# Mag heatsink for the upcoming SST50 emitter.



## KillingTime (Jul 24, 2009)

Hello all,

I'm looking to get some heatsinks made for the SST-50 emitter, to fit a C \D Mag.

There's a thread going on about the emitter here:

https://www.candlepowerforums.com/posts/2985482#post2985482

It's a new emitter with the same underside footprint at the Cree XRE emitter, but you drive it at 3.6v and 5 Amps.

The emitter in the picture below is the SST-50, and the star came from DX, it's for an XRE.

http://i67.photobucket.com/albums/h316/goodproducts101/SST50-1.jpg

Because of the lack of electrical terminals on the top side, you have to (reflow?) solder the emitter to the star from the underside.

1. This is tricky. I've even got the solder paste from DX and it's still difficult to allign the emitter on the star without shorting the electrical contacts.

2. The stars available from our Chinese friends are for XRE emitters, which produce significantly less heat then the SST-50 (just over 16w) and the thermal resistance of these stars is not published.

The simple solution is to do away with the star and mount the emitter directly to the heatsink.

I was wondering how to mount an emitter in a Mag, and I had the idea below for a heatsink.

http://i67.photobucket.com/albums/h316/goodproducts101/SST50_Heatsink-1.jpg

It's essentially a regular mag heatsink that you might find on the BST boards, but instead of a raised round post for a P7 or MCE, you have a raised oblong channel the length of the heatsink. The thermal pad of the emitter mounts to the raised channel, allowing underside clearance for electrical connections.

The hollow part of the heatsink should allow for 2 - 3 shark drivers. 

How long would a heatsink like this take to make from Alu?
Tools needed (lathe \ mill).

Thanks


----------



## precisionworks (Jul 24, 2009)

> Tools needed (lathe \ mill).


Every operation, except the raised channel, is a lathe job. If you total the lathe time + the mill time, probably an hour, give or take. On a CNC machining center, about 2 minutes.


----------



## KillingTime (Jul 25, 2009)

Thanks.


----------



## sortafast (Jul 26, 2009)

Only thing I would do (speaking like I actually know what I am talking about, which odds are I don't) would be to make the wall underneath the emitter a bit thicker, and possible angle it into the walls or radius it (angling it would be easier on a manual machine). I would think with the power these will suck, they will make a good deal of heat, and I can't imagine with walls that thin that they will be able to pull all that heat off. But I am a hack that doesn't even have a college degree so take it for what its worth.


----------



## tino_ale (Jul 27, 2009)

Actually there was a thread somewhere about a thermal study for a flashlight. What I remember from it was that the thickness of the heatsink did really not play that much of a role. Also a copper heatsink would not help much to lower the emitter operating temps because eventhough the heat would be very quickly transfered from the emitter to the heatsink, it would be slower to transfer to the rest of the body and ultimately to the outside environnement.

Basically a very thick expensive copper heatsink will probably make the sink bigger but won't do much difference in flushing it out the heat out of the flashlight and in the end doesn't help much for the emitter temp compared to a relatively thin aluminium heatsink that is very well connected thermally to the rest of the flashlight...


----------

