Another Cree CXA3070 DIY Thread

captainmorgan

Well-Known Member
I blame Supra and his DIY thread for making me do this,I couldn't help myself.
Much of the info that I'll post is thanks to Supra and other contributors in his thread.
I ordered parts for 4 of these and have most of the parts now,so it's time to start the thread.


Cree CXA3070 Z4 3000k
Mean Well LPC-60-1400
Arctic Alpine 11 Plus
Ideal Solderless COB Holder
Ebay 12v Fan Power Supply
 

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Chronikool

Well-Known Member
I blame Supra and his DIY thread for making me do this,I couldn't help myself.
Much of the info that I'll post is thanks to Supra and other contributors in his thread.
I ordered parts for 4 of these and have most of the parts now,so it's time to start the thread.


Cree CXA3070 Z4 3000k
Mean Well LPC-60-1400
Arctic Alpine 11 Plus
Ideal Solderless COB Holder
Ebay 12v Fan Power Supply
Haha....welcome to 'team Awesome' and the addiction to follow... :)
 

Bueno Time

Well-Known Member
Nice parts choices, very similar to mine but you have 2x as many. I also blame Supra for my recent expenditures...

Not sure if you planned to but I would sand and polish the bottom part of the heatsinks, my Alpine 11 Plus heatsinks were fairly rough on the bottom like it was just sanded with fairly coarse sand paper on a belt sander. Kind of a pain took me a bit over an hour to polish both of my Alpine 11 heatsinks by hand. It is worth it though the better the surface the cob sits on will aid in keeping the cob running cooler and that increases the efficiency. I figure its quite worth the effort.

Ill be watching this.
 

SupraSPL

Well-Known Member
Looking forward to seeing this build! Cap if you are interested in the technical details, this setup should dissipate about 208W @ 39.3% efficient. 81.7 PAR Watts. 128 lumens/W.

If it makes everyone feel better, I buy LEDs that I don't even need and then have to think up valid uses for them. I have them on my front porch, motion lights, a dozen headlamps, over the stove and a dozen other nerdy projects :joint:

Good call bueno time, I am a big fan of flattening the heatsink, it is surprising how much efficiency you gain from a lower Tj. Last time I wet sanded with 80 grit (alot) ->180-> 320->600->1000. I can vouch for the quality of this sellers silicon carbine wet or dry kits. I highly recommend wet sanding outdoors to avoid inhaling aluminum dust.

Stack of heatsinks drying out, flattening these to 1000 grit took 3-4 hours with a palm sander.
 
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stardustsailor

Well-Known Member
We should make a club " The CXA DIYers aka Blamers of SupraSPL ....
LOL!

:mrgreen:

Nice work Supra ,with the heatsinks ....
I trust much in 'heatsink pro-preparation' ,myself also ...
I go up to 2500 ( Maybe the EU 2500 is the US 1000 ? I think something like that ..
'Cause with EU 80 grit...
You can cut down a tree ,not just sand aluminium !!!-In a matter of speaking ....
I think US 80 is something like ~200 EU grit ...)
 

medicinehuman

Well-Known Member
I'm hooked on this thread, I have all way's been a DYI guy, just not to technical like you fellow's. I'm going to start gathering some part's soon and should be able to doit, even if I don't understand all the detail's. Thanks for some good reading and great info.
 

captainmorgan

Well-Known Member
Getting set up to lap my heatsinks,I've got some experience with this from my computer overclocking days. For these I'm just using 220,400,800 and 1000 wet sand paper,but with CPU's and their heatsinks I would also use 1500 and 2000 so the copper would end up mirror like. I still have my 12"x12" marble tile but you can also use a piece of glass or mirror. Easy to do,you just need some patients.

That was a bit of a workout doing all four at one sitting. The main object besides smoothness is to make sure it's perfectly flat,most heatsinks are not. That's why you do the sanding on a flat surface like glass or in my case,marble. You put your sandpaper on your flat surface and wet it,then you pull your heatsink towards you applying slight pressure counting your strokes then rotate the heatsink 90 degrees and do the same number of strokes then turn 90 again and repeat and 90 again and repeat. Doing equal strokes in each direction helps to keep it flat. You do this with the 220 to start until you see that the entire surface is flat then move through each grade when the surface shows a complete new finish move to the next. 1000 grit should be fine for a finish unless you want to get a little obsessive and use 1500 and 2000. Here's a pic of one finished.
 

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PetFlora

Well-Known Member
LMAO yep the Cree datasheet mentioned that thankfully. When they recommended 1000 grit that is referring to the US version.
Did you check out the thermal pad link I provided on one of your threads? Would it compensate for an imperfect surface?
 

tightpockt

Well-Known Member
Fuckin' A...I've been hooked on these DIY led build threads for like 4 days now. This is almost exactly what I want to do but I can't decide if I should just wait for the 3590's to come out (in the 2700k-3000k range. I know the 5k is out)
If that holder accommodates the 3590 i might just say fuck it and start ordering parts. As the upgrade would be easy peasy.
How much did it all cost? I also
had the idea to string some 660nm 3w around the perimeter of the heatsink but that would for sure up the cost with extra drivers and the led
diodes.
Also, would self tapping metal screws work? I don't have a drill press or a a tapping kit
 

Mohican

Well-Known Member
Taps are cheap at HomeDepot and you can do aluminum by hand just fine.

For future reference all, you can get used drill presses and other industrial machines used for cheap. I had to drive 30 minutes but I got a killer drill press like the one I had in shop class. Just make sure it is set up for regular 120V household electrical.

Nice tip on the glass or marble for wet sanding!

This is going to be awesome!
 

captainmorgan

Well-Known Member
where did you get the ideal holders? you just ordered a pack of 50 from them?
$2 each
http://www.newark.com/ideal/50-2234c/led-holder-cxa30-array-series/dp/90W0065?CMP=AFC-OP

Fuckin' A...I've been hooked on these DIY led build threads for like 4 days now. This is almost exactly what I want to do but I can't decide if I should just wait for the 3590's to come out (in the 2700k-3000k range. I know the 5k is out)
If that holder accommodates the 3590 i might just say fuck it and start ordering parts. As the upgrade would be easy peasy.
How much did it all cost? I also
had the idea to string some 660nm 3w around the perimeter of the heatsink but that would for sure up the cost with extra drivers and the led
diodes.
Also, would self tapping metal screws work? I don't have a drill press or a a tapping kit
It's a different holder for the 35's and I don't think they make a self tapper that small.
http://www.idealindustries.com/media/pdfs/products/brochures/Cree_Chip_Lok_Sell_sheet.pdf

Taps are cheap at HomeDepot and you can do aluminum by hand just fine.

For future reference all, you can get used drill presses and other industrial machines used for cheap. I had to drive 30 minutes but I got a killer drill press like the one I had in shop class. Just make sure it is set up for regular 120V household electrical.

Nice tip on the glass or marble for wet sanding!

This is going to be awesome!
#5-40 tap takes a #38 drill (.1015)which is pretty small,I have a fastener wholesaler near me that has all that specialty stuff.
 

Mellodrama

Well-Known Member
Also, would self tapping metal screws work? I don't have a drill press or a a tapping kit
Getting the right tap and drill bit is easy. Just look up a chart, like this one

http://www.boltdepot.com/fastener-information/us-tap-drill-size.aspx

I only have hands-on experience with the Ideal holders, but I'm sure the Molex are the same. Tightening them down correctly is not a task to be taken lightly. You want the two screws to be even, and just the right amount of force. If you go to the Ideal website

http://www.idealindustries.com/media/pdfs/products/instructions/ND_7868-6_50-21_Instructions.pdf

the instructions say 2.5 - 4.5 inch pounds. That's a tiny amount of force. Small machine screws have fine threads, making it fairly easy to adjust the torque with a small twist of the screwdriver. Self-tappers have large coarse threads, which would be much less effective for adjusting torque.

Self-tapping metal screws are designed to be used in an application where you drill completely through the metal and the "drill" part of the screw goes out the other side. A self-tapper wouldn't work in a blind hole, which is probably what you're gonna have if you're drilling into a heatsink.

Just my two cents, but I think self-tappers are a bad idea. As cap'n morgan notes, I'm not at all sure you could find ones that small...

It looks like Ideal has Cree 35XX series holders. They're are a different part # than the 30XX series. The 30XX are part # 50-2234C. The 35XX are 50-2303CR.

http://www.idealindustries.com/products/oem/led_holders/cree.jsp

Oh, whoops, the cap'n already covered that. Sorry..

I agree with Mohican. I'd want a drill press for drilling the holes, but tapping them was easily done by hand. It would have been better with a real tap wrench, but I used a small Vise-Grip instead. And I would definitely use a tapping fluid, like Rapid-Tap.
 
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tightpockt

Well-Known Member
Getting the right tap and drill bit is easy. Just look up a chart, like this one

http://www.boltdepot.com/fastener-information/us-tap-drill-size.aspx

I only have hands-on experience with the Ideal holders, but I'm sure the Molex are the same. Tightening them down correctly is not a task to be taken lightly. You want the two screws to be even, and just the right amount of force. If you go to the Ideal website

http://www.idealindustries.com/media/pdfs/products/instructions/ND_7868-6_50-21_Instructions.pdf

the instructions say 2.5 - 4.5 inch pounds. That's a tiny amount of force. Small machine screws have fine threads, making it fairly easy to adjust the torque with a small twist of the screwdriver. Self-tappers have large coarse threads, which would be much less effective for adjusting torque.

Self-tapping metal screws are designed to be used in an application where you drill completely through the metal and the "drill" part of the screw goes out the other side. A self-tapper wouldn't work in a blind hole, which is probably what you're gonna have if you're drilling into a heatsink.

Just my two cents, but I think self-tappers are a bad idea. As cap'n morgan notes, I'm not at all sure you could find ones that small...

It looks like Ideal has Cree 35XX series holders. They're are a different part # than the 30XX series. The 30XX are part # 50-2234C. The 35XX are 50-2303CR.

http://www.idealindustries.com/products/oem/led_holders/cree.jsp

Oh, whoops, the cap'n already covered that. Sorry..

I agree with Mohican. I'd want a drill press for drilling the holes, but tapping them was easily done by hand. It would have been better with a real tap wrench, but I used a small Vise-Grip instead. And I would definitely use a tapping fluid, like Rapid-Tap.
Good info
 
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