did i go overboard with this heatsink ?

what do ya think ?

Probably. For a heat sink in a mag light, you're really looking for the most contact area with the flashlight body.

I just made these last night on a friend's lathe:



5 1/32" fins, 1.35" diameter. Total contact with the flashlight body of 5 * (1/32 * pi * 1.35) = 0.66 sq inch. It's within 1/1000 of the i.d. of the flashlight tube. I can drop this into the body, and watch it slowly drop down due to the air slowly moving around the fins.

With only 6 points of contact, you might not get optimal thermal transfer to the flashlight body (unless there's a tube that extends down into the body, making better thermal contact).

actually, what you can't see is the part that's in the tube,
1&1/4" threaded into the tube, with 1/4" walls!
I most definitely have gone overboard...

yep - overkill /ubbthreads/images/graemlins/wink.gif

Over kill GOOD !!!!! grunt grunt

ACTUALLY a completely solid heatsink, like the hotlips might be even better,,, that had more mass, and even more surface area touching the lights body.

I think fins are best for outside the light,,, becuase more surface area is exposed to the outside air.

Hey Robby, that's far too little; I think you shoulda DOUBLED it! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

Those sinks I made started out from a circular heat sink, so I can't do much about the fins. But I think it's more than adequate given there's only 2.5W of heat being transferred (for my case).

93 grams of copper x 2 = 186 grams
you know what, your right, next time /ubbthreads/images/graemlins/grin.gif
guess safety shoes are in order...

Heh, heh...

Heh, if a little is good alot is better /ubbthreads/images/graemlins/grin.gif

Mine is solid and runs all the way down to the retaining clip. It fits so tight that I had a hard time getting it in the light once I put on a layer of artic alumina thermal paste...




You can never have too much heatsink /ubbthreads/images/graemlins/icon15.gif

Ok, good, i'm not sick /ubbthreads/images/graemlins/smile.gif

unnerv is sick /ubbthreads/images/graemlins/wink.gif

i think until that thing came along, i had the biggest heatsink... /ubbthreads/images/graemlins/twakfl.gif

If my flashiholism is considered a sickness, I don't want a cure /ubbthreads/images/graemlins/grin.gif

on that note, i just had to put it together...

Looks like a gigantic copper nut -- did you put the flats on deliberately to help screw it in with a wrench or something? Interesting concept if so...

Mr Bulk,
that's the idea, like a big Bolt with a hole in the center
screwed down tight with a big wrench, not much need for epoxy, especially when things heat up...

Suppose it's a little late to ask for a look at the heatsink unobscured by the flashlight body?

yea, it's a little late for this...imagine a copper bolt with an OD the same as the ID of the mag tube.
I mounted the LS on another copper bar so I could have it
sit up in the reflector.