CellarDweller
Well-Known Member
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.
DiY LED - Cree CXA3070
- Thread starter SupraSPL
- Start date
alesh
Well-Known Member
Free shipping?! How many did you order?
CellarDweller
Well-Known Member
8!!!
alesh
Well-Known Member
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.
CellarDweller
Well-Known Member
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.
thank u imp...
would you post a foto of the holder mounted....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.
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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Mellodrama
Well-Known Member
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.
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.
medicinehuman
Well-Known Member
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.
beppe75
Well-Known Member
thanks man... it looks good and clean...
beppe75
Well-Known Member
well... thats some great news... thank you.
i'll definetely buy them.
beppe75
Well-Known Member
can you cellar post what reflector adapters did you ordered...
i'm currently looking for them...
thanks
edit 1 : cxa3590 holders out of stock @ arrow
CellarDweller
Well-Known Member
50-2100AN .....but they are for the cxa3070 holder.can you cellar post what reflector adapters did you ordered...
i'm currently looking for them...
thanks
edit 1 : cxa3590 holders out of stock @ arrow
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).
beppe75
Well-Known Member
thanks mate ... really helpful.
CellarDweller
Well-Known Member
I've really enjoyed the learning process and the sharing of information on this forum. To think that I might actually be able to add value to someone else's journey is probably the most enriching return yet
SupraSPL
Well-Known Member
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.
Mellodrama
Well-Known Member
+1I 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.
I like the toothpick idea. I'd been using a jeweler's screwdriver. A toothpick's more forgiving.
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Mellodrama
Well-Known Member
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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