Big Heatsink... (pics)

Well, I tore apart a big old computer tower case and found some cool stuff in it. I found 4 12VDC fans that I could use for a spirograph-ish device. I also found a fairly large heatsink. I don't know what to do with it.

http://img511.imageshack.us/my.php?image=dscn1876ix8.jpg
It is about 5.5 inches long, 2.25 inches wide, and 1.25 inches high (~13.97cm X 5.715cm X 3.175cm)

http://img511.imageshack.us/my.php?image=dscn1875rl9.jpg
If anyobdy can put this in a laser they are building, I'd be happy with sending it to them as long as they pay the shipping. It seems to good to go to waste .


Here is all the other stuff I got:
http://img511.imageshack.us/my.php?image=dscn1874ob1.jpg


btw I posted the images' links because my pics are so huge lol.

Ooo very nice. I have way too many heatsinks as it is or I would take it

Just wondering, what makes a good heatsink? Mainly material, then design?

I'm planning on useing 2 heatsynks on the laser I am building, hoping to overdrive it to 300mw or so, those computer heatsyncs are fairly good for that.

Just finished cleaning as much of that crap out of it as I could... that computer probably wasn't cleaned in like 10 years lol.

Yea material and the design.

KK


Yea so if anybody wants to use it, just tell me and I'll send it over. You just pay shipping.
Otherwise I'll probably just throw it away or put it somewhere and forget about it lol.

The whole design behind a heatsink is essentially pretty simple. Find a material that has excellent thermal transfer characteristics and move the heat throughout a large mass for dissapation. The materials that make excellent heatsinks are of course
1.silver. Being the best
2.Copper
3.aluminum
then various other metals blah, blah, blah. spreading that heat along the entire surface is all well and fine, however being able to spread it over more surface is even better. You can see examples of excellent heatsinks by Zalman. They use extremely thin (trust me it's thin I've cut myself on the fins) copper and then move air over that mass to more readily move the heat off of that metal.

Next thing to take into consideration is the joint between your thing you wanna cool and the heatsink. Since in life there is no "perfect" surfaces are never perfectly smooth. Putting two not so perfect flat surfaces together leaves you with thousands of microscopic pits and grooves and valleys. These prevent the heat from wicking to the heatsink and moving it away from the material needing to be cooled. So we use Thermal paste to fill in those valleys and pits. (think of it as a jar of marbles. Your gonna have spaces. Those spaces get filled with Water and there's no more valleys or pits (spaces between the marbles) Arctic silver makes a thermal compound that is Silver in a paste. Since silver is the best for wicking heat it fills those groove perfectly and we transfer teh heat to the heatsink more efficiently.

There is your basic in heatsinks.

well you can drill them and put your modules in them and add a fan to keep them cooool

Originally, it had the two fans in the last picture, held in a plastic housing, attached to the top.