Introducing CobKits.com - specializing in DIY and Citizen COBs

nfhiggs

Well-Known Member
Hmm, so many factors to consider. I did some light skimming on the strips vs cobs and the strips always cost more, but they have benefits too, but a lot is for like around 30 watts per square foot out of what I was researching, not quite sure what the minimum specs would have to be to veg without underpowering it, on led grower site a lot of the diy strip setups were hitting $500 for 4x4 coverage with 30w ft^2, ahhh my brain is melting, I hate to ask but could you help me out with the cheapest possible 4x4 veg light cuz I really want to go perpetual but I gotta get the tent and supplies in addition to the light so I'm tryna juggle all that, of course my grow is only 2 weeks in so I got over a month to line it up perfectly, my head is too full of cob diy from learning it all in a mad rush and rn I'm like :eyesmoke::dunce:
6 of the 44" single Samsung F strips - $168 from Digikey
1 Meanwell LRS-350-48 power supply (350 watts, 48 V) - $41 at Arrow
3 eight foot lengths of 3/4" aluminum channel - about $40 bucks at your local hardware store.
1 eight foot length of 3/4 aluminum angle - $10 bucks at your hardware store.
Thermal epoxy or thermal tape
Wire

Cut your channels to 46" for a one inch overlap on each end. Mount your strips about 8 inches apart (center to center), for a fixture size of 46"x40"

It'll be enough for vegging at 21W per square foot, and you can add 4 more strips and another 200W of power when you flip them to flower.
 
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Randomestguy

Well-Known Member
6 of the 44" single Samsung F strips - $168 from Digikey
1 Meanwell LRS-350-48 power supply (350 watts, 48 V) - $41 at Arrow
3 eight foot lengths of 3/4" aluminum channel - about $40 bucks at your local hardware store.
1 eight foot length of 3/4 aluminum angle - $10 bucks at your hardware store.
Thermal epoxy or thermal tape
Wire

Cut your channels to 46" for a one inch overlap on each end. Mount your strips about 8 inches apart (center to center), for a fixture size of 46"x40"

It'll be enough for vegging at 21W per square foot, and you can add 4 more strips and another 200W of power when you flip them to flower.
Thank you so much, I would've been just trying different strip and driver combos until I found the best price/wattage cuz the price goes up exponentially as more strips more wattage more money more driver capacity, you're a lifesaver man.(:
(Edit: since it's only for veg would the 5000k be better than 4000k? Dunno if it's true but there's the whole blue light for veg/tighter internodel structure plus in the product spec pdf the 5k had slightly better light per watt over 4k just barely. A lot of info says go for cool white in veg like 6500k cfls and t5s for example, but now I'm not sure what to think, any opinion on that?
 
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pop22

Well-Known Member
You can start with as few as 4 cobs and still have a good grow. I just completed a grow with 6 cobs running at a total of 270 watts. I pulled 348 grams dry. not too shabby I think.

Chazy Ice tent1- pic1 -3-7-2018.jpg


After drilling how to diy cobs I was told that strip leds, like Samsung f series for example provide much better coverage for a similar price dynamic if not less, you have any experience with them? I'm liking the idea but that wider spread has me thinking light penetration might not be as good, any insight on that?
 

Randomestguy

Well-Known Member
You can start with as few as 4 cobs and still have a good grow. I just completed a grow with 6 cobs running at a total of 270 watts. I pulled 348 grams dry. not too shabby I think.

View attachment 4122577
Ooh hot damn that's some good ass results, I may go for the strips cuz of that diagram that was posted, I got time to mull it over and learn the in and outs of strips, pretty sure I'll get it down inside of a week, after that I can weigh the pros and cons of each myself, money is really the deciding factor cuz it seems like both work very well, but I am leaning a bit towards the strips, thanks for the input!
 

nfhiggs

Well-Known Member
Thank you so much, I would've been just trying different strip and driver combos until I found the best price/wattage cuz the price goes up exponentially as more strips more wattage more money more driver capacity, you're a lifesaver man.(:
(Edit: since it's only for veg would the 5000k be better than 4000k? Dunno if it's true but there's the whole blue light for veg/tighter internodel structure plus in the product spec pdf the 5k had slightly better light per watt over 4k just barely. A lot of info says go for cool white in veg like 6500k cfls and t5s for example, but now I'm not sure what to think, any opinion on that?
I dunno, I grow under 3500K/4000K and I have no problem with the node spacing. I've never used the 5000K
 

Randomestguy

Well-Known Member
Just wondering, how much penetration can you really get from cobs/strips respectively, my current plans for an upgrade are too financially troubled but once I get a new job that's actually better than min wage things should change. thinking about a 5x9x8 LxWxH tent mixed hid and led but what I'm wondering on is height, with 8 feet of headroom that's 4 or 5 foot tall plants and I can't help but wonder about the lower vegetation, other than side lighting anyone know how far through a tree those lights will usefully go?
 

CobKits

Well-Known Member
Just wondering, how much penetration can you really get from cobs/strips respectively,
theres no one answer to that.

depends on relative intensity and spacing of emitters as well as distance from lights to top of canopy.

for example, 500W of cobs and 500W of boards/strips at teh top of a tent

lets say 9 cobs vs 9 boards to keep it simple. you could also use 9 strips spread out over the length of the tent as well

the spacing would be the same and both single diodes and cobs emit at similar angles, so say 18" down they would perform identically with respect to canopy and penetration

advantage of strips boards is the effective emitter surface is spread out a bit more, so if you want to you can get real close like with a T5.

considering youre mixing it up with HID id jsut use cobs, possibly with reflectors. they will throw light more similarly to your HID.

youre already going to want to be 18-24" or so from your HID so the advantage of strips/boards is kinda lost
 

Randomestguy

Well-Known Member
theres no one answer to that.

depends on relative intensity and spacing of emitters as well as distance from lights to top of canopy.

for example, 500W of cobs and 500W of boards/strips at teh top of a tent

lets say 9 cobs vs 9 boards to keep it simple. you could also use 9 strips spread out over the length of the tent as well

the spacing would be the same and both single diodes and cobs emit at similar angles, so say 18" down they would perform identically with respect to canopy and penetration

advantage of strips boards is the effective emitter surface is spread out a bit more, so if you want to you can get real close like with a T5.

considering youre mixing it up with HID id jsut use cobs, possibly with reflectors. they will throw light more similarly to your HID.

youre already going to want to be 18-24" or so from your HID so the advantage of strips/boards is kinda lost
Thanks man, it'd be sorta half and half as it's a rather large tent and that height allows for some real monsters so I really don't know if leds can get through that kind of canopy without the lower parts suffering, been looking around and quantum boards look pretty cool seems like a textbook t5 situation might arise from them tho. For that 5x5 ish area in the tent I'm planning, it seems like 16x citi cri 90 gen 6 1212 48 whatever 3000k might be pretty good for around 5x4-5 space, would you recommend the reflectors? With that much height I'd imagine all possible penetration would be needed dunno how well they work. Also do you run the site or just promote it cuz whenever I do get enough money I'd be building 2 lights one flower one veg so it'd be pretty cool if I could get a bulk deal being half and half for the 2 spectrums. Ps is gen 5 and 6 for citi cobs that big a deal? Seems the main difference is better temperature handling but when you're talking about that many 5 bucks really makes a difference on price.
 

CobKits

Well-Known Member
Thanks man, it'd be sorta half and half as it's a rather large tent and that height allows for some real monsters so I really don't know if leds can get through that kind of canopy without the lower parts suffering,
no reason they cant any different than any other light. if youve got shading you vot shading no light is boing to penetrate through solid leaf to foliage below. more points of light will help in any case

have you considered strips for side or intra-canopy lighting?

yes i do run the site, you can pm me or email is better

im getting down the the end of the gen 5s

gen6s are a few % more efficient.

people who use the gen5s buy a lot at that price and use more cobs run softer
 

Randomestguy

Well-Known Member
no reason they cant any different than any other light. if youve got shading you vot shading no light is boing to penetrate through solid leaf to foliage below. more points of light will help in any case

have you considered strips for side or intra-canopy lighting?

yes i do run the site, you can pm me or email is better

im getting down the the end of the gen 5s

gen6s are a few % more efficient.

people who use the gen5s buy a lot at that price and use more cobs run softer
Thanks for all the info and advice, not to mention new with leds, greenhorn all around. I'll definitely need to consider side lighting if I end up with some green giants. These plans are for when I get like 2k saved up so probably not tomorrow, I'll definitely hit you up about it closer to the date. I'd likely have the lights be very similar as spacing is almost identical so a mix and match of a 30 bulk pack half flowering half veg spectrum would be awesome. I failed my highschool engineering electrical portion lol but since I will need multiple drivers per light do they have to power separate systems like having 2 lights in one frame or can they be spliced together to power the whole thing? Sorry if that last bit is a stupid question
 

Randomestguy

Well-Known Member
they make all kinds of drivers in all sizes, you could have one driver running one fixture, multiple drivers running one fixture, or one driver running multiple fixtures
Gotcha, lol I was just doing a few quick short price gauges went with the largest size on cobkits which seems like 2 of the smaller size would work nicely
 

CobKits

Well-Known Member
cost per watt for drivers doesnt vary that much by size. little bit but not night and day

the larger drivers are a few % more efficient (say 96% for an hlg600 vs 93.5% for an hlg185)
 

mitch_buchanon

New Member
Hi,
I'm looking for advise, i got 4 Citizen CLU048-1212 90CRI GEN5 3000k and one 4000k (by the way, i'm trying to contact the seller for add another holder since i ordered just 4 by msitake and i got no luck), also got a driver MeanWell HLG-185H-C1400B Driver (Constant Current). My question is can i connect 5 of this cobs with this driver?. If yes, how many watts will consume each?.
And last question, will a heatsink rated for 35w max work without a fan with the 5 cobs working wiyh the driver that i mentioned?.
PS: Please let me know how to add another holder to my order since it is an international shipping order.
Thank you, have a great day.
 
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Randomestguy

Well-Known Member
Hi,
I'm looking for advise, i got 4 Citizen CLU048-1212 90CRI GEN5 3000k and one 4000k (by the way, i'm trying to contact the seller for add another holder since i ordered just 4 by msitake and i got no luck), also got a driver MeanWell HLG-185H-C1400B Driver (Constant Current). My question is can i connect 5 of this cobs with this driver?. If yes, how many watts will consume each?.
And last question, will a heatsink rated for 35w max work without a fan with the 5 cobs working wiyh the driver that i mentioned?.
PS: Please let me know how to add another holder to my order since it is an international shipping order.
Thank you, have a great day.
So just a bit of advice, if you don't know how to calculate wattage diy might not be for you unless you learn how to, it's voltagexamperage=wattage so you'll get a different wattage depending on the values you run it at. Voltage and current are your guidelines for the whole project not just watts.
 

mitch_buchanon

New Member
So just a bit of advice, if you don't know how to calculate wattage diy might not be for you unless you learn how to, it's voltagexamperage=wattage so you'll get a different wattage depending on the values you run it at. Voltage and current are your guidelines for the whole project not just watts.
Yes, i undestand that the part but i got a little confused with a few things. Can i run 5 1212 with that driver? .Or will the cobs turn on working at 40w?. Top driver = 143V / 5 = 28.6 * 1.4 = 40w. Are my maths ok?.
 

CobKits

Well-Known Member
no

cob will not run at 28.6 V

you need to pick a target current, look up the voltage from the datasheet (1212s are jsut over 36V at 1.4A)

then if you want to run 4 cobs you need 36X4
if you want to run 5 cobs you need 36X5

you have a little leeway but not much

for example 36X4 = 144V. if the driver give 143V that works. it may or may not dip the current output a bit.

but the absolute lowest you can run a 1212 is about 32V (and thats at a mere 0.1-0.2A).

under that they wont light up at all, and its questionable what the driver would do if youre trying to provide 1-1.4A at a voltage significantly under 36. (say 33-35.5V) they might flicker and never light up. better to have a little spare voltage than be right there

all that assumes series wiring with constant current drivers

you can read more here

https://www.rollitup.org/t/matching-drivers-and-cobs.883866/
 
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