Heatsinks for DIY LED lamps

hi supra spl
whats your opinion of these for cooling 4 cxb3590s at1050ma? (for a light bar style)
i posted this before but link was not in english,so sorry.
its cheep(thine base i think) but i think it could work with 10,752cm (i assumed 4mm base) so 195cm for w.
look like a good find
i ordered these already and will report the quality when i get them
thanks man
http://www.aliexpress.com/store/product/5pcs-lot-90w-High-power-LED-heat-sink-1200-140-20mm-Grille-type-cooling-equipment-for/612700_1851233709.html

One thing I noticed was that all these commercial (not heatsikUSA style ) passive coolers have a thick mass at the COB not like the really thin sinks the above poster is getting
(it cost more to ship than it cost to me )

Fastslappy said:

One thing I noticed was that all these commercial (not heatsikUSA style ) passive coolers have a thick mass at the COB not like the really thin sinks the above poster is getting
(it cost more to ship than it cost to me )

Click to expand...

u realize that its 5 pieces 1200 x 140 x 20 mm right?
yes it is cheep quality as i mentioned before but the heat disperse could be good because of the size and might fit my application.
anyway where im from(not usa) its by far the best value ,and if it can keep the les cool than its fine by me.
im not looking for a cool mechatronix look, just getting the job done .
peace

dude i'm not knockin yer sink Just pointing out a difference that's all
i don't know about 5 each as all i see is arabic on your last link
a us shipping price is the only thing i understand

you could also mount that sink on a thick AL plate Then mount the cob to the AL plate

Fastslappy said:

dude i'm not knockin yer sink Just pointing out a difference that's all
i don't know about 5 each as all i see is arabic on your last link
a us shipping price is the only thing i understand

Click to expand...

sure man,no offense taken
its 5 pieces of 1200x140x20 mm for 185$ shipped ,i try to post it on the international ali express but it keep jumping back to my country site . (its hebrew by the way) the sinks job is to keep the camel cool...LOL

sorry man , wrong language my bad !

Would be used for 25w cobs.

So here's what I have and it seems wrong...

337w of waste heat, so 120" of the 4.6" wide serrated HSUSA sink to handle it passively?

If that's the case it's cheaper than going with the mechatronix.

SupraSPL said:

Yes the 120cm²/ heat W figure is based on the passive friendly profiles with fins, horizontally oriented, a low thermal rise and assuming some air movement in the space. If the heatsinks were shaped more efficiently (radial style is a good example) then you could reduce that number. You could reduce the number further if you were willing to accept a higher junction temp, which is what many manufacturers do for their recommendations, probably because they would not expect the LEDs to be run or 12 hours/day.

I have never tested radial heatsink performance, but there are several that do look promising, including the LSB9980-B for $12.61. I would not expect it to do well with a COB at 50W dissipation, but possibly 37W or 25W dissipation.

Click to expand...

can anyone help me with choosing my heatsink ?
i plan on running 4X8 tent with 28Xcxb3590 90 degree reflectors 7 bars of 4 cobs per bar 1050 mA
im not from the us and i cant order from heat sink USA..
i have 3 options of CPU coolers and i need to decrease as much heat as possible but i will save money if not needed
this are the CPU what are you saying any recommended ones for my setup ?

alpine 11 plus
alpine 64 plus
if you have other suitable heat sink to offer me ill be glad to hear :]

I was going with the alpine 11 plus
( newegg has open box ones as well cheaper but limit 5 per
open different acounts to get more $5 saving each .)
But I found a dozen used CPU cooler that appear better than that artic 11

I needed a cheapest & fastest way to get a doz 3590 in the air
So I can plan my next build
the salvage ones were $3.50
& they have heat pipes as well with a copper pad @ the cob point

nogod_ said:

Would be used for 25w cobs.
So here's what I have and it seems wrong...
337w of waste heat, so 120" of the 4.6" wide serrated HSUSA sink to handle it passively?
If that's the case it's cheaper than going with the mechatronix.

Click to expand...

I have always ruled out the 4.6" for passive cooling, because of the relatively close fin spacing, taller fins and thinner base. Horizontal orientation exacerbates those issues. So it would take a higher heatsink temp to get the air convecting out from in between those fins and it would be less likely to benefit from the airflow of the circulation fan. Not to say that the 4.6" would not work, only that there are much more cost effective options. I made that mistake in a big way with the 10.08" profile, now I use them at 300cm²/W passive so they cost me almost 2X and weigh almost 2X vs the 4.9". On top of that they cannot spread the COBs as far apart as I would prefer.

When it comes to active cooling the 4.6" suddenly has too much cooling power in too small of a space, meaning that at 40cm²/W it would pack a lot of COB power very close together, reducing the uniformity in the canopy and resulting in a potentially undesirably high PPFD. Or on the other hand you could spread the COBs properly and get super super cooling, but there are only very small efficiency gains to be had by doing that and the heatsink cost would spike up quite a bit.

For those reasons I have been using the 3.5" for active cooled setups @ 50-80W/COB and the 4.9" or 5,88" for passive cooled @ 25W/COB. 7.28"X5" for passive single COBs at 25-37W ea.

http://www.ebay.com/itm/LED-DIY-Light-Aluminum-Heatsink-12-24-36-48-/270831824949

Here's that same heatsink in the USA , that was just discussed he only has 12" atm
it's the pinned stuff

Water cooling lol.


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FYI- tried to order from Heatsinkusa.com and my paypal got declined, tried to pay by manually entering the card... declined.
called bank, they put a hold on my card because it was out of state purchase.
idk if that's normal, I don't do a lot of online shopping though.
no big deal, just a quick phone call.

amazon has arctic64 coolers on sale no limit $8.99 free prime shipping
it's a price match with NewEgg
but NewEgg has a 5 each limit free shipping on fleabay

http://www.amazon.com/gp/product/B001A5V1K2?psc=1&redirect=true&ref_=od_aui_detailpages00

Yes but they also get cheaper as you buy more on newegg, you only pay 8.49 per if you buy 6-10 and just over $8 per if you buy more than 11

I like Amazon NewEgg has issues these days
newegg has a 5 limit per customer you can order that many but they will cancel it
I already got my shipping notice from Amazon I'll have them Saturday newegg can't do that

Hmmm I ordered 6 back in october fine. Is it just on fleabay or are they rejecting bigger the orders on their actual site too?

With the free shipping I cans see why they wouldn't want to ship too many as the cost of shipping that much weight would kill any profits. But if you were willing to pay shipping on their site I can't see why they would care how many you order as long as they had them in stock.

yeah , i'm a prime member so amazon is easy less hassle imo

After going back and looking at my invoice from them they didn't charge me for shipping. I paid tax but they shipped the 6 for free and I ordered off their site.

Now I won't say that they are still shipping them for free but the savings on orders of 6 or more from their site shouldn't be overlooked by someone interested in these heatsinks. Also ordering from them is no harder than placing an order from amazon with the benefit of knowing exactly who is sending you the product and where to contact them directly if there are any problems.

Thats my biggest problem with amazon. they will show you something and tell you there are x number of sellers and they show you whatever price, not always the cheapest. You can buy something thinking you're ordering from a trusted seller and it could end up coming from some guys garage that got bored and opened an amazon store one day. Even if you go to the right side and click on a specific seller, they are known to just change the supplier rather than contact you if the one you selected doesn't actually have the item or enough of them. SO you can think you've ordered from a reputable seller and end up receiving from a seller that if theres a problem with the product you could end up with more of a hassle than its worth to exchange it.

I generally use only amazon direct themselves , not the vendors that sell on amazon
& the A/C64's ship direct from amazon inc
anything else on amazon is like ebay i agree
but like I said NewEgg has issues & leave it at that
again I'll be mounting cobs on Saturday 2 day shipping free NewEgg can't touch that