DiY LED - Cree CXA3070

[Castaman]

So it's better using some kind of thermal gel instead of compound to prevent drying?

 

[Growmau5]

I think you answered your own question

That and the wires are stripped too much, with bare wire dangling over the raw heatsink. you might want to look at sealing up those wires on the next one: either strip the wire just slightly (1-2mm) and allow the heat from the soldering iron to melt the wire insulation a bit further during tinning, or seal everything up with silicon, hot glue or liquid electrical tape.

As far as thermal paste, Cooler Master "Ice Fusion" has never steered me wrong .

 

[PurpleBuz]

That and the wires are stripped too much, with bare wire dangling over the raw heatsink. you might want to look at sealing up those wires on the next one: either strip the wire just slightly (1-2mm) and allow the heat from the soldering iron to melt the wire insulation a bit further during tinning, or seal everything up with silicon, hot glue or liquid electrical tape.

As far as thermal paste, Cooler Master "Ice Fusion" has never steered me wrong .

I also find it easier and neater to use 22 gauge wire for the cob hookup

 

[WwW1962]

Heloo , just thanking you for all this great stuff man, i have a single 3070 going atm and building a
XLM 10w x20 skeleton low power veg light. anything better then the chinese drivers @ 1w ?
thanked on the THC farmer site, aweome awesome thread thank you man
WwW

 

[SupraSPL]

I can't explain this..two cobs, same environment, working fans...no lens.
One is damaged, i think it's temperature...
View attachment 3507199
When i dissasembled it i saw my thermal interface dry, so it's 101% overheating.
No one knows, how much degraded second cob but it doesn't look damaged and works well.

What kind of paste was it? From recent temp droop tests I am convinced that we do not need to use the very highest conductivity thermal paste. As long as the paste is thoroughly applied and there are no air gaps, they all seem to work well. That means we can aim for something cheap, easy to work with and long lasting. So I switched from PK3 to MX2 because it is less toxic/non toxic, cheaper and easy to work with in cold basements/workshops. MX4 is only a bit more, has even better conductivity but I have not tried applying it (MX4 comes stock on Alpine 11s). Both MX2 and MX4 claim 8 year longevity.

 

[Castaman]

What kind of paste was it? From recent temp droop tests I am convinced that we do not need to use the very highest conductivity thermal paste. As long as the paste is thoroughly applied and there are no air gaps, they all seem to work well. That means we can aim for something cheap, easy to work with and long lasting. So I switched from PK3 to MX2 because it is less toxic/non toxic, cheaper and easy to work with in cold basements/workshops. MX4 is only a bit more, has even better conductivity but I have not tried applying it (MX4 comes stock on Alpine 11s). Both MX2 and MX4 claim 8 year longevity.

http://www.aliexpress.com/item/Top-wpbsa-thermal-grease-9-8-thermal-paste-graphics-card-cpu-containing-silver-siliester-nano-silicon/939032028.html

 

[SomeGuy]

@SupraSPL. I remember a thread on dimming but can't find it now. Am I remembering right or just old? I have a 10k pot to run my hlg-185h-48b, I just need to know which prongs on the pot to use.

Building another bar. 6' long, six vero18. Almost done. Just cobs to mount and wire and the dimmer to do.

All parts I've had for many months. Lol

 

[SupraSPL]

haha ya its a 100K, simple hookup 2 pins:

 

[nevergoodenuf]

@SomeGuy- I really think your build is the way to go (running parallel), minus the Vero13. I like the Vero 29s. Have you noticed any of your COBs brighter than another? I haven't. Are you going to build your next light in series or parallel? Parallel, is so much easier. Chose the wattage you want, and add COBs until you are happy with the efficiency or add more as you can afford them. This gives us the option of the HLG 320-36 and the HLG 600-36. One driver and simple wiring. Sorry I keep pushing this subject, but I don't think it is necessary to play with 200+volts with 18g. and smaller wire. I haven't heard anyone have any troubles running in parallel.

 

[SomeGuy]

haha ya its a 100K, simple hookup 2 pins:
View attachment 3514736

Thanks man. Your right. Data sheet says 100k. Hopefully find one local. Lol. . This light is looking good though.

 

[SomeGuy]

@SomeGuy- I really think your build is the way to go (running parallel), minus the Vero13. I like the Vero 29s. Have you noticed any of your COBs brighter than another? I haven't. Are you going to build your next light in series or parallel? Parallel, is so much easier. Chose the wattage you want, and add COBs until you are happy with the efficiency or add more as you can afford them. This gives us the option of the HLG 320-36 and the HLG 600-36. One driver and simple wiring. Sorry I keep pushing this subject, but I don't think it is necessary to play with 200+volts with 18g. and smaller wire. I haven't heard anyone have any troubles running in parallel.

I'm not running them parallel man. 6 vero-18 in series. Not advised to run parallel. You should read the sheets put out by the engineers who designed the driver.

Also. I do not use 18g wire. It's 14g off the driver and I run the same gauge to the cobs and solder. Sorry if that was unclear before

 

[nevergoodenuf]

I have and I also have talk to Bridgelux's engineers. There is no safety risk, but there is a chance that the light output will not be perfectly even. I haven't been able to see a difference in any of my lights ( almost 2 years, with different configurations). In most cases, we are running are COBs at only 30%, we aren't running 4 at 95% each. If that was the case I would recommend it. I don't recommend jumping from COB to COB when wiring, but all equal length wires to the + and - of the driver.

 

[SomeGuy]

So much easier to run them in series. Single drivers are also an option and I've done that. I fail to see the benefit of running parallel given the possibility of uneven output though, even if not visibly a problem.

Plus... "No difference you can see"

Eyes can be receptive when measuring light output. Did you light meter each cob?

Do what ye will though. I follow pretty standard practice though with fixture builds of my own. Once built they need to work for a very long time.

 

[nevergoodenuf]

A while back I did test the forward voltage of the China made bridgelux COBs (not veros, square) and it was less than .05 of a volt between the 4, I think. I didn't check the Veros because the holders cover all contact points and I am to lazy to take apart my light. My next build I will check the Veros. I still have 2 cen-100-36s, just need more Veros and heatsink.

 

[ttystikk]

@SomeGuy- I really think your build is the way to go (running parallel), minus the Vero13. I like the Vero 29s. Have you noticed any of your COBs brighter than another? I haven't. Are you going to build your next light in series or parallel? Parallel, is so much easier. Chose the wattage you want, and add COBs until you are happy with the efficiency or add more as you can afford them. This gives us the option of the HLG 320-36 and the HLG 600-36. One driver and simple wiring. Sorry I keep pushing this subject, but I don't think it is necessary to play with 200+volts with 18g. and smaller wire. I haven't heard anyone have any troubles running in parallel.

I've been wondering about this. It's easy for high volts to carry a couple hundred watts, however.

 

[predman]

Hi All, i want to make my own led fixture.

Now i just found this thread. And as a complete Noob, it is kinda hard to understand 184 pages of "gibberish". English not being my native language is also not helping much!

Can someone help me with some good documentation about the principles of using led for marhihauna growing. I am a complete noob and want to learn!

I use a 1200 HPS fixture atm and want to switch to led! Where to start!

I am really in doubt if i should buy the Spyder 1200 from BML. It costs a lot of money, and is really a bit above my budget for now.

How can i build my own, with comparable results?!

Thanks in advance and regards!

 

[HockeyBeard]

Hi All, i want to make my own led fixture.

Now i just found this thread. And as a complete Noob, it is kinda hard to understand 184 pages of "gibberish". English not being my native language is also not helping much!

Can someone help me with some good documentation about the principles of using led for marhihauna growing. I am a complete noob and want to learn!

I use a 1200 HPS fixture atm and want to switch to led! Where to start!

I am really in doubt if i should buy the Spyder 1200 from BML. It costs a lot of money, and is really a bit above my budget for now.

How can i build my own, with comparable results?!

Thanks in advance and regards!

Hi there! Well, the principles are simple - Plants respond to light temperature, or spectrum. Make sure to hit the spectrum that triggers photosynthesis (chlorophyll a: ~430-440 and ~660-680 ; chlorophyll b: ~490 and ~650). There isn't much else to the principles, I don't think. Are the advantages what you seek?

Seeing as you found your way to this thread, most here would advise against a pre-made unit. What is your budget? The options discussed here are not the cheapest, but they are the means to achieve top efficiency in converting current draw to usable light while significantly reducing heat signature and power consumption.

 

[predman]

Hi there! Well, the principles are simple - Plants respond to light temperature, or spectrum. Make sure to hit the spectrum that triggers photosynthesis (chlorophyll a: ~430-440 and ~660-680 ; chlorophyll b: ~490 and ~650). There isn't much else to the principles, I don't think. Are the advantages what you seek?

Seeing as you found your way to this thread, most here would advise against a pre-made unit. What is your budget? The options discussed here are not the cheapest, but they are the means to achieve top efficiency in converting current draw to usable light while significantly reducing heat signature and power consumption.

Hi Hockeybeard! Thanks for your answer!

The advantages i seek over what i am using now (Gavita 1000watt / Dimlux 1000watt) is:

Less electricity costs
Less Heath
Better gram per watt



Why would most advise against a pre-made unit? My budget is in theorie that what the BML spyder 1200 costs! (2100 euro's / 2400 dollars) But oufcourse, one of the reason i want to build it myself is to reduce those costs.



My goal is to learn to build these things, and understand them.

 

[ttystikk]

Hi Hockeybeard! Thanks for your answer!

The advantages i seek over what i am using now (Gavita 1000watt / Dimlux 1000watt) is:

Less electricity costs
Less Heath
Better gram per watt



Why would most advise against a pre-made unit? My budget is in theorie that what the BML spyder 1200 costs! (2100 euro's / 2400 dollars) But oufcourse, one of the reason i want to build it myself is to reduce those costs.



My goal is to learn to build these things, and understand them.

Ok, so you should begin with the new style of chips, not widely available in prebuilt panels yet. COB LED chips look like white light because they're broad spectrum, unlike the blue, purple, and red colors seen in the past. Another difference it's that they run at much higher wattage. Some are capable of running over 100W on one cob chip!

But there's more! It turns out that if you run the chip at half or less of its highest rating, it runs much more efficiently and sheds much less heat. This is why you'll see lighting setups where chips are run at 25W or 50W. The catch- always a catch!- is that chips are expensive, so getting more to operate more efficiently costs more up front.

There is much more, this is just the part that interests me most and why I'm building just such a lighting system myself. Along with no doubt hundreds of other people out there, lol

 

[predman]

But there's more! It turns out that if you run the chip at half or less of its highest rating,

What do you mean by that? By rating.