DiY LED - Cree CXA3070

Hello PF welcome to RIU.

1- CXA3070 3000K Z2 bin just sold out on digikey but there are used ones on eBay or in bulk on Arrow. Cannabare is working on acquiring the 2700K in Z2 bin but the order is currently on waiting status. The 3000K Z4 bin will be available soon.

2- The 2700K Z2 would be slightly better than the 3000K Z2. It is slightly more efficient and has a slightly better spectrum.

3- Very nice heatsinks! Whether or not they will be sufficient for passive will be experimental, but if you do add a few small fans at 5V they will drop temp significantly.

4- Yes I do believe adding deep red and royal blue would be beneficial to the spectrum and they would ideally be run at ~700mA. I recommend Steve's LEDs to get the Luxeon ES deep red EX6 bin and the Luxeon ES royal blue M4R for blue. If it is too much blue for your preference, you could use 4500K XM-L2 U2 4C. You can see an example of the ratio here. Which 50V driver are you referring to?

5- You can use very little light for a small mother. Just enough to keep it growing, 1 or 2 watts. You could use a single XM-L2 U2 4C.

Good luck!

Status update Cannabare! Great post Supe!!!

Don't you guys want a lower CRI for bloom? Has anyone started switch with high CRI to minimize stretch and stress, then switched to lower CRI?

Thanks, hope its okay to ask noob questions in your thread and validate what I learned?

1- CXA3070 3000K Z2 bin just sold out on digikey

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Shipping is expected in around 3 weeks, says their website.

I would prefer getting two 2700 from

Cannabare

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but cannot PM him!?

2- The 2700K Z2 would be slightly better than the 3000K Z2. It is slightly more efficient and has a slightly better spectrum.

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Better spectrum I was assuming, but in what way more "efficient"? I would have assumed that cet. par. lm/watt would decrease, right? ->Radiation efficiency, (micromoles/(m*m*sec)?

BTW, regarding the unit conversion calculation i read about in the ?CXA analysis thread?: There are freeware tools like Digitize It (my choice when urgdata needs to be extracted from literature), Engauge Digitizer or Digitize Plot To Data 2.2.2 for getting numbers back from graphs.

3- Very nice heatsinks!

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...would not have found them without the guys here, credits. Anyhow, your "nice" valuation of this heatsink and temperature measurements on yours as well as my experience with semi-passive cooling of my CDM-T by turbulence from my USB desktop fan convinced me that this will likely be not necessary. I assume that 40 or even 50 Watt can be easily dissipated without active cooling. Furthermore sounds like I will settle with a 700 mA COB with 4 additionl stars...

4-
I think you supplied the wrong link, or I don´t get the context. But I remember a post from you on 5? XM-L2 plus red. I have no substantiate reason on how much additional deep red and how much royal blue to add. Except for the COB, there is space left in the corners of the heat sink plate for four 20 mm stars, either colored or XM-L2s. So except adding blue and red, I assume for the younger of the flowering ladies more "more blue" might be good to control stretch while for the older one more "more red" might be good for crispy buds.

So when settling at 600-700 mA, what COB spectra to choose and which stars to add for the two flowering panels?
2x deep red, 1x royal blue and 1x 4500 XM-L2 U2 4C on one heatsink for the old lady while 1x deep red, 1x royal blue and 2x 4500 XM-L2 U2 4C for the girlies panel
or both the same:
1x deep red, 1x royal blue and 2x 4500 XM-L2 U2 4C
2x deep red, 1x royal blue and 1x 4500 XM-L2 U2 4C

I have no glue on how the spectra shall look like as I can´t find the basics from KNNA

Which 50V driver are you referring to?

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a)Your measuring of 1320605 from fasttech.com. The 20 watt works up to around 49 V with current drop to 600 mA, if i remember right. 50 Watt stops working when going over nominal voltage, I assume the 30 Watt as well...
b) Meanwell LPC-35-700 (85%), PLM-40-700 (89%) are both below 20$ in Europe
PLD-40-700B (87% only 220V input!)
Goobay SET CC 350-20, 56 V but only 350 mA

Any further findings will be posted in the sticky "Led how to power them" thread.

5- You can use very little light for a small mother....

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Sure, but I want to grow in limited space and strictly seperate vegetation and flowering. My idea is a vegetation area of around 8 x 13 inches where I can keep a mother, clone it and grow either the mother or a clone mainly horizontally to a size of lets say 8x8 and by that a limited height of 5-10 inches. Every 4 weeks, the 8x8 cannopy plant is moved into the 10x10 flowering area where mainly vertical growth takes place.
So how many W would you suggest? COB point source or a chain of stars on a larger area heatink for more uniform illumination ( whose length can btw be easily expanded or reduced, depending on the actual needed size of the grow area, but on the other hand we are talking on 5-10 W)

Shall I move with the mother/vegie panel to another thread, as it might be or get off topic?

Hi everyone, Here is the update on my purchase.

I have been refunded the amount I paid for the LED's.
I have emailed arrow about my order with no response?
It has been 3 days today no response.

Thats all I know right now.
Canna

CannaBare said:

Hi everyone, Here is the update on my purchase.

I have been refunded the amount I paid for the LED's.
I have emailed arrow about my order with no response?
It has been 3 days today no response.

Thats all I know right now.
Canna

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Well that's a buzz kill.

Anyone supplementing the 3000s with 660nm?

PF you are welcome to ask questions here, I am impressed how much you retained and put together in one cram session

I recently contacted CREE inquiring about LER data for the CXA3070 (maximum theoretical lumens/W for a given color temp curve). The LER allows us to estimate efficiency using lumen figures. They reported back that the CXA2540 3000K LER is 325 (very close to Mr Fluxs estimation of 328 ) and the 2700K is 321 which is a shocker to me, I expected it to be higher. So I plugged those numbers into the spreadsheet and the 2700K Z2 (top bin) comes out about .5% higher in terms of efficiency than the 3000K Z2 (mid bin).

Sorry I put the link to the page I was referring to but not the actual post. Here is a snapshot of your design using 1 CXA3070, 1 Luxeon ES royal blue and 3 Luxeon ES deep red on one string at 650mA. It will dissipate 29W at 43.7% efficiency and total vF will be about 44.75.


We do have a DIY vegging thread going that might answer your veg questions. You could add a switch to bypass a few of the LEDs when they are not needed. You could use a very cheap 300mA or 450mA driver that are reasonably efficient (70-80%) with 2 or more LEDs on the string and they are capable of powering 4-5 XM-L2s

Thanks for the update Cannabare.

PF if you are in Europe it might be easier for you to acquire the OslonSSL 3T hyper reds. The 3Ts are slightly more efficient than the Luxeon ES but if you can find the 4Ts they are currently the ultimate deep red.

PF I will retest the maximum vf of the fasttech 650mA and 900mA drivers and report back with their output on the other thread. I grabbed a bunch more and now that I have a pair of reliable multimeters it is 10 times faster to test their efficiency.

RedCarpetMatches said:

Well that's a buzz kill.

Anyone supplementing the 3000s with 660nm?

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Yes...the one 3070 3000k and 3050 2700k i have...i am supplementing with 5w 660nm LED's

Chronikool said:

Yes...the one 3070 3000k and 3050 2700k i have...i am supplementing with 5w 660nm LED's

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That's a ton of deep red! You have a journal. Curious to see how that works out for ya.

SupraSPL said:

CXA3070 3000K Z2 bin just sold out on digikey

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Im glad I committed and ended up ordering one yesterday. Must have got one of the last ones.

Bueno Time said:

Im glad I committed and ended up ordering one yesterday. Must have got one of the last ones.

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Lol.....actually I grabbed the last 4 of the Z2s for my 200w 3070 + 315w CMH grow.....I knew there would be a bit of a rush to get the last ones so i jumped.....sorry to those that missed out.

Better luck next time! You never know - the CXA3590 may become available in that time which would certainly be silver lining...

I ordered from Arrow a few days ago, couldn't pass up the savings on 20. Spoke with a rep who didn't have any dates for the 3590...argh! Got a 11'x21' space to fill.

Man this thread is moving; I hadn't looked in a few days and had to read like 6-7 pages - it was OK though ... I was sad to hear about digikey and Canna's 2700k order but on the bright side at least I can save up some money for the next order. I just wanted to give a status update on my experiment with 4 3070s I've got everything working but I've had some issues with the fans - I think I blew them out with too many amps they are rated at .25mA and the wall wart I had them hooked up to were 12v 850mA; I think I just need to throw a resistor in there.

Supra what kind of thermal tape are you using? the thermal paste and electrical tape just don't cut it.

Here is a picture of the drivers:

I like these drivers because they have a volt adjustment so they are rated 48v/1.25A but I adjusted them all the way down and I'm getting 36v/860mA; this will give me a chance to play with the volts. I also like that it has connections for two leds and slides onto a din rail.

I still have tons to do before I will have a setup that I will feel comfortable flowering with but that is OK though

Thanks again to Supra and his dedication to this thread.

RedCarpetMatches said:

That's a ton of deep red! You have a journal. Curious to see how that works out for ya.

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Yeah guess you could call it a journal....here is my latest setup.... https://www.rollitup.org/led-other-lighting/794758-chronikool-crytochrome-all-conquering-cree-7.html#post10308167

Organix420 said:

Man this thread is moving; I hadn't looked in a few days and had to read like 6-7 pages - it was OK though ... I was sad to hear about digikey and Canna's 2700k order but on the bright side at least I can save up some money for the next order. I just wanted to give a status update on my experiment with 4 3070s I've got everything working but I've had some issues with the fans - I think I blew them out with too many amps they are rated at .25mA and the wall wart I had them hooked up to were 12v 850mA; I think I just need to throw a resistor in there.
View attachment 3034272
Supra what kind of thermal tape are you using? the thermal paste and electrical tape just don't cut it.

Here is a picture of the drivers:
View attachment 3034275
I like these drivers because they have a volt adjustment so they are rated 48v/1.25A but I adjusted them all the way down and I'm getting 36v/860mA; this will give me a chance to play with the volts. I also like that it has connections for two leds and slides onto a din rail.

I still have tons to do before I will have a setup that I will feel comfortable flowering with but that is OK though

Thanks again to Supra and his dedication to this thread.

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Really like your setup Organix! You should start a thread. I really like the cpu coolers. Cpu cooler manufacturers are inadvertent evil geniuses.

I was thinking just last night about going all in on a DIY with [10x] CXA modules. All built on cpu coolers bought in bulk from Ebay. The older P4, Dual Core and Xeon's are cheap and so damn practical. Love seeing your setup, gotta get er done.

About the fan....Voltage is most likely the culprit, even though your power supply can "deliver" up to 850 ma, the fans will only draw what they are rated to draw @ the correct voltage. The problem with wall warts is that they aren't all regulated and voltage usually rises with a reduced load. I would bet that is is being over-volted.

Nice setup organix! I like the adjustability and spread. I am curious about how the driver works. Are the CXAs in parallel and sharing that 860mA or is there two completely separate outputs? So if they are sharing the 860mA the drivers will be consuming about 35W each and that would mean your CXAs are running at about 430mA.

Also, the voltage adjustment range on the specs says 48V-56V, so it must be more flexible than the specs are letting on or it is operating outside the specified voltage range.

Regarding the wall wort. Were you running (4) .250mA fans on (1) 850mA PSU? If I understand correctly, it is best not to go above 80% max load and to make matters worse it seems like some wall worts lie about their capabilities. I have noticed that on cell phone chargers. If would recommend a 12V 2A switching PSU like this for $5.19, which is adjustable from 8.4-12V. Or this one if you want 9V and US shipping. Both of those have good efficiency 75-80%.

Good luck with yr grow can't wait to see the nugs

The CXA3070's just arrived however the ones received are not Z2 but rather Z4. Should I return or keep? Seems I got a free upgrade however is't the Z2 more efficient?

Nice score Westnewton! The CXA3070 3000K Z4 is the cheapest and most efficient growing LED ever put on the market. It may be more suitable for our purposes than the CXA3590 because the 3070 can spread it better.

For example if I run the CXA3070 at 900mA it is 43.7% efficient and cost $1.03/W. The CXA3590 at .7A is 42.3% efficient and cost $1.12/W. So at the value point, the 3590 will dissipate more wattage per LED (50W vs 32W) but it is slightly less efficient and cost slightly more.

Thanks Abiqua, I wanted to get heatsinks like Supra (more space to work with when mounting the leds) but they can get pretty pricey so I thought the cpu heatsinks would be the next best option plus it will be easier to play with distance between leds. If I were you I would get a couple 3070s and start playing with attaching them, powering them and work out some of the kinks before going all in with 10 or more.

Supra, you are right about the spec sheet I'm going to have to do some more testing tonight but the 36v @ 860mA reading came from a multimeter hooked to one of the outputs on one of the drivers. Also, I've been having trouble getting the 3070s to stay attached to the heatsinks what kind of tape are you using?