DIY COB Questions & Future Build Thread

[Ghostfox]

Hello all and thanks for stopping in. I've been reading on do it yourself COB LED grow lights for the better part of two days now and have been trying to piece together exactly what to order for both a 4' x 8' flowering room and a 4' x 4' vegetative room. I'm looking to completely ditch my HID lights for high output LEDs in order to save money on electric as well as provide better light coverage. Initially I was going to pick up a bunch of Mars 300's but I'd recently read a thread where a fellow pulled ~1000g dry in a 4' x 8' running ~950w of Cree CXB590's and was inspired to build my own.

My plan is to build seven fixtures with four LED's each, five fixtures for flowering, two for vegetative. For the flowering LEDs 20 of these 100W 3000K eBay LED's, and for vegetative 8 of these 100W 6500K eBay LED's.

My main problem is figuring out how to provide power to these LEDs cheaply. I found a guide on Reddit that seemed to be much cheaper than using $13 50w LED drivers by using these 150w DC to DC Boosters until I got the part that told me I would need to get 7 of these 24V 15A Switching Power Supplies at $30 a piece. After poking around a bit more I found a variety of LED driver boards like these and am under the impression that they are the same as the $13 50w drivers mentioned by Supra here.

What I am primarily confused about is the difference between the 50w LED drivers in Supra's post and the board style ones I posted. Do I need switchable power supplies to run the ones Supra refers to or do I only need that for the method on Reddit? If not needed with drivers, what do I wire the drivers in to, a three prong?

I have no issues understanding the wiring on the fans or the wiring from board/boxed driver/boosters, just what's between the that and the wall outlet. Any insight is extremely helpful, and I thank you for taking the time to read and reply.

 

[Airwalker16]

Hello all and thanks for stopping in. I've been reading on do it yourself COB LED grow lights for the better part of two days now and have been trying to piece together exactly what to order for both a 4' x 8' flowering room and a 4' x 4' vegetative room. I'm looking to completely ditch my HID lights for high output LEDs in order to save money on electric as well as provide better light coverage. Initially I was going to pick up a bunch of Mars 300's but I'd recently read a thread where a fellow pulled ~1000g dry in a 4' x 8' running ~950w of Cree CXB590's and was inspired to build my own.

My plan is to build seven fixtures with four LED's each, five fixtures for flowering, two for vegetative. For the flowering LEDs 20 of these 100W 3000K eBay LED's, and for vegetative 8 of these 100W 6500K eBay LED's.

My main problem is figuring out how to provide power to these LEDs cheaply. I found a guide on Reddit that seemed to be much cheaper than using $13 50w LED drivers by using these 150w DC to DC Boosters until I got the part that told me I would need to get 7 of these 24V 15A Switching Power Supplies at $30 a piece. After poking around a bit more I found a variety of LED driver boards like these and am under the impression that they are the same as the $13 50w drivers mentioned by Supra here.

What I am primarily confused about is the difference between the 50w LED drivers in Supra's post and the board style ones I posted. Do I need switchable power supplies to run the ones Supra refers to or do I only need that for the method on Reddit? If not needed with drivers, what do I wire the drivers in to, a three prong?

I have no issues understanding the wiring on the fans or the wiring from board/boxed driver/boosters, just what's between the that and the wall outlet. Any insight is extremely helpful, and I thank you for taking the time to read and reply.

Man, don't buy those Chinese cobs. They burn out quickly, don't illuminate evenly, and are just overall crap. If you're worried about spending $$$, then buy Vero 18''s or Cree CXB2530's.

 

[Ghostfox]

Man, don't buy those Chinese cobs. They burn out quickly, don't illuminate evenly, and are just overall crap. If you're worried about spending $$$, then buy Vero 18''s or Cree CXB2530's.

I mean I can spend $16.25 per Cree 2530 or I could spend $26.33 for ten of the China LEDs. It would cost me $455 to run Cree as opposed to $79 China LEDs. This means I would have to have nearly 150 China LEDs burn out and be replaced to make even the cheaper Cree lights worth it. I'll stick with the China LEDs for now, although I do like Cree, will continue to use their products on my firearms and will likely build myself a Cree LED fixture in the future when I can afford Cree CXB3590's.

 

[J-Icky]

The vero 18s were down to $10 on digikey last I checked and they will run much more efficiently than those ebay chinese cobs. Honestly if you just want a cheap light I wouldn't waste my money on those ebay cobs and would just buy a few mars leds or just go with hps.

 

[Ghostfox]

According to the manufacturer the 100W China LEDs are 10,000 - 11,000 lumens each, so running at 50W that would be approximately 5,000 lumens each. So even with $10 Vero 18s at 4,000 lumens running at 50% for 2000 lumens it's still significantly cheaper to run China LEDs and replace them if they shit out. A four LED fixture with Veros would put out 8,000 lumens compared to 20,000 lumens with China LEDs that cost me the same as one Vero 18.

 

[Airwalker16]

According to the manufacturer the 100W China LEDs are 10,000 - 11,000 lumens each, so running at 50W that would be approximately 5,000 lumens each. So even with $10 Vero 18s at 4,000 lumens running at 50% for 2000 lumens it's still significantly cheaper to run China LEDs and replace them if they shit out. A four LED fixture with Veros would put out 8,000 lumens compared to 20,000 lumens with China LEDs that cost me the same as one Vero 18.

Go ahead man. You'll regret it when you're running them 12-18 hours a day for a month or two and they just keep shitting out. Also, when you see the individual filaments flickering and unevenly lighting up, you'll wish you hadn't sunk the money into themy and just went all out in the first place. If money's a problem, buy a mh/hps conversion ballast and just use that.

 

[grouch]

The Chinese chips will work fine. There are many ways to get the same result. Weighing your options and figuring out the best solution for your needs is part of the fun. His limiting factor is upfront cost so the solution is less costly cobs. If heat or electrical usage were the limiting factor it would be better to run more expensive higher efficiency cobs like cree and vero. Going the cheaper route also makes sense if cobs keep improving as fast as they are. Maybe replace them as better ones hit the market and the original is more than paid for.

 

[grouch]

Going cheap on the drivers may not pay off as much. The meanwells can run four to five cobs at 50w for about the same price as four or five $13 drivers. You would be able to have a better driver with dimming capability for about the same price and it would work well with future upgrades.

 

[Hampsteri]

I've used light with 200W worth of chinacobs and i think light what comes out of it is not as bright and intense as Cree or Bridgelux would offer. Bud is more airy etc... I would not go all-in with chinacobs.

 

[Abiqua]

How about just running 2x Vero's @ 100 watts apiece....

They are cheap, handle lots of current and still maintain HID level efficiency or tad better...

Might be slightly higher than 79, but damn sure cheaper than 400 +

 

[frica]

I mean I can spend $16.25 per Cree 2530 or I could spend $26.33 for ten of the China LEDs. It would cost me $455 to run Cree as opposed to $79 China LEDs. This means I would have to have nearly 150 China LEDs burn out and be replaced to make even the cheaper Cree lights worth it. I'll stick with the China LEDs for now, although I do like Cree, will continue to use their products on my firearms and will likely build myself a Cree LED fixture in the future when I can afford Cree CXB3590's.

Those Chinese leds have zero quality control besides them being a lot less efficient even if the Chinese claims are true.

Their ebay page says 9000 lm at 1000 watts but doesn't specify at which colour temp.
It's a lot less efficient than both Cree and Bridgelux cobs.

Any way, 10 of those Chink cobs for 26 dollar seems seriously fishy.
Sincerely doubt they'll be functional, probably some ebay scam

 

[deakus]

According to the manufacturer the 100W China LEDs are 10,000 - 11,000 lumens each, so running at 50W that would be approximately 5,000 lumens each. So even with $10 Vero 18s at 4,000 lumens running at 50% for 2000 lumens it's still significantly cheaper to run China LEDs and replace them if they shit out. A four LED fixture with Veros would put out 8,000 lumens compared to 20,000 lumens with China LEDs that cost me the same as one Vero 18.

Whilst im relatively a newbie with this, dont assume if you power them to 50w you get 5000 lumens-my understanding is around half of that 50w will be heat i.e. you would be lucky to get 2500 lumens.
I may well be wrong but with the branded products you will get better efficiency and longevity.

 

[grouch]

Whilst im relatively a newbie with this, dont assume if you power them to 50w you get 5000 lumens-my understanding is around half of that 50w will be heat i.e. you would be lucky to get 2500 lumens.
I may well be wrong but with the branded products you will get better efficiency and longevity.

Most cobs follow the same principle of becoming more efficient as the current decreases. If they did make 10,000 lumens at 100w they would probably make more than 5,000 at 50w.

 

[nevergoodenuf]

You are comparing 100 lumen per watt (maybe) against a COB that is easily 130+ lumen per watt or better. And these won't fail unless you do something wrong.

 

[nevergoodenuf]

100 watts of those cheap COBs may produce 30 or less par watts.
The same 100 watts of Cree or Veros will be 38 to 70 par watts at the same cost (of electricity.

 

[welight]

Let me give you Rileys led Laws of life

1. Good created Led and it was good
2. God created women and gave man an off switch for led and it was better
3. God choose not to create all leds equal
4. God gave man the forum so all his questions could be answered
5. God created the cheap led so the forums could be swamped with stories of the greatest buys on earth
6. when the rains came and the Cheap leds no longer worked, god laughed like a giddy child as the forums collapsed under the weight of questions WHY?

If you cant afford it then you have no choice but to find a solution, but the old adage is never truer than with led, the cost of a poor led choice is not the purchase price, its the hours spent trying to make it work or fix it
Cheers
Mark

 

[Ghostfox]

With everyone so concerned about the cheaper China LEDs, a few solutions come to mind.

I've reworked how I want to set it up. Four fixtures for flowering room with four LEDs each and I'll move the HID in there to the vegetative tent. This means I now need a total of 16 LEDs across four fixtures as opposed to 28 LEDs across seven fixtures.

I can buy 16 Vero's 18's at $10 a piece for a total of $170
I can buy 16 of these China LEDs recommended on Reddit at $6.69 a piece for a total of $107.04
I can buy 30 of the China LEDs in my original post for $78.99 which would allow me to replace each LED once.

After running costs and stuff regardless of which LEDs I go with the cheapest way for me to power them is with boosters and switched PSUs like mentioned in the Reddit guide. $37.06 per fixture compared to $60 with a Mean Well.

Build List for 1 Fixture:
$20.00 | (2) 3' x 1" x 2" Aluminum Channel
$ 3.53 | 150W DC/DC Booster
$29.99 | 110/220V DC to 24V AC 15A PSU
---- Choose One ----
$10.52 | Cheapest China LEDs
$26.76 | Certified China LEDs recommended on Reddit
$43.00 | Vero 18s BXRC-30E4000-F-23

Are the Vero 18s also 100W? The only information I can find on DigiKey is lumens per watt. If I need the same amount of Vero 18s to get the same wattage I would get from China LEDs I guess they're worth it. But they say 4000 lumens, which would mean only 2000 lumens each for a total of 32,000 lumens when my goal is 100,000+ on the canopy.

I haven't added fans or anything as I'd like to have the the aluminum and other materials in hand for measurements first. Basically I'll be using two aluminum channels per fixture, one on top and one on the bottom. On the back I'll hinge them together and on the front I'll use clips like you would find on a tool box or certain mason jars.

Using channels with hinges and clips is essentially like using a 2" x 2" aluminum square pipe but with the added advantage of being able to open it up whenever you want with ease. This means no externally mounted boosters. I can mount them inside of the pseudo square tube as well as hide all of the wiring in there. The only wires coming out of each fixture are the two coming out of the bottom of the tube to each LED and the 18g wire coming from the top of the tube and out of the grow room to the PSU.

From here I have yet to decide whether I should just put 40-50mm fans on each open side of the fixture or use 2" square plastic end caps that I drill a 2" circle in with a flange fed through for 2" ducting. Depends on what the temperatures get to, either option allows me to use CO2.

 

[Ghostfox]

Could I mount my LEDs inside of a grow hood on the top effectively and just have two hoods in the room instead of 4 fixtures? It would be cheaper and much easier to air cool.

 

[Airwalker16]

Could I mount my LEDs inside of a grow hood on the top effectively and just have two hoods in the room instead of 4 fixtures? It would be cheaper and much easier to air cool.

As long as they're on a heatsink. Check out neverGoodenufs high powered thread. It'll be on the first or second page. He's done a great job at it.

 

[Ghostfox]

All I need to know at this point is if this board is the same as this Mean Well. Obviously one is 50W and one is 60W but do they perform the same function?