DiY LED - Cree CXA3070

beppe75 said:
well i was intersted in knowing if someone else used this holders....just like you
i've seen this holders @ mouser and they were the cheapest and the only one available i could find , personally.
the ideal cob holders either cost to much in eu or they are difficult to find.
but i can't help unfortunately.
let us know when you solve this... and by the way i think you just have to drill one hole for the screw, but i am no way sure about it...
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Ideal Cob Holders are very easy to obtain in the EU mate......from Arrow USA.....free shipping to the EU!!! And available in single units at around $2 per unit.
 
alesh said:
Nice. Was it shipped from USA or from Europe? Arrow might be a viable source in EU. I've just found out they even have local office really close to the place I used to live.
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Shipped from USA.

Quite unbelievable really. I bought 8 COB holders first. Total value around $16/$17 then 8 reflector adaptors in a separate order...for a similar value. Total shipping $0!!!

Can't get my head around it. Arrow EU don't do the low quantities.
 
beppe75 said:
thank u imp...
would you post a foto of the holder mounted....:-o if you can.
i'm thinking of buying them but i was not sure they worked like the ideal holders that i've seen used extensively on RIU.
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2015-04-03 08.10.05.jpg IMG_2943.jpg
There ya go man those are the best pics I can get right now. I think the ideal holders are probably easier to use, these ones were OK if you take your time and do it right.
 
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I've drilled the wholes and am now using Arctic Silver to put them on, is there any danger in excessive heatpaste, i'm using the ideal cobholders and its difficult to keep everything clean
PS: i just read online that it doesn't conduct electricity
 
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Kuifje, the Ideal holders are a little fussy to use. Did you find my COB Holders - The Basics thread?

Doing a few dry-runs without the paste might be advisable. You know by now that the Ideal holder relies on that tiny spring arm to keep the COB in place. The spring arm can easily lose grip as you're trying to set the holder onto the heatsink. If the COB falls out as you're flipping it over you know you gotta try again. What's more dangerous is if the COB slips partially out as you set the holder in place. If that happens the COB can be damaged as you tighten the screws. Triple-check before tightening!

After a few dry runs, you'll want some alcohol nearby because it's likely that you'll be cleaning things off and starting over at least once. It's hard to keep all the surfaces perfectly clean while you set the COB in the holder, spread the paste, position the COB & holder assembly directly over the tapped holes, etc.

The smallest bit of crud can push most of the COB off the sink, completely destroying thermal transfer. I've seen it. I needed magnification to realize that my install sucked. It looked OK without magnification.

It's very easy to slobber too much paste on and cripple the thermal transfer. Don't do it. Use a credit card or something similar to spread the thinnest layer that you can apply evenly. If the paste keeps peeling right back off as you drag the credit card across, then you gotta thin the paste with a few drops of alcohol stirred in or back off the pressure a little. You can YouTube videos of guys applying thermal paste to their fancy CPU coolers to get an idea.
 
I almost always have to fudge the cobs around a little in there holders, I use a toothpick to move it to where it is set in all the corners properly. If you tighten screws and all of the feet on the holder are flush with heat sink (2 plastic under contacts and 2 metal ones) it should be good. If there is one that is not touching then your cob is not squared up good or your heat sink is cupped or domed.o_O
 
CellarDweller said:
Shipped from USA.

Quite unbelievable really. I bought 8 COB holders first. Total value around $16/$17 then 8 reflector adaptors in a separate order...for a similar value. Total shipping $0!!!

Can't get my head around it. Arrow EU don't do the low quantities.
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can you cellar post what reflector adapters did you ordered...
i'm currently looking for them...:hump:
thanks
edit 1 : cxa3590 holders out of stock @ arrow :wall:
 
beppe75 said:
can you cellar post what reflector adapters did you ordered...
i'm currently looking for them...:hump:
thanks
edit 1 : cxa3590 holders out of stock @ arrow :wall:
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50-2100AN .....but they are for the cxa3070 holder.

If you go on the ideal website it will show you the right numbers. Also Ledil will do it if you look up the reflector you want (basically they license the holder design to Ideal and the Ideal part number is from memory the same as the Ledil number).
 
CellarDweller said:
50-2100AN .....but they are for the cxa3070 holder.

If you go on the ideal website it will show you the right numbers. Also Ledil will do it if you look up the reflector you want (basically they license the holder design to Ideal and the Ideal part number is from memory the same as the Ledil number).
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thanks mate ... really helpful.
 
alesh said:
It's actually 110lm/W but it could still be pretty decent efficiency with such a low CCT.
Spec sheet
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Right, that is why I said 135 lm/ dissipation W. I am trying to take the driver losses out of it to understand where the LED efficiency is, so I guessed 85% efficient driver. Normally when we talk about lm/W in DIY and HPS we take that out because it is variable.
 
medicinehuman said:
I almost always have to fudge the cobs around a little in there holders, I use a toothpick to move it to where it is set in all the corners properly. If you tighten screws and all of the feet on the holder are flush with heat sink (2 plastic under contacts and 2 metal ones) it should be good. If there is one that is not touching then your cob is not squared up good or your heat sink is cupped or domed.o_O
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+1

I like the toothpick idea. I'd been using a jeweler's screwdriver. A toothpick's more forgiving.
 
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Scotch089 said:
Not supposed to flatten the metal feet out from what I understand
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Thank you, Scotch, for bringing that up. The Ideal holder's metal plate has two dimples that touch down against the heat sink. Some guys were grinding those dimples off. Don't do it. I contacted a rep from Ideal. He confirmed the dimples are there to position the holder at the intended distance from the sink. Before the screws are tightened down (and Ideal recommends a miniscule amount of torque) only the two metal dimples contact the heat sink. Roughly 4 inch/pounds of torque on the two screws (that's what they say!) causes the metal plate to slightly deform. As the plate deforms, the two white nubs should touch down on the sink.

If the white nubs don't make contact you must figure out why. The 2 most likely reasons: there's either a piece of dirt between the COB and the sink, or the COB has slipped partway out of its "pocket". Cranking the screws down harder is unlikely to produce the desired result. My experience is limited to less than a dozen builds, but I believe that further tightening of the screws is more likely to crush the COB than force the holder to set down correctly.

EDIT: Too much thermal paste could keep the white nubs from touching down. I shoulda mentioned that.
 
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