkusa.

@ supraspl Yes i bought them from arrow, they are Z2 which is what i bought but the label on the package says Z4. I noticed someone else had the same thing happen. For a split second you thing you got hooked up but the i saw the wavy edges...Just waiting for a few more things then i can start the build, good thing to i have 12 ladies ready to flower and want to do a side by side just for my own education.

i bought 4 z2's from mouser, and they have 3070N written on them and no serrated edges. Does this mean that i might have gotten AB bins? They were also packed in a padded box, and not in the plastic containers i have seen others get their COB's in.

That is a good question SK. Maybe the newest CXAs all say CXA3070N or maybe they are shipping ABs as Z2s? I tested Z2 Z4 and AB side by side and the light meter showed an expected increase from each bin but the difference between the Z4 and AB was not as high as I expected from the paper work.

SupraSPL said:

@Growerx2014 The CXA loves to be underdriven so if you are going with the 30W drivers I believe that would be a better bet than the Vero. I run a lot of sativa leaning ladies and the stretch with 3000K is no problem. You can wrassle your canopy with a fan or by hand to reduce stretch and create stronger branches if necessary.

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The lower prices for the Vero (expecially pronounced with smaller cobs, i.e. Vero 10) compared to CXA makes the Vero more interesting as it fosters underdriven operation, but contradicts with the fact that Vero is not show significantly increasing efficiency when underdriven. That was mindf**** at first, but simply means Vero loves to be driven hard... BTW, if we assume that the missing binning of Vero results - averaged- in a better than specified efficiency, the driving current that results in equal-efficiency of Vero and CXA shall be lower than what follows from the plain numbers in your XLS-sheet.
Fan is installed, I slightly crush the stem in week 2 to increase strength.

SupraSPL said:

@Growerx2014
I sbelieve the copper heatsinks would get unnecessarily hot without air movement. For passive cooling I recommend 110cm sq /W. Copper moves heat faster but does not radiate heat any better than aluminum so the surface area requirement is the same.

Because you are plannig on running soft you can get great results from 30W sq ft.

Another great option for drivers, these put out about 800mA:
http://www.ebay.com/itm/30W-Watt-Hi...V-50-60HZ-Waterproof-USA-Seller-/310948865469

Click to expand...

I like that driver but shipping to EU is a multiple of the product cost
No doubt they will get unnecessarily hot, but adding a fan is a no option when considering the Arctic cooling price and proven performance. And I have already bought these copper heatsinks and somehow just like these beefy 3-pounders with over 4500 sq cm surface area. Problem is that 110sq cm/W is for free convection, which is not the case for these small gaps between the fins. Spec sheets for other "passive" CPU heatsinks I found are of no use. They all assume some airflow for the published K/W values or graphs.

Anyhow, I came up with a final decision what COBs to order.

Vegging area:
- One Vero10 5K 70 CRI for PC-tower vegging area to enhance the 290 mA XML2 string.

Flowering area:
- One CXA3070 3K 80 CRI on arctic cooling will be in the center of the light, preliminary powered at 290mA (10W @47%), later on maybe by Meanwell LCM-40DA or a 500-900mA rollitup-reputated, but unbranded china driver like the JHX.
- Four Vero10 on two strings at 290 mA, passively cooled by the copper heatsinks and placed at the corners of the lamp (4x 7.5W @ 33%). Not much worse efficiency than a 400W CMH, maybe comparable to my 70W CDM-T. But hey, we are talking about a quite cheap 30W light designed with the drive-me-harder characteristics of Vero in mind. For test purposes, I can mount up to four of them on one heatsink and experimentally compare the real-life performance against the calculated +40+ watts (under the invalid assumption of free convection).


Last question:
What color temperature(s) would the forum be interested to see for the four Vero10? Sure they will all grow buds. I thought on the 2700K (efficiency values couldn't get much worse and Vero seems to prefer being reddish) but are willing to go up to 4K.