DiY LED - Cree CXA3070

Sussy

Member
Okay thanks. I'm gonna see if I can get larger heatsinks (like your medium build) locally. I was looking at CPU coolers but unfortunately down under Id be looking at 110 AUD for 5 arctic 11's.
I'll change to the other drivers as well, wasn't sure about the other ones because they don't put much info up.
Thanks
 

nestor

Well-Known Member
Okay thanks. I'm gonna see if I can get larger heatsinks (like your medium build) locally. I was looking at CPU coolers but unfortunately down under Id be looking at 110 AUD for 5 arctic 11's.
I'll change to the other drivers as well, wasn't sure about the other ones because they don't put much info up.
Thanks
Check out your local computer shops. They may have a few heatsinks laying around from previous generation processors that no longer fit current CPU socket standards. In other words, useless chunks of metal with fans attached. Just be clear that you're looking for something from an obsolete socket. I was able to pick up 3 of them for $5 US. I have no doubt that if I'd offered $15 I could've walked out with a box of 10-15. The downside is you may end up with a smaller fan size which equals more noise.

EDIT: You may also have to remove mounting hardware. Nothing too difficult, but an extra step nonetheless.
 

Dloomis514

Well-Known Member
Check out your local computer shops. They may have a few heatsinks laying around from previous generation processors that no longer fit current CPU socket standards. In other words, useless chunks of metal with fans attached. Just be clear that you're looking for something from an obsolete socket. I was able to pick up 3 of them for $5 US. I have no doubt that if I'd offered $15 I could've walked out with a box of 10-15. The downside is you may end up with a smaller fan size which equals more noise.

EDIT: You may also have to remove mounting hardware. Nothing too difficult, but an extra step nonetheless.
I bet you could flip those heat sinks on ebay for a profit, with a well placed link on some growers boards, discount for RIUers for sure.
 

DonPetro

Well-Known Member
You can slowly veg short plants with as little as 1W/ft² or what I would consider vigorous growth with 10W/ft². If you have a dimmable setup you can get growth on command LOL.
Thats great news as i have 9 vero 10's just sittin there...begging to veg something.
 

nestor

Well-Known Member
I bet you could flip those heat sinks on ebay for a profit, with a well placed link on some growers boards, discount for RIUers for sure.
Nah. If I were to go back and pick them up it would be to make lights and sell them locally.
 

CellarDweller

Well-Known Member
Just a short note of thanks to all y'all asking "stupid" questions and the slightly fewer of you that are responding with respect, integrity and intelligence.

I know responding to a post almost 13 months ago is a trifle "faux pas", but when I read the line "I counted the pixels in MSpaint" I realised I was in good company. The only limits to my pedantry are how granular you can measure things and THAT sir......that was special :)

Yessr here are the updated numbers. The original numbers were estimated from the PDF but for the more accurate numbers I counted the pixels in MSpaint.
View attachment 2997461



Thankfully KNNA specified PAR WATTS when he have us the 15-20% number. When I mentioned 10% for the 3000K CCA3070 I got that number from Mr Flux's data:

CXA 3000K
Blue : 10% power, 8% flux
Red : 24% power, 27% flux

CXA 4000K
Blue : 19% power, 16% flux
Red : 17% power, 20% flux

CXA 5000K
Blue : 24% power, 20% flux
Red : 14% power, 17% flux


I have also used the counting boxes method for the 3000K XTEs and I arrived at 11% (different phosphor). For vegging the 4000K or 5000K could be very helpful. Unfortunately the 5000K from Digikey is the lowest bin. Where did you find them for $33?



Got all the wiring from elecdirect but still waiting on the drivers so I have been working on another pair of driver boards for 300W each. Last time I used 1/2" plywood and but it is much heavier than necessary. Home Depot was out of pegboard so I am using a 1/4" sheet of underlayment and it is much better. I just drilled holes and will zip the drivers to the board. Made some power terminals and zipped those on.

To polish the big sinks I start off with 80 grit on a palm sander. That does the majority of the work. Then I go to 220 until all the 80 grit scratches are out. Finally 600 with a 3M manual sanding block. When I was polishing them I would continue to 1000 1500 and 2000. Then I would use a pair of liquid compounds and finally aluminum polish. I decided that none of that was necessary and 600 grit should be a good value point. I agree that the aluminum polish leaves a residue. I was using alcohol to try and dissolve it afterward.

I also go to 600 grit on all of my aluminum stars. Every single one of them is a far cry from flat lol.
 

alef

Active Member
dear friends,

can someone advise on vero 29. heat sink is 40 degrees. but the temperature near led itself is 100-120. is it normal?
I assume that led generates the radiation but i am not sure about the critical level.
 

Positivity

Well-Known Member
I wouldn't worry about the temp coming off of the LES

Maybe try taking a reading off of the face of the heatsink next to the cob. And another reading directly behind....and maybe one more reading off the Tj test point.

All should read similarly in my experience..

If your 40* reading is off to the side away from the cob than you may need more heat sink mass, fins, or air power...

I think 80c is the max recommended running temp but at that level it'll heat up a small room quickly
 

SupraSPL

Well-Known Member
Yep I am with POS heatsink temp of 40C might benefit from some extra cooling. I shoot for a 32C and 28C is not too hard to reach in the veg room. I usually take the reading between the fins or on the hottest part of the heatsink face. You can click the light off and try to get an instantaneous reading from the face without the light interference. But 40C won't cause you any trouble, especially with Vero.
 

CellarDweller

Well-Known Member
So .....please forgive my ignorance*, but a quick question. (the background to the question is below, for those that can be bothered or are bored!)

Is there any reason, barring cost (therefore potential $ efficiency), for not using a "high-density" array, such as the CXA2590? I am thinking of a 4000K as a baseline colour temp and then supplementing with additional lights where/when required. (more on the design of those later).

The Background:

I am right at the very beginning of my journey, will start with a small garden, but I want to start "on the right road" so to speak. Not interested in learning via other growing media/light methods and then "transferring" that wisdom into a totally different approach.

My initial idea is to build a 1-up dimmable CXA2590 on a CPU cooler that can be suspended above a single grow pot. Highly likely I will use a reflector on the array, as well and jerry rig some mylar around the plant to provide reflected/diffuse light.

As I will take this from seedling to fruit, I am thinking of starting with a 4000K range, it has good blues, enough red and spread in the green/yellow and so should make a good veg option. CRI isn't special, but frankly, CRI is an exceptionally subjective and potentially b*llshit way of measuring light (happy to take that offline with anyone that wants to discuss and/or edumacate me).

This light can be hung from a frame directly above the plant. My aim is to measure variables and learn (soil temp/ambient temp/PPF/humidity/airflow etc) in the aim of moving onto a controlled environment on a larger scale. I will also be looking to use the dimmer and supplemental lights to to accurately replicate day/night cycles, with light intensity and "spectral quality" being manipulated. There are some interesting scientific studies on this and how plants respond to watering cycles vs light cycles.

Finally, though this is an MJ growing forum....I shan't be growing MJ (I'll be growing veg, like tomatoes). My dream is to finally and scientifically jam it down the collective throats of the southern mediterranean nations that indoor growing can and will one day surpass the quality of their "grown with emotion under the sun" product.

Yours in anticipation of an utter hosing for using this forum to debate the potential of growing veg........CellarDweller

*I think that will become my auto-signature until I'm about 80, then it'll become "please forgive me"!
 

alesh

Well-Known Member
So .....please forgive my ignorance*, but a quick question. (the background to the question is below, for those that can be bothered or are bored!)

Is there any reason, barring cost (therefore potential $ efficiency), for not using a "high-density" array, such as the CXA2590? I am thinking of a 4000K as a baseline colour temp and then supplementing with additional lights where/when required. (more on the design of those later).

The Background:

I am right at the very beginning of my journey, will start with a small garden, but I want to start "on the right road" so to speak. Not interested in learning via other growing media/light methods and then "transferring" that wisdom into a totally different approach.

My initial idea is to build a 1-up dimmable CXA2590 on a CPU cooler that can be suspended above a single grow pot. Highly likely I will use a reflector on the array, as well and jerry rig some mylar around the plant to provide reflected/diffuse light.

As I will take this from seedling to fruit, I am thinking of starting with a 4000K range, it has good blues, enough red and spread in the green/yellow and so should make a good veg option. CRI isn't special, but frankly, CRI is an exceptionally subjective and potentially b*llshit way of measuring light (happy to take that offline with anyone that wants to discuss and/or edumacate me).

This light can be hung from a frame directly above the plant. My aim is to measure variables and learn (soil temp/ambient temp/PPF/humidity/airflow etc) in the aim of moving onto a controlled environment on a larger scale. I will also be looking to use the dimmer and supplemental lights to to accurately replicate day/night cycles, with light intensity and "spectral quality" being manipulated. There are some interesting scientific studies on this and how plants respond to watering cycles vs light cycles.

Finally, though this is an MJ growing forum....I shan't be growing MJ (I'll be growing veg, like tomatoes). My dream is to finally and scientifically jam it down the collective throats of the southern mediterranean nations that indoor growing can and will one day surpass the quality of their "grown with emotion under the sun" product.

Yours in anticipation of an utter hosing for using this forum to debate the potential of growing veg........CellarDweller

*I think that will become my auto-signature until I'm about 80, then it'll become "please forgive me"!
I think the best answer would be: Is there any reason for using them over standard-density CXA/CXBs?
 

CellarDweller

Well-Known Member
They output more light in a smaller package, so with good heat dissipation, could be used in a more "flexible" set-up to drive light wherever required.

They also increase the options available on active CPU coolers as some of the more advanced options out there have quite limited footprints on the heatsink connection.

But I do like your "If not standard density, why not".......like Keep It Simple Stupid, only more polite :)
 

sforza

Well-Known Member
Glad someone understands the struggle... But At last... I have decided upon the vero29 due to price, efficiency, and a few grow logs that's showed there capabilities.

But supra if I use the ballasts you suggested from ebay above how would I go about dimming the entire system at once?

And for craps and giggles I bet you guys never thought you'd see a 960w cob lol, gaurntee to put a hole through your house to alert the cops Hahaha.

http://www.led-professional.com/products/leds_led_modules/flip-chip-opto-introduces-300-w-600-w-and-960-w-cob-leds

Six of those 990w COBs mounted on a good sized heat sink should crank out a nice amount of light.
 

alesh

Well-Known Member
They output more light in a smaller package, so with good heat dissipation, could be used in a more "flexible" set-up to drive light wherever required.

They also increase the options available on active CPU coolers as some of the more advanced options out there have quite limited footprints on the heatsink connection.

But I do like your "If not standard density, why not".......like Keep It Simple Stupid, only more polite :)
Ok, let's take an example. 2590 vs 2540.
CXA2590:
about $70
footprint 24mmx24mm
LES 19mm
viewing angle 115°
max power ~130W
min efficiency@Tc 50°C (3000K 80CRI Z4 bin)
34.0%@47.8W
32.2%@62.2W
29.8%@84.3
28.4%@99.1W
25.9%@129.3W

CXA2540:
about $40
footprint 24mmx24mm
LES 19mm
viewing angle 115°
max power ~85W
min efficiency@Tc 50°C (3000K 80CRI W2 bin)
47,6%@13.8W
43.6%@25.1W
38.0%@41.2W
32.2%@62.8W
27.3%@85.7W

Unless you want to run 2590 harder that ~60W (eff < 32%), 2540 is cheaper and better option in the same package.
 

CellarDweller

Well-Known Member
Ok, let's take an example. 2590 vs 2540.
CXA2590:
about $70
footprint 24mmx24mm
LES 19mm
viewing angle 115°
max power ~130W
min efficiency@Tc 50°C (3000K 80CRI Z4 bin)
34.0%@47.8W
32.2%@62.2W
29.8%@84.3
28.4%@99.1W
25.9%@129.3W

CXA2540:
about $40
footprint 24mmx24mm
LES 19mm
viewing angle 115°
max power ~85W
min efficiency@Tc 50°C (3000K 80CRI W2 bin)
47,6%@13.8W
43.6%@25.1W
38.0%@41.2W
32.2%@62.8W
27.3%@85.7W

Unless you want to run 2590 harder that ~60W (eff < 32%), 2540 is cheaper and better option in the same package.
Alesh, thanks for that.

So it seems a combo of 3000 / 5000 would get a good range of colours for a "hassle free" environment at good PPF levels / Watt.

Or would you ditch the 5000 and go with some specific Blue LEDs? I think the blue LEDs would need to be mounted around the plant rather than vertical as the light penetration would be pretty weak past about 12" below canopy (on a 3W LED like the XPE). Supra seems to think the 3000 + Blue is better (waaaaaay back when in this thread....still reading through it all).

On the driver, I would like to get a dimmable driver (not for use at the beginning, but "future proof") and though am thinking of running the COB at 1A, it would be good to be able to run a few extra colour LEDs off the same driver/fitting combo in the future. Any recommendations there?

The Arctic Cooler route looks cool on the COB, but what about those blue LEDs? Any thoughts on how to manage heat best there?
 

alesh

Well-Known Member
Alesh, thanks for that.

So it seems a combo of 3000 / 5000 would get a good range of colours for a "hassle free" environment at good PPF levels / Watt.

Or would you ditch the 5000 and go with some specific Blue LEDs? I think the blue LEDs would need to be mounted around the plant rather than vertical as the light penetration would be pretty weak past about 12" below canopy (on a 3W LED like the XPE). Supra seems to think the 3000 + Blue is better (waaaaaay back when in this thread....still reading through it all).

On the driver, I would like to get a dimmable driver (not for use at the beginning, but "future proof") and though am thinking of running the COB at 1A, it would be good to be able to run a few extra colour LEDs off the same driver/fitting combo in the future. Any recommendations there?

The Arctic Cooler route looks cool on the COB, but what about those blue LEDs? Any thoughts on how to manage heat best there?
I can advise you which LED to choose in terms of radiometric efficiency but I have no experience growing vegetables (outdoor carrot doesn't imho) and I really don't know which spectrum might your plants like the best.

Recent 5000-6500K Cree COBs are as efficient as blue LEDs and also cheaper and easier to work with. 5000K version contains about 27% of blue (380-499nm) light. If that's enough for your application, I wouldn't use blue LEDs.

For drivers I'd aim at Meanwell HLG-1xxH-Cxxx as they're reliable, dimmable, highly efficient and not that expensive.
 

CellarDweller

Well-Known Member
Danke Schön alesh :)

Tomatoes and Peppers are big into intensity, but regarding spectra, it's pretty consistent policy (blues for veg, reds for flower/fruit).

Loving the idea of the dimmers to operate a ratio of light on the day light mimicry .....just getting a friend to write me up some code for an Arduino controller - that can also send me SMS info on temp/humidity/lighting problems. Certainly overkill, but I am in this for the "perfection" angle and then with a view to sharing all of the findings for free online (I have a day job and don't want to profit from a hobby).

I haven't perfected the daylight spectra research yet, but based on my limited (100s of hours so far) research at the right lat/long for my experiment, I reckon the below would give a "finger in the air" stab at good mimicry. Happy to have someone tell me I am totally wrong (but only if you tell me why and where!).

The prospect of other people growing perfect consumable veg in their central city apartments and massively reducing the reliance on terrible intensive farming methods is probably a pipe dream.....but we're all smoking SOMETHING on here right ;)

For the daylight mimicry on a given day length (16 or 12)

upload_2015-3-3_15-40-7.png
 
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