Let's talk DIY lights


If my metric conversion is right off top of my head, that’s like 4”x1”x.375”. Not enough for cob even with a fan. It could literally cool a couple of watts even with a fan.


@dbrn32 thanks for that. It must be a different name brand that I saw. The ones I saw were a little smaller than that. I suppose it could have been a vero something…


You’re talking about the cob itself and not the heatsink right?

It could’ve been a vero 18 or vero 10 for sure. Or possibly a Cree or citizen. Here is a pic of a cxb3590 next to quarter and ideal holder for reference. There are smaller versions of those as well.


It seemed a just a tad smaller. I might try and take a sneaky pic just see. @dbrn32


No problem. It could be hard to identify from pic, but I’ll try


Ok I guess


@Covertgrower would you like to see a size comparison? I happen to have parts coming in for my new build. It’s amazing how much cooling is needed for such a small light. Lol


Thanks @Daddy that helps. If the numbers look right on Thursday I’ll be ordering a rapid LED kit, and I think that may be the exact heat sink that comes with it. What COB is that?


vero 29s and yes this is the heat sink they use (140mm)


What you got cookin over there??? :bulb::bulb::bulb::bulb:


@dbrn32 about 950 true watts lol, I will do a test grow probably starting next month.


Damn! So if you don’t mind that I bombard you with a few questions?

Which voltage cob and driver configuration did you decide to go with? Color temp and cri? And what are you thinking for cob spacing vs size room?


12 series D’s 8 in 3000k 90 cri and 4 in 4000k 80 cri. Im running 3 320 meanwell series b drivers with ext pots. I will be testing a 6 plant “pod” at 4x6’. but the fixture will be about 3 1/2 by 5’ (the plants will actually be about 3x5 area depending on how long i let them veg"


also if I need better coverage or feel i need better efficacy I can just add 1 cob to each string but watts will remain the same , correct?


Very nice! I’m familiar with that set up, at 2100 ma. I was pretty happy with the 3500k in 80 cri, I think your setup will be a little better producer. If you start a thread or anything please tag me so I can follow along.


I think if you went from series wiring to a series/ parallel wiring you can add some cobs. But I think you may have to add more than one.

You are going to wire 4 to each driver in series correct?


yes series at the start and series parallel if i choose to add cobs. I am kinda stuck at the 1kw mark because my controllers are 1kw x8. I will probably start a journal after the first of the year after I am already in veg. I will be trying several different things and the same time and fill everyone in.


I don’t remember what minimum voltage is, but I would assume you could do two strings of three cobs each running at 1050. If not, you can certainly do two strings of four cobs.


I figured out those numbers and lumens really dropped off. Im at 10k for the 90 and 12k for the 80 cri. at 2x4 at 1050 im at 40% of that. I am testing intensity on this run. I am thinking i will even be able to control node spacing with a twist of the nob…shhhh it’s a secret.


I don’t have the data sheet in front of me, but I’m thinking you may have made a mistake in your math. For 8 cobs anyway. 6 doesn’t fill the driver that way.

Running 4 at 2100 ma is whatever it is. But as soon as you cut the current, your efficacy will go up. Looking at a per cob basis, you will have more lumens per watt, just less Watts. But the overall wattage will still stay the same because you have double the cobs. So double the cobs and increase the efficacy of each cob should increase overall luminous flux.

Make sense?