Another 200W LED COB Build....

Im building my first 200W Cree LED COB bar.
Its going to basically be built the same as @Greengenes707 build with a few variants.
If you are looking to build a bar & haven't seen his 200W tutorial build -you should.

This is pretty much a personal test and will grow into a larger build if I like it and will be replacing my 2 -1K Watt HPS in the summer months (possibly year round if they give off decent heat but thats another project).
I am already working out plans for an adjustable bar setup in a complete frame that will house
(3) 4 COB bars in each frame & I would be building 2 frames total for a 6'x8'ish canopy.

The variants I mention begin with approx 2 feet of 1-1/4" x 1/16" thick aluminum bar stock.
I built a little "bridge" so to speak for my plugs and extension cord to be mounted to so they arent in contact with the fins of the heatsink. I slotted out 2 spots on the bridge for a ziptie to run through to hold everything securely to it.
The bridge will get mounted to the 2 outside edge fins with (2) 4-40 allen head screws on each side (not done yet in pics).


I also have added a little mounting plate for the potentiometer to be mounted directly to the fin of the unit.
It needs to be cut down and have a knob affixed to it but it is going to work perfect.
Every bit of wiring on this will have been soldered and heat shrinked when it gets completed except for the solderless connections of the COB holders.


As for the wiring of the cobs, I will be running the wire on the finned side of the heatsink to give the face of the light a clean look and have as much of the wire out of sight and as far from the main heat sources as possible.
Basically how it looks in this pic is about how it will look once the cobs are inserted and it is running. Maybe 1/8" of wire will be visible coming through to the solderless connectors on each side of the COB holders.



I'm thinking I should be firing this up in the next few days so I'll have more pics as soon as I get it going.
I will be sharing more ideas on this build but will wait til I have them at least underway or functional.

JUST A HEADS UP for anyone who is new to this like me, I would suggest grounding to the heatsink directly from the ground on the AC side. You will want to run a seperate lead from the green ground from the driver and affix it to your heatsink along with the AC male plug end that gets grounded at the outlet. As for the Meanwell driver itself, it will ground to the heatsink when it is mounted to it since it is a metal body driver. If you want to make sure there is good conductivity for a good ground, you can rough up the mounting points of both driver and heatsink with some 600 grit sandpaper before mounting. I had a bit of a time finding any answers on this subject regarding grounding so I figured I'd share what I have learned while looking for answers.

Quick update on my bar build.
I have it complete and running & man is this much brighter than I had anticipated. Videos or pictures do these lights no justice.
I have had it running for about 3 hrs now and this isnt even what I would consider "warm". Matter of fact, the "warmest part is on the ends of the heatsink, and the portion of the heatsink directly under the fan feels cooler than room temp to the touch.
There is no way I could run this in the winter with no heat during lights on like my HPS but this will surely work as an excellent summertime lighting choice. The fact that I will be using a fraction of the power for the equal light footprint and the added bonus of not needing the same A/C power consumption is something I eagerly anticipate.

Now that my "first build" jitters are over I can concentrate more on the frame idea I have for the remainder of the bars Im going to build.
Here's a pic of the bar completed with the wires hidden/soldered/heatshinked and ziptied out of the way.


Some may wonder why I used such bright zipties for this, and the answer is so I can visually see the mounting points to help provide perspective on how to "hide" some of the mounting points and give a cleaner appearance on future builds.
I plan to relocate the dimmer pot to the left of the driver (opposite of where its at now) and work out a bent aluminum mount for the fan.
I have more parts on order so I'll drop back and post once I make a little headway with the frame build and the other bars.

HydroRed said:

Quick update on my bar build.
I have it complete and running & man is this much brighter than I had anticipated. Videos or pictures do these lights no justice.
I have had it running for about 3 hrs now and this isnt even what I would consider "warm". Matter of fact, the "warmest part is on the ends of the heatsink, and the portion of the heatsink directly under the fan feels cooler than room temp to the touch.
There is no way I could run this in the winter with no heat during lights on like my HPS but this will surely work as an excellent summertime lighting choice. The fact that I will be using a fraction of the power for the equal light footprint and the added bonus of not needing the same A/C power consumption is something I eagerly anticipate.

Now that my "first build" jitters are over I can concentrate more on the frame idea I have for the remainder of the bars Im going to build.
Here's a pic of the bar completed with the wires hidden/soldered/heatshinked and ziptied out of the way.
View attachment 3656148 View attachment 3656150 View attachment 3656152

Some may wonder why I used such bright zipties for this, and the answer is so I can visually see the mounting points to help provide perspective on how to "hide" some of the mounting points and give a cleaner appearance on future builds.
I plan to relocate the dimmer pot to the left of the driver (opposite of where its at now) and work out a bent aluminum mount for the fan.
I have more parts on order so I'll drop back and post once I make a little headway with the frame build and the other bars.

Click to expand...

awesome light build, ya man those cobs are bright as hell

Thanks man! Im working on bar # 2 now so I'll surely be building the frame I have been planning. I got everything in except for the fan & driver but both have been ordered and should be here Monday. Gives me time to drill/tap the hell out of the heatsink haha

what type of light did you grow with before building the cobs?

(2) 1K watt HPS for flower room. Im only running 1 at the moment and just looking to replace the one for now until I get some grow time in with the led's. I'll have to keep the HPS for winter growing just because I rely on the heat they give off. It will be cheaper than using a heater & cob led combo. Smallest heater I have for my room would be 1500W and would need to be run when light are on and off when using the cob led's. Im happy with the results of the HPS, just no so much a fan of the utility bill that comes with using them...specially in the summer when I have to run a 12K btu A/C -yikes.

its going to be fun mixing and matching, i thought i remember you being a big bulb grower

have you thought about posting this thead over in the "indoor" " led" section, you would get allot of feedback from the led crowd,, its an impressive light you have built for sure

Thanks man! Means a lot being first one and all.
Start a new thread in that section you mean?

yes, put up your same pictures,, I felt lucky to find your thread over here in DIY,,, your light build is really cool and ther other led guys would give you props ,, ya man make a thread over there in LED

Ok, cool. I'll get another thread worked out and tag you in it once I get it set.

its nice to see a bulb grower try out the DIY cobs, the first time I flipped the switch on the cob light I built it shocked me fast just how freaky bright those little cobs are, and then putting 4 cxb's on a bar, I jokingly tell the wife we could play baseball at night in the backyard with these light bars,,, lol

Got 2 bars temporarily framed together while I fab up another frame to help me get an idea for spacing of the bars and the footprint once assembled. Dont wanna let the cat out of the bag yet, but this frame is going to kick ass. Just gotta take it from digital concept to reality. I'm 1 step closer.........

Red- If you get a CO2 controller and a tank and only run your fan system at lights out, you should be able to totally get away from HPS. I setup my room originally with fan/carbonfilter/intake on a temp/humidity controller. Eventually I added the tank and a ppm controller. Now when my tank is empty I just kick on the fans.

nevergoodenuf said:

Red- If you get a CO2 controller and a tank and only run your fan system at lights out, you should be able to totally get away from HPS. I setup my room originally with fan/carbonfilter/intake on a temp/humidity controller. Eventually I added the tank and a ppm controller. Now when my tank is empty I just kick on the fans.

Click to expand...

I hear ya, but I need the hps in the winter for sure. These led's dont put out nearly any heat at all so my winter time grows would need heat supplement & at 1500W for a tiny space heater it would negate the switch to LED's. Honestly though, if all I get out of the led's are summertime use at a fraction of the wattage used from HPS and A/C....Im completely satisfied with that. I did cO2 in a closed room for a while and dont miss it lol

So today I bought a digital laser thermometer to get some moderately accurate temp readings. I've had the light on for about 3 hrs now and will take more readings as the day goes on.

-From off/cool the initial temp readings on the heatsink were cooler than room temp @ 67.7*F across the heatsink.
-Within 3 hrs of run time with pots turned up all the way, I had temp readings on the ends of the heatsink (being the warmest section of HS) @ 81.3*F
-I ran the thermometer on the LED COB itself and got an average of 149*F

I'm unsure if the temps are going to go any higher since they seem to have leveled off at about the 1.5 hr mark and have been pretty consistent since.
I can't say I anticipate much more in regards to temp spikes from here on out.
If anyone has any info to share regarding temp experience with these lights, I would love to hear from you.

@sunni
I was wondering if you can bump this thread over to the LED section for me?
P.S. Congrats on the new addition to the family.

Here it is approx 10 hrs of run time & I checked temps again. After multiple readings, the "hottest" temp reading on the heatsink was 81.4*F and the "hottest" reading I got on the COB itself was 177.1*F.
This seems extremely cool for such intense lighting?
According to the manufacturer, I believe they test these to get their binning numbers at around 85*C (185*F) but run @1900ma.
This is VERY promising to me in regards to replacing my 1K HPS in the summer.
I'll also be taking the anticipated (3) bars pre frame down to (2) bars per frame. I havent done any lighting tests yet, but intensity doesn't seem to be an issue and I believe (2) frames with (4) bars total will be more than adequate for my space considering my headspace.

How much you got in those LEDs Red?

johnny961 said:

How much you got in those LEDs Red?

Click to expand...

Approx $750 or so for everything. I know I can get these figures down now that I've got enough wire/hardware/framing left over from the original build and I also get free shiiping on some items too which greatly reduces cost as well.
I ordered my Drivers from Jameco and they offer free shipping after your initial order. My next order for 2 will save me $25 alone on shipping (if purchased seperately). I also have stuff factored in that was initially purchased that I didn't use like Kapton Tape etc that would have brought my costs down.