Cheapest High Quality/Efficiency COB build?

cogitech

cogitech

Well-Known Member
For someone who is very handy with a soldering iron, electronics/electrical, etc. what are the best DIY COB builds for the lowest overall price?

In other words, I am much more willing to do the work myself (I would enjoy it, in fact) and save a bunch of money than have pre-assembled or pre-packaged kits and pay a premium.

Is there a way to source high-quality parts and DIY the whole thing from scratch? Are the savings worth it?

(I am currently on my first grow with a blurple but I expect I will want to upgrade at some point and want the best bang for buck I can get.)
 
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Krytend

Krytend

Well-Known Member
I went with cobkits.com Citizen 1212 are going to be your best option for a budget build. Or look into Samsung or EB strips if your not set on COBs.
 
cogitech

cogitech

Well-Known Member
Krytend said:
I went with cobkits.com Citizen 1212 are going to be your best option for a budget build. Or look into Samsung or EB strips if your not set on COBs.
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I'm not set on COBs or QBs. If there is a way to reduce cost and maintain quality/efficiency by doing more of the work myself, that's what I will go for.

One thing I didn't mention - I'm not in the States, so the vendor(s) would have to be those who ship outside USA.
 
nfhiggs

nfhiggs

Well-Known Member
cogitech said:
For someone who is very handy with a soldering iron, electronics/electrical, etc. what are the best DIY COB builds for the lowest overall price?

In other words, I am much more willing to do the work myself (I would enjoy it, in fact) and save a bunch of money than have pre-assembled or pre-packaged kits and pay a premium.

Is there a way to source high-quality parts and DIY the whole thing from scratch? Are the savings worth it?

(I am currently on my first grow with a blurple but I expect I will want to upgrade at some point and want the best bang for buck I can get.)
Click to expand...
If you want the best bang for the buck you can get, in terms of efficiency, then forget COB's and look at Samsung F-Series strips, or Bridgelux EB Gen 2 strips.
 
cogitech

cogitech

Well-Known Member
nfhiggs said:
If you want the best bang for the buck you can get, in terms of efficiency, then forget COB's and look at Samsung F-Series strips, or Bridgelux EB Gen 2 strips.
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Electricity is fairly affordable where I live, so I don't necessarily need "the ultimate" in efficiency. Any of the above-mentioned units will beat what I have by a big margin. I'm trying to strike a balance between upfront cost, complexity and efficiency, as I am sure many of you are.

Anyway, I just pulled the trigger on 5 Citizen 1212 3500k 90 CRI (ver. 6) and I plan to use the Meanwell HLG-185H-36A to drive them. All other components/materials such as heatsinks, TIM, wire, frame, etc. will come from my "junk" boxes of electronics stuff. The whole thing will cost me about $125 USD so I figure that's pretty good value.

Sorry to CobKits, but I found a vendor who ships for free. Couldn't justify spending an extra $45 USD for international shipping. It's not personal.
 
nfhiggs

nfhiggs

Well-Known Member
cogitech said:
Electricity is fairly affordable where I live, so I don't necessarily need "the ultimate" in efficiency. Any of the above-mentioned units will beat what I have by a big margin. I'm trying to strike a balance between upfront cost, complexity and efficiency, as I am sure many of you are.

Anyway, I just pulled the trigger on 5 Citizen 1212 3500k 90 CRI (ver. 6) and I plan to use the Meanwell HLG-185H-36A to drive them. All other components/materials such as heatsinks, TIM, wire, frame, etc. will come from my "junk" boxes of electronics stuff. The whole thing will cost me about $125 USD so I figure that's pretty good value.

Sorry to CobKits, but I found a vendor who ships for free. Couldn't justify spending an extra $45 USD for international shipping. It's not personal.
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TBH, you won't beat the upfront cost of a strip build. I just bought 12 Samsung 25W strips for a little over a $100. Another $50 for heatsinks and $25 for a power supply, and I'll have a 300W, 179 lm/W light for under $200.
 
skoomd

skoomd

Well-Known Member
nfhiggs said:
If you want the best bang for the buck you can get, in terms of efficiency, then forget COB's and look at Samsung F-Series strips, or Bridgelux EB Gen 2 strips.
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This!!!!!!!!!!!

Fuck COBs nowadays. The strips are cheaper, more efficient, provide muuuuch more even/uniform light, use a 3-5$ heatsink (vs. a cob using a $20-30 one....), and are just better in EVERY way.

COBs cause hotspots/bleaching, have worse penetration, cost way more, are hard to cool, and are just lame.
 
diyled

diyled

Well-Known Member
skoomd said:
This!!!!!!!!!!!

Fuck COBs nowadays. The strips are cheaper, more efficient, provide muuuuch more even/uniform light, use a 3-5$ heatsink (vs. a cob using a $20-30 one....), and are just better in EVERY way.

COBs cause hotspots/bleaching, have worse penetration, cost way more, are hard to cool, and are just lame.
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Which cobs were you using? sounds like you had them way to close.
 
skoomd

skoomd

Well-Known Member
diyled said:
Which cobs were you using? sounds like you had them way to close.
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I dont use cobs. Just an obervation ive made over the last couple years :)

Evenly distrubuted light is far less stressful to the plant. The plants will handle higher PPFD levels without bleaching/stressing. Assaulting the top layer of the canopy with a low number of high wattage COBs is bad. And running lots of COBs is not only very expensive, but still wont be as even as strips. Ive noticed people are hitting higher GPW with strips and QBs than COBs, and that's likely why.
 
diyled

diyled

Well-Known Member
They do the same thing for a similar price. They both have advantages over the other and it comes down to personal preference. Strips have 2 major disadvantages. The size of the strip and the limited choice of colours. Cobs have a high heatsink cost and need a little more height.
 
skoomd

skoomd

Well-Known Member
diyled said:
They do the same thing for a similar price. They both have advantages over the other and it comes down to personal preference. Strips have 2 major disadvantages. The size of the strip and the limited choice of colours. Cobs have a high heatsink cost and need a little more height.
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You're 100% right on the lack of color choices for strips. I want 90 cri strips! 2700k would be cool to see too.

But what do you mean about the size of the strip being a disadvantage? I think the whole appeal, and why strips provide great uniformity, is their form factor. You can do a lot with thin, long strips of LEDs. Pretty much any size space, or any crazy idea (like that one LED strip cloak light someone made on here) can be accomidated. The strips are about the same power as any COB (1-200 watts a strip) but since they're so long and thin, you can easily get a really even light coverage and much better penetration into the canopy than with COBs.

This is a PPFD map of my 10x strip 22" single row F series 320w light in a 3x3 tent at 18". Total cost was $400. If this was say a 2x4' tent, the strips would run wall to wall and be even better than this.





And this is a 20x COB CXB3590 light in a 4x4 at 24" (so considerably higher up) that cost in the neighborhood of $1500-2000.



The strips are much more uniform than even an insane COB build like that, even though those COBs were measured at 24" instead of the 18" for the strips. And since it's more diffused, canopy penetration is excellent.
 
CikaBika

CikaBika

Well-Known Member
I have 1m2 tent, And 360w of dimmed cobs inside..I wanna switch to f strips...Can somebody help.me up? And guide me? or link me with done products? plug and play type..
 
diyled

diyled

Well-Known Member
skoomd said:
You're 100% right on the lack of color choices for strips. I want 90 cri strips! 2700k would be cool to see too.

But what do you mean about the size of the strip being a disadvantage? I think the whole appeal, and why strips provide great uniformity, is their form factor. You can do a lot with thin, long strips of LEDs. Pretty much any size space, or any crazy idea (like that one LED strip cloak light someone made on here) can be accomidated. The strips are about the same power as any COB (1-200 watts a strip) but since they're so long and thin, you can easily get a really even light coverage and much better penetration into the canopy than with COBs.

This is a PPFD map of my 10x strip 22" single row F series 320w light in a 3x3 tent at 18". Total cost was $400. If this was say a 2x4' tent, the strips would run wall to wall and be even better than this.





And this is a 20x COB CXB3590 light in a 4x4 at 24" (so considerably higher up) that cost in the neighborhood of $1500-2000.



The strips are much more uniform than even an insane COB build like that, even though those COBs were measured at 24" instead of the 18" for the strips. And since it's more diffused, canopy penetration is excellent.
Click to expand...

Remember mate, we are growing plants here. Getting to know the genotype and having a constant enviroment will yield more than x PPFD vs y PPFD. A cob light or a strip light at the same efficacy will yield the same results in the hands of a good grower. It's personal preference based on which you consider has the advantages you want.

(:
 
skoomd

skoomd

Well-Known Member
CikaBika said:
I have 1m2 tent, And 360w of dimmed cobs inside..I wanna switch to f strips...Can somebody help.me up? And guide me? or link me with done products? plug and play type..
Click to expand...
Check my sig. Or go to ledgardener.com.

The f series build in my sig is 320 watts. im using in a 3x3 tent. Good PPFD, good PPF, efficient, and if you look at the PPFD map above it is unbelievably uniform and even.

You could squeeze things around a lil and do it for closer to $300. It wont be quite as nice though. Like using U frame instead of heatsinks, using the A version meanwell driver so u dont need to buy a dimmer, shaving off a strip or two and running the rest harder, stuff like that.
 
cogitech

cogitech

Well-Known Member
Thanks for all the input, people!

Regarding high heat sink cost for COBs; I'll be running my 5 1212s at ~37w each (36v x 1040mA). Efficiency will be approximately 50%, which means each COB will be radiating about 18.5 watts of heat. Even a basic (cheap) heat sink (when installed properly with good TIM) can handle 18.5 watts.

There's a local, old school (mom & pop) electronics shop nearby and they have "junk" bins of pulled parts. I remember seeing some massive heat sinks in there for ridiculously low prices. Might go dig through the bins.

Regarding light spread, I do believe there are multiple, simple ways to diffuse the light (if I experience any issues with hot spots).

I have some ideas rolling around in my head about using the COBs in combination with my "450w" (196w) blurple.

This is for a 20" x 36" x 5'2" tent.
 
skoomd

skoomd

Well-Known Member
cogitech said:
Thanks for all the input, people!

Regarding high heat sink cost for COBs; I'll be running my 5 1212s at ~37w each (36v x 1040mA). Efficiency will be approximately 50%, which means each COB will be radiating about 18.5 watts of heat. Even a basic (cheap) heat sink (when installed properly with good TIM) can handle 18.5 watts.

There's a local, old school (mom & pop) electronics shop nearby and they have "junk" bins of pulled parts. I remember seeing some massive heat sinks in there for ridiculously low prices. Might go dig through the bins.

Regarding light spread, I do believe there are multiple, simple ways to diffuse the light (if I experience any issues with hot spots).

I have some ideas rolling around in my head about using the COBs in combination with my "450w" (196w) blurple.

This is for a 20" x 36" x 5'2" tent.
Click to expand...
You'll be rocking it without the need for the blurple. You're already at 36 watts a sq foot with the COBs which is good. The blurples would be too much on top of that.

The only way to really diffuse an LED (without adding more LEDs) is with some kind of optic/cover over the light. A lense will diffuse the light, but no where near as good as a frosted acrylic cover would. The lense eats 5-10% of the photons, frosted acrylic/glass would be like 15-20% loss. If the loss was worth the diffusion gains in a reflective mylar tent using already fairly diffused light by having multiple light sources (it isnt) then everyone would be using diffusers on their LEDs. But say you have a parallel strip build: if you want more diffusion you simply slap another strip on the light. Strip costs $14 and heatsink $5.

This article explains the benefits of diffused light. And diffused light makes a biiiig difference in terms of photosynthetic efficiency and canopy penetration. I saw a photo of a guy that had 2 cobs @ 100w each in a small closest (maybe 2x4) and it was his veg room. Literally was completely shaded only a few inches below the canopy.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4559655/
 
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