How to heatsink a Fatman??

[Mark_Paulus]

Here's my setup:

I have a fatman running 3 LuxIII. LuxIII are mounted on a ModaMag PTS,
and it's mounted into a Craftsman 2D Toollight.
Light is powered via 2 Li-Ion (either AW C cells or 18650. Have used both successfully).

My problem is, is that after using it for a little over a year on my bike as my bike light, I have apparently burned out part of the Fatman. Georges80 was good enough to repair it, but he mentioned that I am probably pulling too much current with 3 LUXIII for a bare fatman, and I need to investigate heatsinking it.

So, I'm not exactly clear on what/how I should heatsink this thing.

Oh yeah, I am planning on upgrading(??) the LEDs to Cree P4s. They are on order. Will my current draw / heatsink requirements change by changing the LEDs??

Thanks.

 

[LED Zeppelin]

I'm not familiar with the Craftsman 2D light, but here is how I made a heatsink for a Shark from bent 1/16" alum in a 2C Mag:



Be sure to skim coat the sink with epoxy and let it cure before epoxying the converter. Otherwise some contacts may ground out on the sink.

I've also seen someone use a braided copper strap as the thermal path. This would allow more flexibility in positioning if the interior space is limited.

An easier method would be to simply epoxy the converter to the tube, but with the larger dia. Fatman, you'll need quite a bit of epoxy and it wouldn't transfer heat as efficiently.

 

[wintermute]

I'm not familiar with the Craftsman 2D light, but here is how I made a heatsink for a Shark from bent 1/16" alum in a 2C Mag:



Be sure to skim coat the sink with epoxy and let it cure before epoxying the converter. Otherwise some contacts may ground out on the sink.

I've also seen someone use a braided copper strap as the thermal path. This would allow more flexibility in positioning if the interior space is limited.

An easier method would be to simply epoxy the converter to the tube, but with the larger dia. Fatman, you'll need quite a bit of epoxy and it wouldn't transfer heat as efficiently.

So small - so genius. Someone should make those to sell on the board. Great little ingenuity

 

[milkyspit]

Zep, gotta say, that's a great idea. Kudos! :bow:

 

[Nitroz]

Gotta love that nice clean work, way to go Zepplin!

 

[wintermute]

You know, the only problem with that little heatsink, one which you kinda solved the other day by making that post. The fact that it is on the inside and no one would ever see it otherwise. Post your cool stuff, in all of it's glory here on CPF. Let other people see the handy work - you could have missed out on a lot of free praise. Executives pay good money for people to give them praise everyday...with a little ingenuity, you can get it for free here on CPF.

But, you know I'm gonna steal that right...

Just letting you know ahead of time.

 

[LED Zeppelin]

Wow, thanks for all the kind words guys.

Just finished a Penta-Q4 in a FM D Mag host running the same Shark/pot setup powered by 3 X 17670. I'll post the light here in a new thread soon.

The Shark heatsink is the same principle, but made to fit the larger D tube. The extra room makes it much easier to mount and solder the innards.

 

[Mark_Paulus]

Thanks for the answers. I think I have some ideas, perhaps using some stacked Aluminum 1/4" washers I found @ Home Depot.