I would love to take a crack at making some, seems as though its tricky to track down even cheap or otherwise. All the major manufactures make them but acquiring any less than 1000 has been a bit trying.
The closest thing I have seen is the US rapidled’ s cree’s
https://www.rapidled.com/leds/!Rapid LED CREEs|690x420
Even these a $5 a chip will not be cheap when you are thinking about min 8 to minimally cover a 4x4 area 
Very cool thread alot of information. I just purchased a diy 320 watt QB setup using the newer qb288 v2 boards with the added 660 nm red diodes. I’m have it wired it up and working I’m just trying to figure out to adjust it properly it has a io adjust on the driver and also a potentiometer . As a baseline I adjusted the driver to 75% of the range and kinda just guess on how much light I think I need using the potentiometer. Does this sound like I am somewhere in the ballpark on the best way to set my driver adjustment or should I just max it out on the driver and use the potentiometer. IDK this is my first LED light anything would be helpful just trying to figure out if I am on the right track.
Not sure if this applies or compatible with your setup.
For my small cob setup, added a dc meter inline with the potentiometer.
What sort of heatsinks are needed for the Cree’s?
Cheers
G
Yeah it’s the same thing you could use with a cob setup . It’s got a inline potentiometer already just curious on the best way to run it I’m not an electronic person at all so it’s hard for me to get my head around this stuff and how to talk about it and make sense. I guess from what I understood was run them as hard as you can while being able to control the heat that it puts off. With that being said I ran my light and this thing barely puts out much heat at all I can damn near touch it with my hands before it feels too hot. This is going to be crazy I’m putting 2 Oregon Huckleberry that are about 3 ft tall under it hear in the next couple hrs and run this thing 24 hrs for a couple days and see what happens.
@Sincy You’ll want to set the Io screw to the max value that you want say for your space or that is the normal max for your driver, and then adjust light output with the potentiometer.
Couple things that would help us, is what drivers do you have and how big is your space also your hang height from your plants cause then we could give you a good starting point.
TBH I don’t know but tend to think it would be based on the number and draw. I was thinking thermal paste on thicker gauge aluminum would likely wick the heat. You could also attach it to some generic aluminium heat sink from Amagoon I’d imagine.
Spec sheet here
The dimming can be done with resistance (potentiometer), 0-10VDC dimming, or PWM dimming. Three types of dimming in one package.
I didn’t pick it out but I like options on my toys. What does pwm stand for?
Pulsed Width Modulation.
Oh so they are flashing on and off real fast and you can control the pulse time on or off . Still learning thanks for helping
That’s how PWM works with typical diodes… however the driver interpreted the “on and off” flashes and adjusts the current. That’s why they are constant current drivers. 
No heatsink required.
That PCB will handle 6W with probably about a 10C temperature rise (worst case). A little airflow would be good but optional.
No worries
G
The nice thing about the AB version is you could mount the pot somewhere convenient.
Cheers
G
@Sincy odd you have the 48 driver but they can go up to 52ish v so it would work fine and will be maxing out the driver anyways cause of running three boards.
But yeah can max out the io screw if you wanted but you will probably only need to be using about 250-300w max for a 2x4 space, i fully expect that you will be able to run less depending on what you do for the walls and such, but id set it at around that level and then dim with your dimmer from there.
Cool I’m really impressed with how cool this thing runs even when it is maxed out. Very excited about this light and what it can do thinking about getting some far red strips to use for sunrise and sunset set but we’ll see. I have some white paint I was going to use on the inside and I might get some Mylar possibly that would be good but I am open to ideas. Thank you for the help @Mr.Sparkle.
Yes I need to get some sheet metal and make a recessed mount on the outside to minimize heat inside my cabinet. Plus I need somewhere to mount my potentiometer to need to look around for some aluminum sheet metal.
Sol-strips are using a cookie sheet. It is a great passive radiator. just push a little bit of air through there and it will surprise you.
Cheers
G
