Heat-sinking a Maglite LED drop-in

[Quinn_Inuit]

I have a 4D Mag sitting around that I'm considering modifying with an LED drop-in module. I've read NewBie's review of the Mag drop-in, and it apparently is hardly heat-sinked at all.

That strikes me as both sill and a problem for the lifespan of the LED, at least if used often. Also, the heat reduces light output, and that's not cool at all.

Therefore, I've been trying to think up a way to bleed off that heat, and I think I may have something. As I understand it, the module sits in the center of the tube, isolated from the walls. Now, I know ~nothing about circuits, so I have no idea if that separation is necessary for the circuit to work or if it's just random. So I just assumed it was necessary.

Here's my plan:

1. Get some cheap, multi-stranded copper wire. I have some lying around from a Radio Shack purchase about 10 years ago. (It's not like it goes bad.
2. Wrap the strands around the module.
3. Chop off the wire so it almost, but not quite, touches the sides. (So you need somewhat less than 0.5" of wire.)
4. Then break out some electrically non-conductive thermal paste of the type used on CPUs. (Example.)
5. Use that to glue the wire to the module and to bridge the last bit of distance between the wire and the edge.

What do you think? I've never tried this before, but it sounds like it could work. I'm concerned the paste won't stick to the interior of the Mag. Are there any other glues that might? The paste just needs to bridge from the wire to the outside...some other substance can hold the paste in place if need be.

Alternatively, are there other Mag mods that might be better and easier?

 

[PCC]

You don't need to electrically isolate the copper from the battery tube as they are both negative anyway and the anodized tube will not conduct anyway.

I thought about doing something similar using soldering wick, which is braided fine copper wires but that seems excessive. The other idea I had was to make a solid aluminum tower to mount the MagLED module and have the excess heat move directly into the tower then to the body of the flashlight. I will lose the ability to quickly focus the beam, though.

All that work for an LED module that only puts out about 60 lumens? It would be far easier to get a Malkoff or build your own using a pre-made heatsink and your choice of emitter/driver board.

 

[Quinn_Inuit]

Well...I was actually kicking around the idea of mounting a different emitter on the module, too.

Do you mean you can put a Malkoff on a 4D Mag?

 

[VegasF6]

That mag led drop in is quite dated at this point. But, if you decide to use it, and decide to change the emitter, it is normally upgraded to a Seoul SSC P4 emitter. And there is, or was, at least one solution for a heatsink. Member Download built his mag tower.

Or you can purchase a more powerful drop in to begin with, from say, Terralux or Nite-ize. Kaidomain actually made a decent Cree Q5 drop in but I don't think they are available anymore.

Really, the new Rebel LED mags are so good I see no reason to even bother with a mag drop in at this point, buy a new one instead. Then turn the old one into a ROP or some other hot wire

Or something with forever runtime, like this.

If you wan't to build it just for fun, by all means do, but there are ever so much better commercial solutions at this point.

 

[VegasF6]

Finally found that tutorial.

 

[Quinn_Inuit]

Thanks for the info! I'm certainly not averse to a better solution, I just didn't realize there were any.

I'm not trying to create a truly awesome flashlight here, just something decent. I have the 4D Mag sitting around and I hate to waste it.

What's ROP? I've seen the Terralux drop-ins, but not that one.

 

[VegasF6]

Bah. I just lost a long response to this, and I refuse to type it all out again.
So, this will be a lot blunter than I originally intended.
4d sub c ROP
http://www.candlepowerforums.com/vb/showthread.php?t=222210
ROP FAQ
http://www.candlepowerforums.com/vb/showthread.php?t=120462

Downloads poorman multi lux thread
http://www.candlepowerforums.com/vb/showthread.php?t=201392
How to mag P7
http://www.candlepowerforums.com/vb/showthread.php?t=238641

old school SSC P4 mag
http://www.candlepowerforums.com/vb/showthread.php?t=167866

The gist of my last thread was this: Although it may not be cost efficient to modify your own mag, it can be rewarding in other ways. The current trend seems to be toward more and more powerful LEDs. Prior to that it was about multiple emitters to get more light as the more powerful ones didn't exist. But, prior to that were simpler times. One emitter, what was most efficient at that time. Luxeon, Seoul, and Cree. Now, in my opinion there is no reason to pursue most of the Luxeon builds. They are too old and not easily available. However, the Seoul SSC P4 is easily available and for like $4. I still like them very much, and in fact keep a 3D SSC P4 that I built in my truck all the time.

Whatever you decide to build, have fun with it, and if you need help, ask away.

 

[Quinn_Inuit]

Ouch. Sorry about the lost post.

That's good info, thanks. It gives me a lot to think about as far as where I want to take this mod. One question: how does the light output of a P7 compare to a modded Mag LED module with a different emitter soldered on (and with better heatsinking)?

 

[VegasF6]

Well, there isn't much of a comparison. A decent P7 mod will output 600-800 lumens. I am kind of guessing on the mag drop in. Maybe 60 lumens stock, and at best twice that with a SSC P4 led in the stock drop in with additional heatsink.

 

[Quinn_Inuit]

Wow. Ok, yeah, that's a huge difference.

 

[Quinn_Inuit]

Quick question: is that P7 regulated, or is the Mag drop-in module regulated? For me, reasonably constant light output is more important than high output for a couple of minutes.

 

[VegasF6]

A P7 build being regulated would of course depend on the driver chosen. I think all the ones I linked use a linear regulator.

Also, as I recall, the regulation is pretty weak on the Mag module as well. It dims as time goes on. (Although, truly that is regulation as well, but I think I know what you mean.) In addition, the Mag module uses a PTC I think to dim the LED as it heats up.

You would have to search the driver threads to find exactly what you are looking for, but the 2 highest quality sellers are www.taskled.com and The Sandwich Shoppe. Of course, quality and price are linked. (and efficiency)

 

[Quinn_Inuit]

Thanks for the info. I'm not too worried about the heat on the Mag LED module, since I have the above plan for making the heat-sinking awesome.

Adding a driver to that P7 setup might be a little complicated for me, though. I've never soldered anything before. I'm up for learning, but the P7 project just sounds a little daunting.

 

[007adan]

http://www.britelumens.com/ has very nice heatsinks for Maglites.

 

[Quinn_Inuit]

Cool. That would definitely be a good place to start looking for parts, thanks.