DIY COB LED build - 6 Cree CXB3070 220W

[Justwannagrow]

Didn't realize they were much different price wise on the other side of the pond? Here a vero29 is between $21-$28 USD even more some places. Which ain't bad unless you need 20 of them

 

[Caconym]

Cheers for the estimate Caconym!
Plug type is something I'm very familiar with .

No problem

 

[Caconym]

Yeah I could really careless about your location that was just curriosty lol more if where you got everything from one place as everywhere I've looked you have to get different parts at different places with the exception of cobkits and rapid which are kinda over priced. No big deal either way

I wasn't trying to be funny I got my parts from Mouser, there aren't many other options to get everything from the same supplier over here. The cheapest I saw a vero29 converts to around $40 US and my Cree chips were about the same price.

 

[Weedman613]

I just built my first one.
200w full spectrum Cob.

 

[Caconym]

Been working on the build again today, got my wiring finished off just need to mount the COBs and push fit the flexes to the terminals on the holders.

Resistor and potentiometer soldered up for dimming circuit

Heatshrink on the dimming circuit for insulation and added strength

Mounted the dimmer on this tub which also holds all the wiring for the COB power leads.

 

[Caconym]

I started drilling and tapping one of the heatsinks, unfortunately despite measuring countless times I've drilled the holes in the wrong place (could be the brownies I ate ). Took some photos during the process though

Made a paper template for the centres of the holes and used this to make a jig out of UPVC soffit I had lying around. Taped the jig to the heatsink and then punched centres for the holes through the holes in the jig.

Checking the punched centres against the paper template

About to drill the heatsink. I've removed the fan and supported the heatsink on scrap timber to avoid damage. I used PTFE spray lube to lubricate and cool the bit during drilling.

Checking the drilled holes against the paper template.

About to tap the hole. I ended up mounting the tap in the drill and going very slow with the torque setting on the drill chuck turned down low. I went forward a few turns and then back a little and so on, using the spray lube again. This seemed to work pretty well as the aluminium was quite soft.

Checking the machine screw threads into the heatsink. It went in fine no stiffness. You can see the holder I'm using in more detail here.

Rubbed the heatsink down with fine sandpaper to ensure good contact with the chip via the thermal grease.

Cleaned the heatsink before mounting the chip with nail polish remover and tissue.

All the gunk that came off the heatsink.

I got to this point and then realised I'd drilled 10mm too close together... Can't read a ruler apparently. So I've stopped for a smoke and something to eat

Peace.

 

[Caconym]

View of the other side of my super bodge junction lunchbox with dimmer assembly.

Drilled two holes in the junction/lunchbox lid so I can screw it onto the ceiling of my grow box and then clip the box onto it.

 

[Caconym]

Discovered today that I will need to drill two additional holes in the heatsinks to accommodate positioning pins on the COB holders.
The terrible drawing above shows the measurements for marking out the centres of the holes. The Bs are holes for bolts and Ps are holes for pins. A 2.5mm hole will accept the pins which conveniently is the same size as the holes for the M3 machine screws.

New jig I made with all 4 holes in the right place. I cut it the same size as the heatsink footprint so I can centre the jig easily. This is the underneath of the jig, I marked the holes on this side but mirrored for better accuracy as this side will be in contact with the heatsink.

 

[Caconym]

First COB mounted. A lot of fiddling around and re-doing things. Hopefully now I have my process dialed in. I wouldn't recommend using these two part holders unless you have access to proper tools (pillar drill at least) as they need to be very precisely mounted and it's incredibly hard doing it by eye with hand tools. I wish I'd looked harder for 1-piece holders.

 

[I like Cheese]

It's looking good

 

[Caconym]

It's looking good

Thanks hopefully I'll get all six chips mounted today and then I can test it all out.

 

[Caconym]

Got all six chips mounted today, just the fans to wire up tomorrow and I'm good to go

 

[I like Cheese]

Got all six chips mounted today, just the fans to wire up tomorrow and I'm good to go

Looking forward to seeing them lit up

 

[Caconym]

Looking forward to seeing them lit up

Me too! The build has been somewhat stressful.

 

[Lady Antheia]

This is really coming together. Nice job!

 

[Caconym]

This is really coming together. Nice job!

Thanks your girls are looking well in their new pots.

 

[Caconym]

Hit a bit of a snag, can't get the wires to push-fit into the COB holders, waiting on some hookup wire off ebay.

 

[I like Cheese]

You can try soldering the ends and see if that helps ?

 

[Caconym]

You can try soldering the ends and see if that helps ?

I tried this already, I think the wire I was using was just a little too thick and my soldering skills are mediocre as well so some ended up a bit lumpy. The hookup wire should give me a perfect connection just a shame having to wait when I thought I was nearly finished.

 

[I like Cheese]

All great things take a little time, and it is worth the wait this is also worth a look at.

Flower initiator