Introducing CobKits.com - specializing in DIY and Citizen COBs

MrTwist1

Well-Known Member
I'm interested in buying this light, the 3618... could you give me a parts breakdown of a package, including driver? I have a 20" x 17" x 42"grow box... so that's 2.65sq/ft and quite limited with height at 3.5'. I'm terrible with DIY and just want to hang one big light. Do you think it would work in my space? What amp would you recommend running the driver? Obviously I want as much light as the space will allow.
For such a small space you should consider running a bunch of smaller chips at low current rather than a big chip like the 3618... you will have the plants very close to the light so you want to spread the light and heat around the space more. The 1212s would seem like a good option for your space... maybe 4 or 5 of them at around 25W each or 700mA.

I know you say you're terrible at DIY, but I can tell you it's not easy flowering in 3.5' vertical space under high powered cobs... that 3618 will need more than 12" clearance from the canopy, and even more if you want decent coverage of your space. My 2 cents
 

CobKits

Well-Known Member
built this 4-banger today
CLU1825 3500k 80cri
140 x 80 pinfin
hlg320h-1400b

71W/cob w/dimmer maxed
gonna add a toggle to open dimmer leads to get to 74W ea
pinfins are pretty cool, 45C with my ir thermometer.

just bjbs on there, no provision for reflectors ill try to take some 3x3 tent measurements.

i feel like after my 5th or 6th one i know what i want in the rack. im gonna reduce the 4 banger from 24x24" to 21x21", eliminate those two center rails, flip the inner rails holding the heatsinks around and that will be my driver shelf. maybe 2 more passes before i go to the metal shop and say "ok make me 100 of these rails"

by keeping it as simple as possible and reducing material i hope to make it an affordable bolt-together project for anybody. Were approaching $1/watt at high efficiency in kit form thats a goal for me
FWIW that was a very consistent 650-700 umol over the 3x3 tent at 18".no hotspots. love the spread of the bjbs only. 21" frame size woulda been better for the tent, they are a little close to the walls

They like the movement but not the heat. When your ambient is 87f the air is kinda hot... hence the original question.

the only thing i could say is have a strong draft of cool air upwards to counteract. otherwise pinfins with exhaust right on top of them. at a given wattage they will produce a fixed amount of heat so regardless of which heatsink you use, sounds like its still all about heat removal
 

MrTwist1

Well-Known Member
the only thing i could say is have a strong draft of cool air upwards to counteract. otherwise pinfins with exhaust right on top of them. at a given wattage they will produce a fixed amount of heat so regardless of which heatsink you use, sounds like its still all about heat removal
Yeah the air intakes are at the bottom and outtake at the top above the COBs. It is designed to flow upwards, so that one pesky fan is going against the flow. I extract the air outta that space pretty rapidly, but I would prefer if the air from that fan went up. Not much space at the bottom for a fan unfortunately.

Is the fan protected against reverse polarity or will I damage it by trying?
 

Evil-Mobo

Well-Known Member
Yeah the air intakes are at the bottom and outtake at the top above the COBs. It is designed to flow upwards, so that one pesky fan is going against the flow. I extract the air outta that space pretty rapidly, but I would prefer if the air from that fan went up. Not much space at the bottom for a fan unfortunately.

Is the fan protected against reverse polarity or will I damage it by trying?
Just flip the light bro lol :P
 

CobKits

Well-Known Member
-i dont stock em i make em to order. ive honestly never sold a 1212 light engine- theyre more amenable to passive designs i guess

driver selection depends on your overall system size, # of cobs, etc.

every driver on the site is dimmable (albeit some are on the driver and some are remote)
 

OLD MOTHER SATIVA

Well-Known Member
bobby..have you priced the Espen drivers?

sure thyeyhave 96 efficiency but the smaller ones that are 90% must be chaeap

have catalog but no prices
 

CobKits

Well-Known Member
never heard of them before now

im pretty into the meanwells - so bulletproof and every option you could ever want. sure you pay a little more but i consider them the backbone of the system so for now thats my go-to.

meanwell makes a bunch of affordable plastic case drivers as well.
 

sixstring2112

Well-Known Member
never heard of them before now

im pretty into the meanwells - so bulletproof and every option you could ever want. sure you pay a little more but i consider them the backbone of the system so for now thats my go-to.

meanwell makes a bunch of affordable plastic case drivers as well.
but what if the meanwells are not real,like knockoffs lmao. i kid i kid,im back bitchs,and bambie lives to eat another carrot (:
 

CobKits

Well-Known Member
got tired of looking at this 3x3 prototype frame so i made it a light

heres the universal frame with holes for 105, 120, and 140 mm heatsinks. this was sitting lonely in the corner with a few random sized heatsinks. pulled em off, adjusted the rails out to 140 and mounted 9 140mm pinfins. BJBs in parallel with 18-2 300V CLR2 wire (aka home depot t-stat wire- look for the CLM2/CMR2 marking!)

upload_2016-10-3_1-41-14.png

i just used wagos, im going to mount them on the wago222-500 clips that @itsmetobyt showed us yesterday. so i left a little slack

3 cobs per hlg-185h-48A driver, ~75W per cob. 3500k 90cri clu058-1825

upload_2016-10-3_1-45-11.png

not too bad, maybe 2-3 hrs total to mount the 9 heatsinks, mount 9 chips with paste, run all wires. the drivers will be remote so this is ready to hang, just going to cut up some 16 or 18 ga orange extension cords for the driver-to-cob wiring. tested it in the shop with the meter, every cob looks uniform, 1400-1600 umol @ 6" @ 900mA. have yet to see an issue with the parallel drivers, they work great in every build ive done or seen. even with teh slight differences in Vf per chip im seeing very uniform illumination. im thinking these heatsinks could withstand dropping a cob and the resulting 4.25A hitting the other 2 cobs (112W per cob). would be hot but not catastrophic.
upload_2016-10-3_1-46-35.png
 
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