DIY LED with COBs - small medium and large grows

SupraSPL · Jun 28, 2014

In a nutshell, Cree is the best there is IMO. I am a big fan of the Cree XM-L2 and the Cree CXA3070

Dawn Patrol · Jun 28, 2014

Awesome thread SupreSPL! Really great info here.

BeenBurned · Jun 29, 2014

SupraSPL said:
In a nutshell, Cree is the best there is IMO. I am a big fan of the Cree XM-L2 and the Cree CXA3070

It seems like they will be a bit more work?... building a board, yes??
Gotta luv the internet!!! Can u imagine R-n-D'n something as well as resourcing parts without it?!?! I think I am going to borrow a hand break and throw together a can...Did u make yours?
Thanx again for the thread n info Supra. BB

seaslug · Jun 29, 2014

Please, borrow a hand brake instead.

gilgamesh · Jul 27, 2014

that's some nice work you got going there

help me find a LEDs suitable for a a grow bucket similar to this. you said in your first post "12" length is good for (2) COBs and a 24" length is good for (4) COBs. You can cool it with a single 140mm fan to make a super efficient cooling combo"

can I use a 10 inch heatsink from heatsinkusa to run 2 COBS. what type of COBs do you recommend for vegging and flowering? you mentioned a few in your post forsure, Cree

what about your red and blue steveleds, how many do you recommend to string up for a 10 inch heatsink or whatever that will fit within a 5 gallon bucket lid.

keep in mind that ill be hooking up a 5050 SMD to get some side lighting around the middle of the bucket.

i can increase the height of the bucket by using spacers that are top sections of the bucket cut off

Ibaba · Jul 29, 2014

Hi - I have 3 options for a 100w d.i.y cob chip,

a) 7 band chip (660nm 630nm 600nm 470nm 730nm 380nm (48:21:2:10:11:6:2))
b) full spectrum phosphor chip (new tech)
c) 3000-3500k chip (very cheap)

what would be the best? also I notice that the d.i.y cobs in this thread are not using lenses, is it better to use lenses or not? thanks for the help.

more info can be found on aliexpress for these chips

SupraSPL · Jul 30, 2014

@gilgamesh I use the 10.08"X6" chunk for a pair of COBs but I run them at 700mA (~50W total) and use passive cooling. If you run them at 1.4A you could use the 140mm fan but it doesnt reach all the fins so I think the 5.88" profile is a better bet. For the bucket lid though, the 10.08" would be great. You ouwld not even need a fan if you are only running 50W on it. 50W/sq ft of modern COB is almost double the power that I use and recommend.

The steves LEDs royal blues are still the best, but Cree recently release its "photo red" deep red XPes and they are the best deep reds so far :) You can run a 3000K cob with a string of deep reds and royal blues surrounding it. The ratio does not need to be exact and it would depend on how hard you are running the COB.

@Ibaba I would advise against the Chinese LEDs and COBs. Their efficiency is much lower so they create much more heat and put less photons in the canopy. That causes you to have to spend a lot more on heatsinks and drivers to get the same job done. When it all comes down to it, the Cree COBs actually end up being cheaper and they save you on your electric/cooling bill on top of that. That said, if you want a prefab unit, I would suggest option C 3000K although honestly I think you would be better off with HPS in that case.

That is correct, no lenses or reflectors used. I keep the COBs as close to the canopy as possible so I do not have photons escaping out of sides and I get a great spread. Lenses/covers/glass/diffusers are wasteful because they penalize all the photons passing through, even the ones that are already heading in the correct direction. Reflectors on the other hand only penalize the photons that are heading in the wrong direction.

Toaster79 · Jul 30, 2014

So far the best blue LEDs come from Cree as royal blue with 450nm peak, but as far as those photo reds go, those are actually Luxeon dies in Cree package. Using high CRI COBs like Cree CXA series or Bridgelux ES series cover up pretty much entire light spectrum. There may only be some lack in blue and far red section, but that's really easy to compensate with individual 5w LEDs like royal blue XTE, XPG2, and lower wattage deep/far red Luxeons.

johnnyrotten · Jul 30, 2014

would COB's work in a small, limited height grow area? I have a veg and flower area, each of them is only 1.5'L x 1.5'W x 4'H...Would I use different COBS for veg and flower? I've got a Kessill H350 magenta for the flower section and CFLs for veg currently...

rick ratlin · Aug 3, 2014

@SupraSPL thanks for the thread! This is just what the doctor ordered. I'm gonna try to diy a few of these and hook em up to the ecoplus wall fans, using the fan itself to cool the heat sink. Most likely it will be one cob per fan. This way we've got a free light mover. These are just supplemental, as the garden is run by hps.

Also, I'm trimming down the size of the veg room, and I'm looking to replace my flouros that light the clones with led cobs. I've tried some led lighting from the big store lightbulbs to the fancy grow lights. These are usually too powerful for clones, and they have to be at least 18 inches above the clones. Do you have any recommendations for a diy led cob cloner light? I imagine I'd need very very low wattage led cobs around 5000k, but I'm lost as to what to get. There is about 12 inches of clearance on each clone shelf. Thanks again for sharing!

OPM · Aug 5, 2014

Ty for sharing you info

This is one of the best DIY threads I've run across. I really want to build some LED's. but lack the funding atm. However, I wanna run some ideas past you.

Making a 4'x4' light, full of heatsink, holes drilled underneath by the diodes, or cob's to move air up through the sinks, then going to a cone shape shell, with the same kinda 6' fan for a HID.
I know it would be a heavy light, but this light wont move but up n down.
Most likely 2000w+ fixture but should out perform and outlast any HID. Would look real clean, and I can move the heat where I want it. (outside, to another room, ect..)
My idea is to put the plants on a lazy-suzan, IMO, easier to move the pots, rather then the light. I'm working with a 12x25 room thats now divided to 2 12x12 rooms, why I want such big lights.

Toaster79 · Aug 5, 2014

Whatever you do, don't go cheap on those LEDs and drivers, otherwise you'll regret it too soon.

OPM · Aug 5, 2014

johnnyrotten said:
would COB's work in a small, limited height grow area? I have a veg and flower area, each of them is only 1.5'L x 1.5'W x 4'H...Would I use different COBS for veg and flower? I've got a Kessill H350 magenta for the flower section and CFLs for veg currently...

I can't comment on what cob's to use, but.... from what I understand, changing lighting, even from veg to flower, a few things ring out to me.
1: The leaves are made by the plant to use the light that's provided, so changing light the leaves wouldn't help the photosynthesis process.
2: The plant's would go into a form of shock and make flowering times longer.

IMO: Use the best of lighting for the entire life of the plant. but can add a little reds at a time when in flower stage. example: use 1000w MH and 1000w HPS for veg, 600w MH and 1400w HPS for flower. Same light, just diff wattage.

Not to say that these diodes or cobs wouldn't have the same kinda light tho, it would be fine if used the same manufacture of cobs.

Everyone grows diff, so my opinion is not rule.

dabs4life · Aug 15, 2014

thank you for this thread. ive been google stalking cob grow threads but havent seen this one. it is awesome and i really appreciate the sharing of info

OPM · Aug 15, 2014

Found a place you can make your own cobs for a nice fixture. BMLhorticulture, Spyder600. but on the site, you can diy cobs you want. I'm still looking into it. So far looks promising.

Napalm · Aug 28, 2014

Thanks for the info @SupraSPL I almost pulled the trigger on the mars2 lights and have narrowed it down to a xg190 or the Onyx bloom. Either one will go in a 3x3 but I would prefer a little more power so I do not need to upgrade anytime soon. I read on another forum earlier that you were making a light for someone. I would totally be down for a light from you as I learned a lot about leds from your threads among others.
Please let me know as soon you can.Im back east as well.

SupraSPL · Aug 31, 2014

rick ratlin said:
@SupraSPL Do you have any recommendations for a diy led cob cloner light? I imagine I'd need very very low wattage led cobs around 5000k, but I'm lost as to what to get. There is about 12 inches of clearance on each clone shelf. Thanks again for sharing!

You could use Cree XML2 U2 4500K for cloning. I use one in my cloning box running at 300mA (1W) and the box is good for up to 20 clones.
http://www.fasttech.com/products/1609/10003889/1574600
driver:
http://www.fasttech.com/products/1612/10002422/1178000

You can get 5000K 6000K and 7000K in the XML
http://www.fasttech.com/products/1609/10001903/1581104

@Napalm sorry i didnt get back to you sooner

SupraSPL · Aug 31, 2014

Sorry for lack of updates. First all-led batch came out 1.16g/W which is a huge improvement for me. Second batch turned out 1.17g/W. Third batch still drying but I am expecting 1.1g/W as a minimum. I am not growing big yielders and I don't put much care into canopy management since I run so many different varieties together. Also I am using experimental recycled organic soil so I expect the hydro growers with big bud could get much higher numbers. But I am blown away! Over 1 gr/W of top shelf is a dream come true I have no complaints. 12 ladies drying out from 611W.

SupraSPL · Aug 31, 2014

There were a lot of new flavors in that batch. The standout was TH Seeds Sage N Sour, amazing smell. Doughy smell with diesel fuel and very strong. The TH Seeds Darkstar continues to impress me and I got some of their Dawgstar fem beans to try out eventually.

I got 3 GSC X Chemdog D babies vegging up, thank you @logic . It will be a few months before they get vegged up to size and they will be running with some Gage Green Aspirare (King Louis XIII x Joseph)

OPM · Sep 2, 2014

I just picked up a bunch of 6k and 3k 100w cobs, drivers and heatsinks. I was planing on using an old square aluminum road sign for the plate. instead of making a bunch of one cob lights. I plan on using 25 in a 4x4sq, 9 of them being 6k, the rest 3k. then add reds later for flowers.

If anyone has a better way, plz input info. Ty

DIY LED with COBs - small medium and large grows

DIY LED with COBs - small medium and large grows

SupraSPL

Dawn Patrol

BeenBurned

seaslug

gilgamesh

Ibaba

SupraSPL

Toaster79

johnnyrotten

rick ratlin

Perpetual Farmer

OPM

Toaster79

OPM

dabs4life

OPM

Napalm

SupraSPL

SupraSPL

SupraSPL

OPM

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