# DIY 48" LED fixture build



## easternversant (Sep 4, 2012)

Hi all,

Well, there are plenty of these floating around the internet (and one by our own nonliteral), but not too many here. I figured I'd give my process as well as thoughts to help people that are building or considering a build.

DISCLAIMER: I am not an electrician. I literally know nothing about electrical work other than a very basic base from what I remember of high school physics and the knowledge that messing up can A) shock and hurt me and B) start a fire and roast my frogs. THIS IS NOT A HOW-TO GUIDE merely how I did this. If you attempt something of this manner, I am not responsible for any maladies which may befall you, your frogs, or your loved ones.

OK, now that we've had our legal fun, on to the actual fun!

I ordered a 4.8" wide, 48" long heatsink from heatsinkusa. Why 4.8"? Well, frankly because it was cheaper than the 3.5" I was going to purchase and extra mass to dissipate heat is always a good thing. I easily could have purchased a 46" sink.

I cleaned this off with rubbing alcohol and then marked up where I wanted to place the pucks.


Rubbing alcohol is also good for when you mess up and want to re-mark placements.

Then, my box of goodies finally arrived!


I tested each individual LED to make sure it worked BEFORE soldering it or attaching it to the heatsink.


Sanyo Eneloops are the world's greatest rechargable batteries. I use these exclusively, and in awful conditions in the field (freezing temps all the way to rainforests). I suggest you also use these exclusively in the future. Note: I'm not being paid by Sanyo....but if you are a Sanyo rep I would happily accept compensation! 

Retina pro safety tip: Find and old pair of batteries to do this part, the LED won't be quite so eye-blinkingly, purple-orange spotty blinding that way. This pair I'd forgotten to charge after they stopped shooting my camera flash....probably 6 months ago. Seriously, Eneloops. Also, these .

End, part 1.


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## easternversant (Sep 4, 2012)

Next up is to place the LEDs on the sink. There are a few ways to do this, but the two main ones seem to be to screw them in place or to use thermal adhesive. I opted for the latter because it is easier and because the adhesive serves to both place it on the sink and conduct heat away from the diodes.

I used Arctic Alumina thermal adhesive because that is what came with the kit I bought. If you are drilling them in place I think you could get away with thermal grease, but I would still use the adhesive.

The adhesive is a two parter, mix equal parts and apply to the back of your LED star and then smush it down on the sink. According to RapidLED you should use a very small amount (see here).

You should mix a very small batch at a time, maybe enough for 5-10 LEDs. I would err on the side of caution here, and I did 6 per batch at the most. This stuff dries quickly.

You should now have your fancy LEDs on the heatsink!


You should let the thermal adhesive set at this point. I'm impatient, so I only waited 4 hours but probably should've waited longer....

And because this was a a boring part 2, here is a leuc on a ladder:


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## easternversant (Sep 4, 2012)

Next up: soldering. A number of suppliers actually offer solderless kits, but they are more expensive and it kind of feels like cheating to me. Soldering is not difficult, and it shouldn't dissuade you from attempting a build like this.

A few tips: have a stand to use for your iron when not in use, a sponge, and practice before attempting this with any of your LEDs! I had an old 25' ethernet cable which I sacrificed for the purpose. There are 6 individual strings of 24 AWG wire within, so you could easily do the entire build with one string of sacrificed ethernet cable. Practice makes perfect with soldering (I was much better towards the end!) and a good soldering iron is worth it. I used an $8 60w soldering iron and burnt the tip, likely giving myself cancer in the process. An old 40w iron that my father bequeathed to me a while back worked far better.

Make sure to tin your iron tip (get your mind out of the gutter!) prior to using. It should be a shiny silver at all times you are actively attempting to solder. There are plenty of youtube videos out there about soldering and tinning, they are likely worth 20 minutes of your time. 

So it is time to heat up your iron and grab a cool one.

I really should be getting paid for all this product placement...

I then tinned one of the positive and negative terminals on each LED star. When I placed these on the sink, I placed all of them in the same orientation so I could avoid my own confusion. This is more or less what your LED should look like after you've tinned them all:


After this you are ready to wire it up! Obviously you want to go from the +LED- to +LED- to +LED- etc all the way through. Once you've wired up one string of diodes you should have a remaining positive and negative terminal. If you don't, well I'm not sure how you are going to power it. Mine are at opposite ends of my sink. I initially tinned the wire prior to placing it on the star, but realized quickly that it wasn't required. I cut all my wire down to pretty close to the exact length to avoid ugly wire all over the place and stripped the last little bit off to expose the wire. You should pick up a small ball of solder on your iron (I used 60/40 by the way) and place the wire on the tinned terminal of the star. This liquid will heat up the wire, which will then heat up the solder on the terminal and allow the wire to sink in to the solder. Remove the iron tip and hold the wire in place for a second or two until the solder returns to the solid state. It is quick and then your wire should be firmly in place.

Do this for however many strings you have. I have two strings, one of neutral white and one cool white which I alternated across the sink for a more even coverage. After wiring both strings it should look similar to this:


I used the supplied 22 AWG for one string and then realized I wouldn't have enough and switched to 24 AWG from my ethernet cable for the second.

Now that you've soldered all this, test each LED star again but test each individual solder. It should go + unsoldered and - unsoldered. Then +soldered -unsoldered and lastly +unsoldered -soldered. Ideally it should blind you thrice per LED in this process. If it didn't, you may have messed up a solder there. OR your batteries are dead and you should replace them.

I've never soldered a damn thing in my life before and I didn't have any trouble with this, so I'm confident that you (all) can as well!



Pro safety tip for cat owners: You will be using a lot of wire (i.e., string) which will attract your cat. This is bad because you will be using expensive electronics and a very hot soldering iron, so have a cat contingency plan in place. Mine was to smack/kick her. I'm not a particularly mean person and I treat animals very well, but she was on my hit list at the time. She had tried to hamstring me the last few mornings and I have the giant scratches on my legs to prove it. Seriously, this cat is 12 pounds of chingona!


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## Dragonfish (Mar 23, 2012)

Tip from a guy that has built a few of these: Tin the pads on the stars before you attach them to the heatsink. Failure to do so can cause the solder to take longer to flow thereby frying your LED. You want to apply heat for as short a time as possible. Found this out the hard way.


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## easternversant (Sep 4, 2012)

Dragonfish said:


> Tip from a guy that has built a few of these: Tin the pads on the stars before you attach them to the heatsink. Failure to do so can cause the solder to take longer to flow thereby frying your LED. You want to apply heat for as short a time as possible. Found this out the hard way.


This is a good idea as well! More updates on this build later....


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## TDK (Oct 6, 2007)

I'd like to see the finished product in action to see how much light it produces. How far away from that are you?


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## easternversant (Sep 4, 2012)

OK, continuing on!

Is everything still unplugged? It should be, because remember post #1 folks--I am not responsible for any injuries/damage that can occur during this process!

After your LEDs are wired together, you are nearly done. At this point, what you do next primarily depends on how you are doing your build. For this build I used 2 Meanwell drivers (ELN-60-48P), one to power each string of LEDs (1 cool and 1 neutral white). These drivers are rated up to 1300 mA, which is below the rating of my LEDs here. 

If I neglected to mention, I'm using Cree XP-G 5w LEDs. These diodes are rated for 1500mA, though most people suggest running LEDs below their maximum to maintain LED longevity. Why 5 watt diodes you ask? Well I'll tell you! I'm using 5 w because I thought they were 3w when I ordered them! Why? Because apparently I am a stupid, stupid customer haha.

In addition, I am using a controller as my dimmer. This controller has 3 preset daylight programs and brightness can be adjusted at ~5% intervals. 

Each driver needs its own power supply. This is fairly easy, just tin both wires from the driver and both from the plug wire, then solder them together. It is really important to then put something over top of them so they never come in contact. I initially neglected this and as a result there were a few sparks...and one extraordinarily manly yelp. Yep. Manly. Learn from my mistakes friends! I suggest acquiring wire nuts to cover your exposed wires. I have 4 for the driver/power connections and you will need 4 more if you have a controller like the one I've purchased.

Now, onwards and upwards! You will also need to wire your driver to a dimming current (if you've got dimmable drivers...which I do). If you don't connect your dimmable driver to a dimming source, it won't light your diodes, so this is an important step. There are 4 wires that you'll need to combine per driver most likely. For my controller (this one by the way), the + dim and - dim just get attached directly to the controller by unscrewing a plate, inserting the wire, and synching it back down with a screwdriver. The same goes for connecting the controller to the (included) power supply. 

However, connecting the driver to the controller gets a little more convoluted. This is primarily because there is a +dim and -dim (which you've already connected above) as well as a + and - which powers the LED string(s). This particular controller has 3 channels. All 3 channels go to the same +dim but get their own slot for -dim. So, if you have 2+ channels spaces gets cramped.

This is just 2 drivers (each with its own channel).


Last step is to solder the + and - side of the driver to the LED string. It should look like this +from driver --> LED +terminal of first LED --> Entire LED string --> -terminal of last LED --> of driver. It gets complicated with all those wires...color coding is really helpful.

Really, you should do the soldering bit first otherwise you'll run out of space. That is what I did in actuality, but I wrote it backwards and got too lazy to rewrite it! These exposed wires should also get wire nuts for safety.


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## slipperheads (Oct 17, 2007)

You know I'm keeping a close eye on this! Thanks the update pal!


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## easternversant (Sep 4, 2012)

At this point I went ahead and hooked it up and mounted it briefly (after a quick trial run). 

IMPORTANT NOTE: IF your driver can supply more power than your LEDs can take you need to open it up and turn down the dimmer (a small piece called the SVR2 which gets gently turned counter-clockwise with a screwdriver in my drivers). If you let too much power through....you risk burning out all of your LEDs....so don't do that. You'll be sad.

I then mounted the heatsink and turned on the lights just to see how it looked. I mounted via a Y mount hanging kit from rapidled. All this required was 4 small holes in your heatsink (maybe 1/16" wide?) and then removing the hook to string the cable through. It is extraordinarily simple. You can even drill between fins of your heatsink. Extra bonus: this method is 

In essence, how you mount your build is possible in a wide variety of options. That said, here is a crappy phone picture of my hanging setup.


At this point I'd only put on a few of the optics as a trial. Here it is in action:


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## slipperheads (Oct 17, 2007)

Very nice, what do you think of them so far?


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## TDK (Oct 6, 2007)

It doesn't look very bright to me. Can the brightness be turned "up"?


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## Dendro Dave (Aug 2, 2005)

TDK said:


> It doesn't look very bright to me. Can the brightness be turned "up"?


I have to agree, nice work, and maybe it is just the pics or my monitor but I'd like twice the brightness on my tanks probably.


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## easternversant (Sep 4, 2012)

TDK said:


> It doesn't look very bright to me. Can the brightness be turned "up"?


Calm down ya'll! I'm getting there!  It is brighter than it looks in this pic, I had the ISO down and the shutter speed up when I took this pic. Here I was just testing whether I wanted to actually attach the optics. 

I decided I did want to add optics--which somehow turned out to be the hardest part of the entire build. Every diode was placed on to the star with a bit of solder, and this proved to make it impossible to place the optics on. I tried picking off the extra solder ball on the top (and often bottom) to the diode, but I couldn't do it easily. So I tried again....with unfortunate results!



This diode got moved off center and now no longer works  I tried to resolder it in place, but no such luck. I'm quite upset about this guy. Luckily for me, it is one of the exterior diodes.

What I ended up doing was taking a sharp carpet knife and shaving bits off of the interior of the optics. I had to do this to fit each INDIVIDUAL DIODE, which was a pain. 

I did, however, manage to get each optic on a diode by just gently placing it on after having cut them to size.


These have no glue or anything on them, and have stayed very well so far. I've had one or two fall off, and removed one to get a little more light on a fireball bromeliad in the back of a tank.


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## easternversant (Sep 4, 2012)

At this point, I placed the fixture back up on the rack. Note, I do suggest having two people to do this for ease/security. You are placing a giant 4' piece of metal over a bunch of glass.

I turned up the lights a bit from the prior pic for this picture. Here it is right after misting.


To give you a bit of background, the tanks on either end are 12x12x18 and the middle tank is an 18x18x24 (which apparently doesn't really fit well on my rack, boo!). The fixture is suspended a few inches off of the glass from the middle tank. For the pic above the drivers is turned down to ~75% overall power. The drivers run at max 1300mA and the LEDs can run at 1500mA. Then to top it off I had the controller dropped down to 15%. So, this thing can be bright.

Since then I've turned the controller up to 25% power, and the _Vrisea_ in the top left of the big middle tank looks almost white to me in person. I think I may have even burnt the fireball in the back (water drops from mist??), which is unfortunate.

I'll take some more pictures in the next day or two and post them. I'll even take individual FTS for comparisons after a month or so.


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## slipperheads (Oct 17, 2007)

Freaking cool. Nice job, great tutorial and amazing inspiration. Thanks for this. I think that although these are 'around,' people get to see different techniques being used for different applications. I love that.


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## nonliteral (Mar 26, 2012)

Dendro Dave said:


> I have to agree, nice work, and maybe it is just the pics or my monitor but I'd like twice the brightness on my tanks probably.


I'm willing to bet those tanks are way brighter than they look in that shot 

It's tough taking pics with bright point source lighting and dark areas, since the camera wants to either meter for the LEDs (and plunge everything else into underexposure) or the tanks (and way overexpose the LEDs). About the best you can do is frame each area separately, or do an HDR image.


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## nonliteral (Mar 26, 2012)

Nice build and write up!



easternversant said:


> At this point, I placed the fixture back up on the rack. Note, I do suggest having two people to do this for ease/security. You are placing a giant 4' piece of metal over a bunch of glass.


My trick for doing this without a helper is usually to put thick folded towels on top of the vivs, and then gently put the heat sink on top of the towels while I mount it. This is substantially easier if all of the vivs are the same height, tho


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## Dendro Dave (Aug 2, 2005)

nonliteral said:


> I'm willing to bet those tanks are way brighter than they look in that shot
> 
> It's tough taking pics with bright point source lighting and dark areas, since the camera wants to either meter for the LEDs (and plunge everything else into underexposure) or the tanks (and way overexpose the LEDs). About the best you can do is frame each area separately, or do an HDR image.


Ya I wondered if it might just be the pics...and his new shot is much brighter and in line with what I would wanna see on my tanks.


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## TDK (Oct 6, 2007)

Yeah--that looks a lot brighter, now keep us posted on plant growth. I'm interested as I may switch over sometime to a system like this.


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## easternversant (Sep 4, 2012)

OK, as requested for plant growth!

Brand new 12x12x18 for some Chazutas one day:


12x12x18 for intermedius


18x18x24 with El Dorado O. pumilios (come oooooooon, breed already!):


The intermedius and pumilio tanks have been under the LEDs since Sunday night. You can't see it in this picture (it is hidden by the _Diffenbachia_ but I have some pilea (aluminum maybe?) that has already grown at least 2 inches in under a week!

I may have burnt the tips on the fireball in the back center of the pum tank! Ah! Perhaps it is too bright...


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## slipperheads (Oct 17, 2007)

Looks great! Do you have an idea of what the total cost was?


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## easternversant (Sep 4, 2012)

§lipperhead said:


> Looks great! Do you have an idea of what the total cost was?


I have a vague idea....but please for the luvva God don't make me calculate it!

I feel confident that you could do it with cheaper LEDs and have it work just as well. I chose Cree because RapidLED answered my questions and because they are an American company. The latter was two-fold, one to support American companies ('Murica!) and secondly because then all the connections would be correct for here.


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## slipperheads (Oct 17, 2007)

I am all for supporting American and small businesses (They make up 80% of our workforce after all!)

What LEDs do you think would be able to do just as good as CREEs that I might look at?


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## easternversant (Sep 4, 2012)

OK, time for an update. 

Pictures as of today, probably ~1.5 months after putting the LED build up. These didn't get light for a few days because I moved. Then it took me an extra few days to get up the courage to plug in via an adapter to the non-grounded outlets in the frog room. Eek. No fires though!

12x12x18 with Chazutas. The Neo Chaquita Linda had 2 teeny pups just starting when I put this viv under the lights...now look! The moss is doing well too, even though I kind of just mist sporadically...I also added an orchid (Bulbophyllum pardalotum or something like that). It seems to be doing OK for my first mini orchid, but hasn't shown any real sign of growth since I put it in ~1 week ago.


18x18x24 for El Dorados. The plant in the front right has grown a few inches, the Pilea are now too tall and need to be pruned back, the Pepperomia is growing, a Macgravia has produced some good growth, and some of the broms have added an inch in new growth from the center. The Vrisea has turned fairly white....I think it might be too much light for that bad boy.


Sneaky El Dorado:


12x12x18 for intermedius. This has seen a bunch of growth too. The top left brom has put out a super long axil that is about 2x the length of any of the others....I don't know why.


This brom has produced two pups since I put under the LEDs. You can also see that the generic sphagnum I had in there has come back to life and is putting out new growth. Muhuhuhahahaha!


It has done pretty well so far, with relatively low heat output. Great for the summers here in NC.


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## clifford (Oct 17, 2008)

Would love to see a photo update of this thread when you get time.


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