LEDgardener

building cxm-22 10 cob lights in magnum hoods. Stole all my ideas from various people online.

You may be able to squeak by if you're running them really hard like you would be, but I think it'd be better to run more. It's tough to space 6 COBs in a 4x4 without ending up with uneven coverage.

Also, do you have a line on heat sinks that you could use to run COBs at 120W each?

I'd do what Maine Grower did and run 12 COBs at 50W each. Better efficiency and coverage, more expensive by a long shot though.

gotcha alright, thats what I was worried about. I'm going to be actively cooling the cobs no matter what I go with. Same design as the chilled/cob idea I was working on. Pin heatsinks sealed in my magnum hoods with an 8" vortex fan exhausting them. So the spacing I am working with is all the cobs going in a 26x32 area over the 4x4 space.

Still think 12 is the way to go? In which case id likely go with the cxm-22

Is the main idea behind running the COBs in the hoods to cool them with the fan?

yep, exhaust all the heat out of the room. Also, to reuse the 11 friggin magnum hoods I have. Would be such a waste just to toss them for angled aluminum frames. I just bought 30 cxm22 chips. 15 80 cri 15 90 cri. all 3k. I'm going to push them at 1400ma and I'm running 10 per hood. I got the 120mm pin heatsinks. I realize that is too small for passive cooling but i think running an 8" vortex per two hoods should cool them enough.

I COULD build the usual frame if you really think that will make a ton of difference. I see lights like timbers vero light and chilleds light are all a pretty small sized for a 4x4. My cobs being spread over the area of the Hoods face should be fine with 10 of em in there eh?

I’m sure those hoods will be just fine. This sounds like an awesome system!

Did you go with the Gen 3 CXMs? How many drivers?

yep gen 3. Im going to do 5 80 and 5 90 cri each hood. It seems like with the CXM especially, 90 cri is quite further into the reds than the 80 as opposed to like the citizen cobs, so i figured best to just mix em.

Im using a meanwell 480 and 320 per hood to run in series at 1400. I got the potentiometers for it. Rapid said I could hook both drivers to one dial to dim each hood so i hope that was correct.


I'll be posting pics of the build once the stuff gets here. I'm trying to think of something to use as the face to replace the glass on the hood. To hold all the lights and stuff. I can't do metal. I dont have the tools to cut holes in it really. I was actually considering using drywall. I could brace it with aluminum. Its pretty fire resistant, easy to cut holes in and cheap. I looked into like plexi glass and that would cost a ton it seems. Taking suggestions on that part if anyone has any ideas that arent too crazy expensive.

if they told you to get a 50k ohm pot then yes it will dim both.. 100k ohm is for a single driver...

could always use thin plywood or veneer like wood sheets.. if you have a hole saw, dremel tool, or any blade that can cut metal ( fine teeth over the huge wood teeth).. sheet metal used for tin knocking isn't to hard to cut holes in. 28-24 gauge range.. thicker than that it starts to get hard to cut without the right tools

One issue I can see is that these are 50+ volt COBs and running 6 of them in series on a 480 is likely going to exceed the max voltage rating of your COB holders and even your wire probably.

oh? i was planning to use 18 gauge wire. And i bought the cob holders cobkits suggests for them
http://cobkits.com/product/ideal-holder-for-clu048/
rated for 4amp 250v

18 guage has a 600v limit im reading no?



Thanks jolly, I was considering thin wood also, but i figured drywall for fare better if for some reason stuff got super hot and melted or something