DiY LED - Cree XPE XTE XML2 - Luxeon ES - Oslon SSL

[SupraSPL]

Figured it is about time to update the original thread. The total project will be 750 input watts. Actual LED dissipation will be about 600 watts. Total cost for materials was about $2500. The goal is to replace a pair of 600 HPS to reduce heat and increase yields a bit.

There is also 100 watts of LED for vegging. Surprisingly this is more than enough to veg for a 2400 watt flip flop HPS grow.

The heatsinks are from Heatsink USA and they are getting more expensive over time but still the cheapest I have found. I use passive cooling and shoot for a Tj of 50c so the heatsinks are huge (110cm2/watt). The drivers are from ebay and Fasttech, all 700mA. Leds were ordered from Cutter, Steve's LEDs, LEDgroupbuy, Fasttech and ISLED. Wiring, heatshrink tubing, slide connectors, fuses etc from Elecdirect.

This is the layout of one 50w module. Everything is running at ~700mA. Amazingly heatsink temp has been about 35c or less. Incoming air is 22C and canopy temp is 28C with a bare 600 HPS in the room.
(8 ) Cree XTE warm white R3 bin (32%)
(3) Luxeon ES deep blue M4R bin (55%)
(6) Cree XPE 630nm red P3 bin (42%)
(2) Luxeon ES deep red EX6 bin (38%)
(2) Luxeon ES deep red EX7 bin (38%)
(6) Oslon SSL deep red 3T bin (42%)



The reds are all on the same string and the white/blue is on its own string. So there are (2) drivers for each module (24) drivers total.

This design is already almost outdated since the XML2 have come around but they are only slight improvements so I will probably complete the project as is for now.

 

[SupraSPL]

I recently discovered how unflat heatsinks and LED stars are. Metal to metal contact is critical for heat transfer. If we mount an unflat star onto an unflat heatsink the layer of thermal paste will be thick or even worse there can be air in the gap. The consequence is a much higher thermal resistance which leads to a higher junction temp. Red and deep reds LEDs are badly affected by high junction temps because they lose efficiency very fast as the temp rises (droop). Whites and blues don't temp droop too badly but all LEDs lose brightness over time and this process is directly affected by junction temp, so longevity of the entire lamp is decreased.

Unfortunately it is a PITA to sand LED stars because it is possible to dislodge the LED dome. When you build DiY LED on a large scale it is very time consuming and the last thing we need is another time consuming step. But when it comes down to it, I am willing to do what is necessary to get the job done right. So I have been sanding them with 200 grit and then 600 grit. The heatsinks themselves have been fully lapped and polished.

This is a partially sanded LED star. Every aluminum LED star has this problem and every aluminum heatsink I have checked has needed work to be considered flat. The outside edges of the star are the only parts that touch down unless you work on them.

 

[smokey the cat]

This is a partially sanded LED star. Every aluminum LED star has this problem and every aluminum heatsink I have checked has needed work to be considered flat. The outside edges of the star are the only parts that touch down unless you work on them.

View attachment 2903211

No wonder you need 200grit to lap it. The only word out of my mouth seeing that pic:
[video=youtube;l1dnqKGuezo]http://www.youtube.com/watch?v=l1dnqKGuezo[/video]
This is a brilliant public service you've done here. Thank you.


Can I ask about your choice of Red emitters.

(2) Luxeon ES deep red EX6 bin (38%)
(2) Luxeon ES deep red EX7 bin (38%)
(6) Oslon SSL deep red 3T bin (42%)

Why the inclusion of Oslan here - why didn't you use Luxeon to cover 660nm? or are those the StevesLEDs 670s you're using?

 

[SupraSPL]

LMAO yes that word is exactly what I was saying when I thought about reworking the modules I had already assembled.

Yep the EX7 bin is Steve's LEDs 670nm. The Luxeon ES are cheaper than the Oslon and only slightly less efficient. I added the Oslon SSL80 to try and further spread the SPD and because I wanted to try out the 80 degree. Any of those deep red choices will do just fine on their own but if the SSL80 4T bin becomes available at a reasonable price it would trump them all (48% 700mA 50c)

 

[Positivity]

That's pretty close to the leds I've been running. I got the Philips ex6 bin, 47 of them running right now. So far the plants seem to like it. I have been thinking of mixing up the reds similarly in the future also, seems like a good idea to spread out the spectrum. I also got some Philips royal and cool blue to add into the next round.

whats up with the osion 4t bin? Can't find them anywhere..

 

[smokey the cat]

I added the Oslon SSL80 to try and further spread the SPD and because I wanted to try out the 80 degree. Any of those deep red choices will do just fine on their own but if the SSL80 4T bin becomes available at a reasonable price it would trump them all (48% 700mA 50c)

Damn, 48% with a tight beam seems fantastic.

80* spread does seem better for our uses than the typical 120*. Ideally we'd be calculating efficiency at the growth surface - I can see a scenario where a less efficient emitter with a tighter beam succesfully feeds more light into a grow than a more efficient emitter with a too-wide spread.

 

[SupraSPL]

(7) 5 gallon buckets. 250 watts LED. Emitters are running at about 2 watts each. Heatsinks are barely warm to the touch ~30c 85f.


Camera color corrected


There is a 600 HPS in the middle, waiting to kick it on. 10 days into flower.

Varieties in this batch
RP Kandy Kush
RP Holy Grail Kush
Reservoir SSSDH (Shire cut)
TGA Ace of Spaces

Have run them all many times. The Kandy Kush is as described. Trainwreck structure with strong OG funk.

All in recycled organic soil. Usual amendments but from strictly organic sources - homemade EWC, compost, chicken manure, indonesian guano, kelp meal, azomite, leonardite. They get 150ppm well water only, except a few doses of fish hydrolysate and blackstrap if I think they need it.

 

[SupraSPL]

Vegged up to ~3ft with LED. 2 weeks to clone, 3 weeks in 1.5L, 4 weeks in 14L (5 gal bucket) so basically 2 months vegging, 2 months flowering.

 

[Someacdude]

Im down, i almost bought some now im going to make them, thanks guys

 

[anomuumi]

Awesome project! So you use only thermal glue for attaching the stars? How much HID watts do you run per sqft?

 

[SupraSPL]

I used Prolimatech PK2 which is a thermal paste but it has no adhesive. It creates a vacuum effect under the star but I also use kapton tape to keep them in place. Probably not a marketable solution but it avoids drilling and does give the best heat transfer. PK3 is slightly better.

• Al 70~88(wt%)
• ZnO 15~27(wt%)
• Oil 11~19(wt%)
• Antioxidant 0.5~2(wt%)
• Adhesiveness: 250000Cps
• Thermal Conductivity: 10.2 W/m - Degree C
• Thermal Impedance (Resistance): 0.015 Degree C-in2/W
• Specific Gravity: 2.5g/cm3
• Features: Excellent long-term stability Not electrically conductive Non-corrosive Easy to apply and less to use No "burn-in" time required Low dry-out

 

[SupraSPL]

The room next to it has 600w HPS X 2 (bare). The canopy is maybe 3'X6' so approx 67W/sq ft. The HPS results are great but the LED bud gets more trichs, stinkier and more potent not to mention using less than half the electricity and heat.

 

[Someacdude]

As i said, led is the way i wanted to go, but price kept me from going that way with my first grow, Next time, im going to be ready. Thanks to everyone who helped .

 

[anomuumi]

Cool, I thought the kapton was there to insulate the contact points. Inspired by your thread I finally started my own build by wetsanding the heatsinks. Any tips for sanding the stars? The 10mm ones are a bitch to hold and I'm worried that the residual dust will cause problems. Should I wash them after sanding?

What brand are your drivers? I have some chinese cheapos, but I have second thoughts about using them..

 

[SupraSPL]

The stars are harder to sand one at a time because there isn't much to hold onto especially the 10mm. If you have a few still connected together you might be able to make it easier and save some time. I did the 20mm stars 2 or 3 at a time and just bent them so I could get one at a time. I was able to work on a whole sheet of 10mm stars and some 5 at a time.

I used a 3m palm sander from Lowes and worked in the sink wet sanding. It is no problem to rinse them off afterward. The aluminum makes sort of a pasty substance that can get on the domes but cleans off no problem.

 

[rememberingnever]

Awesome work again SupraSPL. I've been scouring posts and trying to locate various LED's but now i'm left with a huge list and wondering wtf to do . My brain hurts at the moment haha. I don't suppose we can post links on here can we? I'd like to collate the information i've gathered somewhere so someone with a more experienced eye could cast a look over it, point to better sources (for better binned solutions) and add to it if i've missed any important new chips... if not too much bother. Keep up the good work, will be subbing up for sure.

 

[SupraSPL]

What brand are your drivers? I have some chinese cheapos, but I have second thoughts about using them..

You can add a fast blow fuse or any fuse for that matter, in series on the LED string to help reduce some of the risk from driver malfunction. Years back I had a few drivers go bad but on the other hand it could have been caused by less than perfect connections somewhere in the LED string (back in the copper trace days).

When it comes to drivers I am mostly concerned with efficiency. A typical driver will be 75-80% efficient versus an advanced driver which can be 87-90%. That makes a huge difference when you scale it up. 90% really should be our goal as that is similar to HPS digital ballasts. I measured these cheapos at 88-91%. You can load up the strings to about 30watts but the output drops down to just over 600mA. That is perfect for vegging or if you are really trying to crank up the efficiency of your lamp by running soft.

Another of my favorite drivers is this eBay deal. You can load these drivers up to about 40vF and their output will remain steady. They range from 680mA-740mA) They are only 80% efficient but they do have a very healthy power factor (.9) which is helpful if you get a power outage and want to use your LEDs on a battery/inverter backup system.

If you are dealing with a smaller build and you just want the best, check out the inventronics or hyperon. They claim 88% efficiency and dimmable can be handy in some cases. Meanwell drivers are well built but all that I have tested have been 80% efficient and with a poor power factor (.6).

 

[SupraSPL]

I'd like to collate the information i've gathered somewhere so someone with a more experienced eye could cast a look over it, point to better sources (for better binned solutions) and add to it if i've missed any important new chips

If you'd like to start a thread for your build Id be happy to look it over and contribute.

 

[thestickyickyicky]

Hi SupraSPL, perhaps you could take a look over here for me? I'd really appreciate any help and guidance you could offer as to help me figure out what I should be ordering right now at the end of 2013 with latest goings on. Really appreciate all your contributions to the LED world .

 

[Someacdude]

Awesome guys.
I feellike a idiot, 30 years in the hvac business, 90 percent electrical and i never even considered building my own.
So what i did was look up my former favorite flashlight co and coppied and pasted the leds they use.
But,,,,,will these work?

http://www.foursevens.com/products/flashlights/Maelstrom