Tag Archives: DIY grow light

DIY 130 W LED light Feat. The crescience FLUxEngine

Video with build instructions

This article will cover how to build a solderless LED light thats scalable and very easy to set up. Check out why LEDs are superior.

The build shown here is beginner friendly. You dont have to drill into metal and the boards do not need active or passive cooling, since the framing will be sufficient to do that. If youre more into COBs, check out my 310W COB growlight guide!

This article will cover how to build a solderless LED light thats scalable and very easy to set up. Read more about how LEDs are superior.

Disclaimer: This piece of electronic is a potential fire hazard and should only be put together by electricians or persons with similar know-how. Please refrain from putting in self-made electronics into the wallplug. Dont die!


For this build you can either buy the whole kit from the LED builders website, or you look for a bunch of groove profiles from metal dealer thats suitable for you. Mind that I cant give an amazon link for that, since the orders are most likely to be custom made.

Groove Profile – use these, so you dont have to drill into metal!

I used 30 cm and 38 cm long profiles with a 4cmx4cm crosssection, so you can build a square-shape out of it.

You also need a bunch of metal sliders. Make sure, that the sliders fit the profiles.

Metal sliders that are needed as holes for the screws.

Every slider needs a fitting screw aswell. To connect the framepieces You will also need some angles. There has to be one on the side where you will buy the framing that fits the profile. It should look somewhat like that:

Angle connector for the frame.

For this particular build I used 4 FLUXengines to achieve a total power of 130 W for the 2×2 tent its used in. Be aware, that these boards might require screws with a smaller head, so you dont drill onto the LED modules.

FLUXengine with the power connector in the front and the Samsung lm301b chips on board.

The ELG-150-24A driver is the connection between the wallplug and the boards. You will need one of these. The boards are connected in parallel.

The driver!

You will also need about 50 cm to 1 m of single core copper cables to connect every board with the driver. I suggest you buy two different colors: one for plus, and one for minus. The cross-section of the wire should be between 0.14 mm² and 0.5 mm². Mind that once you used 0.5mm² cables on the connectors, you will not be able to switcht to the smaller ones.

Single core copper cables are easy to clamp!

For further connections and cable collection you will also need to buy WAGO clamps. Two 5-way clamps to connect all the boards in parallel to the driver, and three 2-ways to connect the driver to plug cable for the wall.

Wago Clamps for cable connection.

Last but not least its important to hang the lights from the top of the tent. Get four hook screws in order to do that.

Use these to hang your light!

Take some measurements first

Lay down your frames in front of you and put the boards on top in a symmetrical way. After that you estimate the cable lengths and cut them. Strip the isolation and connect the cables color-coded to + and to the boards and guide them throught the aluminum profiles. Its better to take longer cut here, hust to be save.

After that you take your metal sliders and also guide them through the profiles. You can now screw the boards tightly to the to the frames, and the framepieces to each other. Before you screw together the frame pieces, make sure to have all sliders in the back installed aswell. You wont be able to access the shorter parts anymore or you have to unscrew everything…

Connecting the cables

The schematic shows how its done. Collect all minus and plus cables together and put them into a 5-way WAGO clamp each. The voltage delivered by the driver stays constant while the current gets forced to a maximum output of about 6.3 A.

All cables are connected, the light is hanging safely – time to grow!

Testing and mounting

Four Crescience FLUXengine modules haning in the tent

When everything is connected nice and tight, you can now plug it in and look if it runs. Dont look directly into the light.

Done! This light should draw around 130 W at the wall and is able to light up a 60cm x 60cm grow tent (2’x2′).

Scale up!

The four modules can also be connected to a bigger drivers. Each module is able to put out 60W of light, so if you have the ability to hold down temps, you can also use ELG 240-42 running at 5710 mA to reach about 230 W with this setup. Mind that these chips run hotter and less efficient in this configuration, but will still crush any blurple or HPS lights in comparison.

DIY 310 W COB Growlight for under $350

render picture of diy grow light
SketchUp Render of the DIY COB Light

In this guide I will describe you in all detail what you need and how to manufacture a COB growlight using state of the art LED technology. 

This is instruction is perfect for growareas of 6 ft² – 9 ft² hanging at a minimum height of 45cm. 
I will also assume that you do not want to use an external potentiometer to dim the light. The light is dimmable through the driver directly.

Disclaimer: This guide is an example for one of the most efficient ways to distribute grow light in a 80cm x 80cm grow tent. If your tent has different measurements it is on you to figure out what is best for your setup. This article is more of an inspiration.

Another note: I am not an electrician. If you are not sure about your build please let a friend look through everything. Don’t die! 🙂

Item list

Aluminium L-profile620
Aluminium flat profile16
Screw tap1amazon15
Norm screw set1amazon19
COB Modules4digikey80
MeanWell HLH-320H-2100A1100
Arctic Processor Cooler4amazon56
Thermal glue1amazon8,5
4-way 4-pole Y-splitter1amazon9
12 V / 1A Power plug 1amazon9
Wago clamps1amazon7

Aluminium Profiles

This will be the framing of your light. You will need 7 pieces of aluminium:

top view render of DIY grow light
Light Framing – Red: L-Profiles, Green: cuboid
  • 6 x 515 mm long L-profiles (measurements below)
  • 1 x 515 mm long cubiod (50 mm x 3 mm)
measurements of the L profile
Measurement of the L-profile

The COB Modules: Bridgelux Vero 29 SE 3500K

picture of COB module

This is your work horse. Four of these lights are enough to light up a 3×3 grow area. The BXRC-35E10K0-D-73-SE is able to put out 147 lm/W with a nice 3500k spectrum (warm white).


  • Can I use other COBs aswell? Yes, but make sure the driver you choose fits your setup!
  • Why is this COB better than others? To compare two COBs you first look at the spectrum. This COB has a 3500 K warm white spectrum. After that you compare the effiency. Cheap COBs from amazon likely use COBs that do not reach the output levels of this light at the same power region. With this one you will only need four modules to reach 310W at this efficiency level. 

The Driver: Meanwell HLG-320H-C2100A

This is the heart of your light. The driver will power your COBs. Read more about drivers here. 
This driver is a highly efficient device which will provide you with a constant current of 2100 ma and a voltage range of 76 VDC to 152 VDC.

Thats fitting for the setup! The COBs need a voltage of 36.6 V. We got four of them and connect them in series, resulting in a total voltage of 146.4V .

Wiring schematic for a series connection

To get the same result while wiring everything in parallel you will need a driver that puts out 8.4 A and 36.6 V constant voltage.

Cooling: The Arctic Alpine 64 Plus

This CPU cooler is quiet, can dissipate up to 100 W of thermal energy and is really cheap! It is also possible to use pre drilled passive heatsinks, but these cost at least $30 each.
Disadvantage of active cooling: It can fail!


Disclaimer: I wont provide exact measurments. Just make sure everything is perpenticular and has some kind of symmetry to it.


First use your screw taps to build the framing. Drill holes at the the marked spots and use your screws to hold everything together. Use one of the coolers to check out the right distance between the two profiles on top and bottom, so the coolers can just be put on top of it.
Remember, that you might need some more holes for the hanging.

Attaching the driver to the middle piece and build the frame

Make sure to screw the driver very tightly to the middle piece, exactly in the middle so everything hangs in an even plane in the end. (no tilt)

example for the frame hanging
My solution to hang the light. 

After that you screw the L profiles and the middle piece with the driver togehter. Work as exact as it gets. If done right, the drivers should fit into the gaps.

Framing of the DIY COB
This was my first framing. Its not perfect, but good enough 🙂

Attach the COBs to the coolers

In the case of the Arctic cooler im recommending, there will be a layer of heatconducting paste on it. You have to remove it, before you attach the COB.

Back of arctic alpine cooler
Remove the layer of thermalpaste first

To remove the thermal paste you need to use a special alcohol solution. This one here is sufficient.

heatpaste removal
Use this or an equivalent solution to remove the thermal paste.

After that you can apply the backside of the COB with a little amount of thermal glue. 


Heat paste on COB module
This is a good amount of thermal glue. Let it spread by pressing it on the cooler.

You do not need to spread the thermal glue manually. Just press it on the cooler and let it distribute by pressure.

Wiring and testing the lights

Wago clamps
Use the Wago clamps to connect cables.

Place the COBs attached to the cooler on the framing to determine the amount of cable you need. After that you can start cutting the right amount of cable and wire it to the COBs. Please watch this video if you are not sure how to wire a COB.  Remeber: You use serial wiring.
You now have to attach the input cable to the driver. Just cut open a cold device cable. Make sure you work according to the color coding of the wires. If you fuck up here it can be dangerous! Use the Wago clamps to connect everything.
If you think you have done everything right please DOUBLE CHECK everything.

Attach this to your driver. This is an EU cable!

You can now test the COBs for 5 seconds max. This is important, because the active cooling is not connected yet. Cover your eyes, this is going to be bright! (Im serious here!) 

Power up the cooling

Now that the light works, the last step is to connect the cooling to the power. This is why you have to buy a 4-Way Y-connector. This is used to wire all the fans on the coolers together. Then you just connect the remaining wire to a sufficient power source (12 V, 1 A) and you are done. The cable from the Y-connector has four wires and are color coded as shown here. You only need 12VDC and GND to run the fans. If you are clever you make use of the PWM cable as well to lower the rotation speed if needed.

COB light in a growtent
The DIY COB Light in action!

Have fun growing!