Is it possible to build a good COB LED light for a grow tent 3x3x5 for under $200.00?

PicklesRus

Well-Known Member
Well I went a little crazy with the control panel. It is automated by an Arduino Uno; so I came in at around $360.00 for 385 watts. that is just under 50 watts per cob. I want to thank all of the posters to Rollitup.org who have contributed their knowledge and skill that helped me pull this together including but not limited to @Growmau5 and @bggrass Thank you:clap:
View attachment 3853742 View attachment 3853743 View attachment 3853744
what does the panel do
 

randydj

Well-Known Member
what does the panel do
Pickles:
I am using an Arduino Uno computer to control the COBs, Cob heatsink fans, the exhaust fan, the far red SemiLeds and the CO2 flow valve for my grow tent. Basically it turns the lights off/on along with the heatsink cooling fans on whatever schedule I want 12/12, 18/6, 20/4 starting at whatever time I want. example = turn the lights on at 2:00pm then off at 8:00am the next morning for an 18/6. Then during the lights on period I can turn off the exhaust fan and inject CO2 until the tent starts to get too warm from the lights then turn the exhaust back on and cool the tent back down. It repeats this cycle until 30 minutes or so prior to lights out. Then at lights out it turns on the 730nm (far red) LEDs for 15 minutes to take advantage of the phytochrome cycle putting the plants to sleep right away. The AC devices are controlled via the SSR-25-da solid state relays and the 12v dc devices are controlled via the small optically isolated relays in the lower middle of the cabinet. I know it seems like a waste of CO2 to run it like that but it is such a small tent (3x3x5) that I can run a complete grow on a 10# tank of CO2 @ a calculated 1500 PPM. So it only costs about $18 for gas.
 

randydj

Well-Known Member
Pickles:
I am using an Arduino Uno computer to control the COBs, Cob heatsink fans, the exhaust fan, the far red SemiLeds and the CO2 flow valve for my grow tent. Basically it turns the lights off/on along with the heatsink cooling fans on whatever schedule I want 12/12, 18/6, 20/4 starting at whatever time I want. example = turn the lights on at 2:00pm then off at 8:00am the next morning for an 18/6. Then during the lights on period I can turn off the exhaust fan and inject CO2 until the tent starts to get too warm from the lights then turn the exhaust back on and cool the tent back down. It repeats this cycle until 30 minutes or so prior to lights out. Then at lights out it turns on the 730nm (far red) LEDs for 15 minutes to take advantage of the phytochrome cycle putting the plants to sleep right away. The AC devices are controlled via the SSR-25-da solid state relays and the 12v dc devices are controlled via the small optically isolated relays in the lower middle of the cabinet. I know it seems like a waste of CO2 to run it like that but it is such a small tent (3x3x5) that I can run a complete grow on a 10# tank of CO2 @ a calculated 1500 PPM. So it only costs about $18 for gas.
I forgot to mention the dimmers for the cobs!
 

PicklesRus

Well-Known Member
I forgot to mention the dimmers for the cobs!
Wow nice! I have an arduino but wasn't sure what I would use it for yet.
I wanted to build a cabinet for fun but the project kind of was put on hold. I might pick it up again but I guess timers seem so easy to buy.
An arduino I guess would be cheaper to build instead of buying timers and stuff.

I should program my arduino for my new setup.
 

randydj

Well-Known Member
Wow nice! I have an arduino but wasn't sure what I would use it for yet.
I wanted to build a cabinet for fun but the project kind of was put on hold. I might pick it up again but I guess timers seem so easy to buy.
An arduino I guess would be cheaper to build instead of buying timers and stuff.

I should program my arduino for my new setup.
Pickles:
I went with the Arduino at first because I already had a couple and they are really cheap but since then I have come to respect the power they have. Basically they are only limited by my imagination and coding skills.
 

bassman999

Well-Known Member
Wow nice! I have an arduino but wasn't sure what I would use it for yet.
I wanted to build a cabinet for fun but the project kind of was put on hold. I might pick it up again but I guess timers seem so easy to buy.
An arduino I guess would be cheaper to build instead of buying timers and stuff.

I should program my arduino for my new setup.
Ive got no idea how to use Arduino, but the money savings makes me want to try to learn
 

mauricem00

Well-Known Member
if youre really on a budget,

15 2700K A19 bulbs, 15W ea = $75
5 5000K A19 bulbs, 15W ea = $25
20 outlet-to-socket adapters = $20
5 4 slot power strips = $20

300W bloom rig for $140
turn off half the 2700Ks for veg (or buy a few more 5000K)

not cobs but SMDs driven under a watt each and a 6 year old could put it together
seems like corn cob bulbs from E-BAY would be an even cheaper option. been using them to replace CFLs in my home and they work great and at 100 LPW with very uniform light distribution they are not bad.for a grow room mixing 2700k with CFLs may be an option
 

MeGaKiLlErMaN

Well-Known Member
seems like corn cob bulbs from E-BAY would be an even cheaper option. been using them to replace CFLs in my home and they work great and at 100 LPW with very uniform light distribution they are not bad.for a grow room mixing 2700k with CFLs may be an option
It's would work yes... But it also is not very efficient... And they will die out wayyyy faster. But if that's fine then yes it's an option. Just not one I would consider
 

pop22

Well-Known Member
I found a simple solution:

light engine pic2 -112-1-2016.jpg

I remote driver my mechatronics and I drilled and tapped a hole in teh top with a ring eyelet screwed in. works great. peace. I just hang it from teh ceiling or whatever i can hang from and a line thru the eyelet. I have four of these with 3590 36v 50w, warm, never hot, simple easy, cheap. peace
 

CobKits

Well-Known Member
seems like corn cob bulbs from E-BAY would be an even cheaper option. been using them to replace CFLs in my home and they work great and at 100 LPW with very uniform light distribution they are not bad.for a grow room mixing 2700k with CFLs may be an option
theyre fine for vertical. if used horizontal 60+% of your light is going in the wrong direction so you need a reflector. the A19 bulbs are all forward facing diodes
 

MMJ Dreaming 99

Well-Known Member
Man jerry's a good guy and he will hook you up... But I can't shake this trans guy from Thailand that ripped off his pants and yelled "hey guys my names Jerry!" And danced around... Ladyboys everywhere in Thailand... Be cautious if you ever go there lol
LOL! Maybe a little too weird though...
 

mauricem00

Well-Known Member
theyre fine for vertical. if used horizontal 60+% of your light is going in the wrong direction so you need a reflector. the A19 bulbs are all forward facing diodes
same with CFLs. a lot of people still grow with CFLs and using warm white corn cob lights in place off 3000k bulbs would be a cheap and easy way to improve spectrum and efficiency.some of the led light bulbs sold at home depot are only slightly more effiecient then CFLs.with a highly directional beam the LEDs would need to be much farther from the plant than the CFLs.this was a problem I encountered when playing with T5/LED hybrid lights
 
Top