Looking for heatsinks

[rstar]

I thnink it would be interesting to see a pc liquid cooling concept applied to cooling LED's. Most kits are inexpensive in the grande scheme of things and allow expantion.

[mason dixon]

Would empty aluminum soda cans work? Put the leds on an aluminum bar stock and then use some thermal glue to glue a bunch of soda cans end to end(caps removed) and have a pressurized fan blow air through the soda can tube?

[StirCrazy]

check out "Steve's" LEDs. he used 1.25 square tube with 1/8th wall thickness and uses these fans on the end of the tube.
http://shop.stevesleds.com/Cooling-Fans_c11.htm they are the cooling fans from sony wega's you can get the fans cheep from him and then buy some tubing at your local metal shop.

Steve

[Ross]

Originally Posted by sphelps

Yeap or you could use a fan on each tube to make it a little easier or join the tubes with some other means. Not too many people can weld aluminum and contracting it out won't be cheap.

Loads of shops weld aluminum.

If your interested in persuing this route, pm me and I'll forward my contact list on to you.

[DiverDude]

The idea of a heatsink is to provide a large thermal mass which has as large a surface area as possible. The larger the thermal mass, the more "sinking" of heat. Most heatsinks have 'fins' since this dramatically increases the surface area exposed to ambient air. The more surface area for a given ambient temperature, the more heat that is transfered to the surrounding air.

Have you tried pricing solid aluminum plate -say, 1/2" thick ? You could make fins 1/4" deep in that with a table saw quite easily.

[StirCrazy]

Originally Posted by DiverDude

Have you tried pricing solid aluminum plate -say, 1/2" thick ? You could make fins 1/4" deep in that with a table saw quite easily.

would be cheaper ordering from the US I think

a heat sink is not as much about mass as people think, here is a def "A heat sink is a term for a component or assembly that transfers heat generated within a solid material to a fluid medium, such as air or a liquid."

a heat sink actually works on surface area not mass, the more surface area the more heat transfer. if you rely on mass then you will adsorb a lot of heat into the material but you won't be able to give it up fast enough and eventually the actual heat sink will get to hot. the fins are to increase the surface area so it can dissipate the heat faster than it builds up. fans can compensate for lower surface area, and increase efficiency as the rate of heat transfer is also a function of the difference in temp between the two mediums.

a hollow square tube 1.25 x 1.25 will disperse more heat than a solid 1.25 x 1.25 bar, because it has twice the surface area, this can even be increased further by supply fresh air with a fan which is increasing the flow over the surface also keeping the air at the surface cooler and increasing the rate of transfer.

the main reason we want to go with the single sided finned aluminum is looks. it is much easier to make it look good, but if you have some kind of enclosure in mine or are retro fitting into a hood then the square tube will work better as it will have a continuous supply of fresh air, where a fin type would be subject to the hood temp unless you vented you're hood with big fans.

the best place in Canada to find single sided finned AL, depends on where you are.. there is a couple companies in van that will bring it in.. probably charge you an arm or a leg though. same as Edmonton ect.. if you are in between like me and don't have the time or money to travel to look for it then you are stuck with metal recyclers, I have both here going to call me when they get what I am looking for in. they had some but it was double sided and I don't have a milling machine to make it single sided yet.

Steve

[reefermadness]

take your shells and put them where the sun dont shine'

[sphelps]

Anyone looking for the square tubing for heat sinks can get it at Metal Supermarkets, the location in Calgary has plenty of 1.25x1.25x0.125 6061 in stock. Cost me $80 for 16 feet.

[StirCrazy]

Originally Posted by sphelps

Anyone looking for the square tubing for heat sinks can get it at Metal Supermarkets, the location in Calgary has plenty of 1.25x1.25x0.125 6061 in stock. Cost me $80 for 16 feet.

is that what your using for yours?

I have seen 90 degree ends that that size of tubing can slide into.. just have to remember where, as that would mean you could do several runs with one good fan.

Steve

[sphelps]

Originally Posted by StirCrazy

is that what your using for yours?

I have seen 90 degree ends that that size of tubing can slide into.. just have to remember where, as that would mean you could do several runs with one good fan.

Steve

Yes I'm taking this approach, I considered running a single fan but in the end I decided just to run 4 separate tubes each driven by a single fan.