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300 watt DIY CREE COB LED fixture

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Howdy OG,


Been building an 300 watt cob fixture last couple of weeks, Tought to post a little summary of the build report i made on WF.




- Mean well HLG-320H-C1400B

- 4x COB led 3070 3000K AD bin

- 2x COB led 3590 3500K CD bin

- 4x ideal led cob holder

- 2 x ideal led cob holder

- 6x passive heat sinks 130x70mm

- thermal cooling paste




Frame and building materials

- 6m1 aluminium 30x30x3 mm L profile

- 28x m4 bolts

- 28x m4 nuts

- 28x m4 rings

- screws cob 3070 led holders

- 4x m3 schroeven cob 3590 led holders





- 1x connection box

- 1x 5m1 wire 3x1,5mm grid

- wago clamps

- 4 m1 0,75mm wire COBS






Made 8 pieces of 65cm long to make the frame. The heatsinks are bolted on the profiles.






Prepped the middle pieces for bolting on the frame and looked where the driver and connection box need to come.



Things needed for putting the heatsinks and cobs together



Marked the holders on the +



Applied cooling paste on the back of the cobs




Screwing the cob holders and cobs on to the heatsinks



All done



Made an drawing how to wire the cobs for my own control



Wire the cobs





Connecting wires in connection box





Fixture in an DR80 tent.







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Damn Worm,being an old Mine Electrician, I can appreciate the fine work u have done and from what I see , done it perfect.!!


can't wait to see a grow in there..


best vibes and thanks for showing.

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<p>Cool I have a few AMD and Intel heatsinks lying around i might give this a go what was the most expensive part?

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Hello mein freund!






Thanks man! Need to be safe and up to par cause i don´t want to electrocute myself or start a fire ;) .


Will post some pics of the grow in my unfinished Selene grow report at Sannie´s section.




Thanks man! Your kind words ar appreciated!




The most expensive parts are the driver and cobs, but it all depends on what you want to do. There are cheaper versions of cob leds and drivers on the market.


What i´ve paid for the lighting parts 1,5 month ago excl shipping costs (sorry in euro´s)


-Mean well HLG-320H-C1400B €98,50

- COB led 3070 3000K AD bin € 23,50 a piece

- 2x COB led 3590 3500K CD bin € 39,75 a piece

- 4x ideal led cob holder €1,78 a piece

- 2 x ideal led cob holder € 1,78 a piece

- 6x passieve heat sinks 130x70mm € 9,- a piece




Thanks man! The lighting components as stated in the above i´ve sourced at kingbrite. https://kingbriteled.en.alibaba.com/


The rest i´ve sourced it at a lokal hardware store and online shop.


Nope I am not going to wire it for dimming, if i want less light on the plants i will pull up the fixture. ;) .





Did some measuring of the heatsinks and cobs today. Im pretty impressed how cool the are.


Temp cob



Heatsink in front



Heatsink in the middle



Temp driver







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<p>OK thanks for the run down on the price, Mean well are good quality drivers I have a Harvard one lying about max 48w not enough to power a COB I suspect and it had two settings 350ma 700ma. Really neat build, from the pictures it looks like you overdone it with the thermal grease you only want it to get in the grooves. Too Much thermal grease and it over heats.

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You are completely right on the thermal paste, it was the first cob i put it on. Big hands and small dose pump doesn´t work well. Scrapped most of it off with a plastic card and used the excess paste on the other cobs.



About your driver:


Amparage xVoltage= Watt


If you run an 36v cob on 700ma, the cob will use about 25watts of power. So when you use the driver you already got you can run 2 cobs.


If you run an 36v cob on 350ma, the cob will use about 12,6 watts of power. So when you use the driver you already got you can run 4 cobs.





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Because of some fellow growers pointing out the Cobs were to close to the walls. I downloaded an lux app on my phone to see how the lightspread was in the tent. After first time using app i could see the lightspread wasn't great. I took the cob fixture out and shifted both sides in for about 4 cm / 1.75 inch each, in total the cobs are 8 cm 3.5 inch closer together now. The lightspread is a little better but not optimal, see pics below.


Before shifting cobs











After shifting cobs










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Thanks Argo!






The max power draw i measured from the wall is 318W.






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Thanks for all this helpful info. I ended up ordering from King Brite and had a great experience. Shipping only took 7 days from China FWIW.


How far apart are your COBs in the new position? How far off the canopy do you run this rig?


I'm making (3) 5000k double units to supplement HPS. Mine run at 2.5A, and I have found that they work well spaced about 24-30" center to center and will light a 2'x4' area quite nicely for Veg, and only pulls 180W. I know....pics or it didn't happen...they're coming.


Again, thanks for all your documentation.

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