The Reef Tank banner
1 - 20 of 237 Posts

· Registered
Joined
·
2,058 Posts
Discussion Starter · #1 · (Edited)
First...Never Buy Anything from Skimz. They will ignore you if you have a problem with their product. They are located in Singapore and do not respond to product defects. They don't stand by their products, so don't buy them.

I randomly decided to install LEDs on my 180 before I start my fish room addition. So here's what I'm getting into. :eek:

SUMMARY ON PAGE 13, POST #193


My purpose for this build and thread is to provide a complete DIY LED build from start to finish. This is my first time doing this exact project so I will also explain the bumps in the road as I go so maybe someone can learn from my mistake. If this works well, hopefully others can use it as a reference. If you have the same tank as me and it works then you can just copy me :) i will share all circuitry and coding for the controller as well.

Plans for this build


Part 1 - Build Fixture
Part 2 - Install LEDs and drivers
Part 3 - Install controller and program to be run


Part 1 - Build Fixture

Materials:
1/8" x 1" Aluminum flat bar
3/4" Aluminum Channel
3/16" Pop Rivets
Thermal adhesive compound or pad

Pre-made Aluminum Heatsink vs. DIY Heatsink

For me, this was a pretty easy decision and here is why:

Pre-made
When pricing heatsinks the best source that I have been recommended to will not work. For pre-fabbed, the largest is a 10 inch profile and only 4 feet long for $180. Aside from price, the dimensions just won't work. Even if I had the longest one cut into three sections for my tank, the 10 in profile would still cram the LEDs into too tight of formation and not give me as much control over the lights.

While the amount of fins on these heatsinks would be ideal for the heat, its just not an option.

DIY Heatink
Building the fixture out of aluminum flat bar and channel may not be enough heat dissipation for a closed hood, but I am lucky enough to have a sump room. With this I can aide in the heat dissipation by running a decent size fan across it when the lights are on.

The Build

I have attached a layout of my LEDs and the basic structure of the fixture. By going the DIY route I am able to shape the fixture to my tank. I can control where the light goes much easier, as well as avoiding wasted light into the overflows.

If you notice on the "side view," the front of the fixture will angle two rows of lights. The two front rows will be angled well enough to provide more light to the bulk of the corals from a different angel. (I'm very interested to see how this works out) The very first row is angled the most with all royal blues to make those colors pop extra, while the corals are still receiving the white light from directly above. The effect I am hoping for is less direct light onto the substrate and more on the corals. The substrate will light well enough from the ambient rays. I think it would look good if the corals stood out in contrast to a "not so white" bottom.

Once I have the flat bar cut, I will assemble it with pop rivets and thermal adhesive compound. Same with the channel. If the heat is too great upon testing I can simply add more surface area. But I really think that the spacing of the LEDs, open design, and fan that I won't have an issue. But we'll see.

I did some test pieces tonight and will begin assembling it tomorrow. I will post some pics.

Part 2 - Install LEDs and Drivers

- For this project I chose to use 56 Cree XR-E Royal Blue and 40 Cree XR-E Q5 Cool White. I went with the Q5 solely because there are no optics for the XP-G R5. Lesser of the White light but they will work just great.

- I will first try 60 degree optics. If I decide they aren't good enough I will be able to exchange them.

- For drivers I chose Mean Well ELN-60-48P dimmables. The "P" version will allow me to use PWM dimming control. More on that in Part 3.

The LED arrays will be grouped in 12 from one side to the other for a very specific reason explained in Part 3.

I purchased the LEDs and Drivers from www.rapidled.com

Part 3 - Install controller and program to be run

To control the dimming function I will be using an Arduino Mega board with PWM signaling to the drivers. The regular Arduino only has 6 PWM pins so I had to go with the Mega which has 16 (i think). That will give me independent control of the 8 channels (drivers, or LED banks).

The Arduino Mega will have a Real Time Clock connected as well for accurate time keeping.

The programming will be done through Arduino's free software.

From the Arduino I will connect a homemade circuit to convert the 5v from the board to 10v for the drivers. (PWM Signaling)

Programming Plans

The programming won't be too bad, but here is what I have planned as far as the dimming function is concerned:

- 45 min Sunrise and Sunset. All LEDs will dim on and off gradually.

- At three random times in 10 minutes the LED banks will dim in succession across from either side. This is to simulate cloud passage. A "cloud" could pass from the middle to the left or right as well so its not always the same movement. The frequency, duration and dim level can be adjusted as I see fit or randomized. This way the same "cloud" passage doesn't occur all the time, making my reef even a tiny bit closer to the real thing. The "clouds" can be heavier or lighter and pass slowly or quickly.

That's pretty much it as far as dimming functions go. But I am open to more ideas :)

The program downloads directly to the controller and is "looped."

I am not new to DIY controller boards, but this is my first round with an Arduino. If there is anyone out there with experience show yourself!

My fingers are tired now and I'm sure I forgot some details so if you are interested in this build please give questions or opinions. Updates should come tomorrow.
 

Attachments

· Just send me a PM ;)
Joined
·
16,985 Posts
Looks like a nice setup to me... the only question i have is if the flat bar is going to dissipate enough heat without alot of active cooling...you may want to step up to 1/4" minimum (even thicker would probably be better...)
 

· Just send me a PM ;)
Joined
·
16,985 Posts
As for heat sinks, HeatsinkUSA is not the only source.. i will attach a link to manufacturer that has a varied range of widths that would be more suited for the unit. I searched and they are available in 1" widths, but would recommend at least 1.5" for thermal dissipation..
http://www.aavidthermalloy.com/products/extrusion/products.shtml
 

· Registered
Joined
·
2,058 Posts
Discussion Starter · #5 ·
Looks like a nice setup to me... the only question i have is if the flat bar is going to dissipate enough heat without alot of active cooling...you may want to step up to 1/4" minimum (even thicker would probably be better...)
I did consider 1/4" but the price basically doubles. My understanding is that the surface area will play a larger role than the thickness. While 2x thicker would be better, I don't believe it would provide twice the dissipation.

The heat dissipation will definitely be a trial by error process, but I do know that people have been successful before using these materials.
 

· Registered
Joined
·
2,058 Posts
Discussion Starter · #7 ·
Good luck! check my earlier threads to see my DIY LED build if you need some ideas or help. You won't be disappointed with the results. LEDs look amazing over a tank...
Excellent, I will definitely check yours out.....I'm flying blind baby!
 

· Registered
Joined
·
2,058 Posts
Discussion Starter · #8 ·
As for heat sinks, HeatsinkUSA is not the only source.. i will attach a link to manufacturer that has a varied range of widths that would be more suited for the unit. I searched and they are available in 1" widths, but would recommend at least 1.5" for thermal dissipation..
http://www.aavidthermalloy.com/products/extrusion/products.shtml
I'm gonna run by a local supplier of parts today and see what they might have for heatsinks. I'm not 100% on the channel just yet. If I can find smaller individual heat sinks to mount directly above each LED I will probably go that route.
 

· Just send me a PM ;)
Joined
·
16,985 Posts
I did consider 1/4" but the price basically doubles. My understanding is that the surface area will play a larger role than the thickness. While 2x thicker would be better, I don't believe it would provide twice the dissipation.

The heat dissipation will definitely be a trial by error process, but I do know that people have been successful before using these materials.
See a heat sink is not just about dissipation of heat as much as it is storing and taking in heat to be dissipated... therefore the name heatsink. You need to be able to store heat and pull it away from where you want to keep cool. A thinner piece will allow fast cooling but will also not allow fluctuations in thermal release of the heat as effectively as a thicker material will...
 

· Registered
Joined
·
2,058 Posts
Discussion Starter · #10 ·
See a heat sink is not just about dissipation of heat as much as it is storing and taking in heat to be dissipated... therefore the name heatsink. You need to be able to store heat and pull it away from where you want to keep cool. A thinner piece will allow fast cooling but will also not allow fluctuations in thermal release of the heat as effectively as a thicker material will...
I see what you meant Tony. I suppose the greatest cooling would come from the fan or fans that are not mounted on the heatsink itself, correct?

I went to a few places today and could not find a more economical/sufficient heatsink so I will give the channel bar a test round when the LEDs arrive at the end of the week.

Side note: Boy I wish larger tubes of thermal compound were easier to find!

Anyone know about how many degrees fahrenheit these Crees operate at?
 

· Registered
Joined
·
1 Posts
Why use single emitters when Arrays are available?

I have many clients using LED arrays successfully in this application.
Check out Bridgelux cool white 360lm & 400lm products to start.
A simple driver solution and a heat sink is all that is required for good quality white light.
The array mounts directly onto the heat sink. Use a good quality thermal interface material such as Berquist A1500 sil pad. The application notes and data specifications are all posted on the Bridgelux website.
 

· Registered
Joined
·
2,058 Posts
Discussion Starter · #12 ·
Not a whole lot done today, but a good start

I got all of the pieces cuts for the frame and some of the left side done. The joints are very strong with the rivets and thermal compound between. Should make some good headway tomorrow.

Building Materials cost = ~$150





 

· Registered
Joined
·
2,058 Posts
Discussion Starter · #14 ·
Got the frame done and one channel on. As I build this I am feeling more confident that this fixture/heatsink will work.

I choose to mount the channels in this direction so I can add more to it if needed later, as well as the fact that the fan blow across in that direction. Cool air will be able to travel through the channels with little resistance.





Got the goods today!

After placing a few LEDs on the fixture I am worried that they are too spaced out. So I will either need to mount them in a closer arrangement or add LEDs. I'll do some searches and see what spacing, fixture distance from tank, and optic choices may give me what I want.

Right now I have 60 degrees....may have to go with something else. Can't say anything really until I try them on the tank.

 
1 - 20 of 237 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top