P60 Copper Wrapping Measurements

The P60 drop-in is faulty by design, as far as heat transferral is concerned. Crikey, all those bloody drop-ins are designed very poorly!

Have you ever taken apart one of those? No offense, as I do know a lot of you probably have. That brass pill which screws into the aluminium reflector, well, to be honest - I couldn’t think of a design more flimsily. Subsequently, I’d add as much copper to the pill as only possible; press-fit, then add a thin line of solder, just to make sure.

Next comes the design itself: Heat, for that matter, is mostly drawn off by the wrapped aluminium reflector to the head of the torch. Which, in turn, is not the part where the heat actually builds up - that would be the junction point between the emitter star and the pill, or more comprehensively, the pill by itself.

Now, you’d still have to overcome that terribly bad barrier of threads between the pill and the reflector, to effectively draw off the excess heat.

Think about that, sometime. Standard LED P60s are awful to heatsink properly.

Oh, just to add one more thought - a thought, really, an idea, nothing proven by myself, so don’t club me to death if I should be wrong:

Copper is only as good as the alloy it will come as. Meaning: Pure (chemically pure!) copper = excellent, use it if you can get your hands on it!; industrial-grade-copper (a.k.a. “what-the-machine-shops-with-all-their-fancy-CNC-lathes-usually-have-piled-as-bar-stock”) = save your effort and take your commercially available aluminium bar stock, as it can be machined much more easily, and transfers heat at the same rate as a generic copper alloy.

please take this into consideration as well.

Oh, on a side note: Of course!!! I do use copper with a pill rather than aluminium - just for the sole factor that soldering copper to brass is SOO incredibly easy, compared to soldering aluminium to brass.




your best bet would be a conically shaped liner bushing, and both the pill and reflector re-worked on a lathe to match that conical shape of the bushing, then hand-lap, then press-fit everything together. Sounds like a lot of work? It surely is, at least for me. Angles of any kind I have always found terrible, be it on 3ds max, AutoCAD, Nemetschek Allplan CAD and even by hand.

As I understand it if you specify c101 when ordering a part at a machine shop then it will be made of 99.9% pure copper.

scaru, I’m looking for a source myself. Things aren’t as easy in continental Europe as they are in the US, or in the UK.
May not even legally hunt down mice on my attic or in the garden with an air rifle over here.

I'm pretty sure this company ships to europe.

oh my, intl’ shipping - I’d be horray about it, if the suspension parts for my 1967 Mercury hadn’t cost so much already!

ta, bookmarked for next month! :slight_smile:

I wonder what is the point in wrapping the reflector with foil. I tend to wrap the bottom 5 mm of the reflector and the base of the pill but the spring gets in the way. Sometimes I remove the spring as it doesn’t serve any purpose as far as I can tell.

Yeah, thanx for sharing BetweenRides!

the larger spring tightens the reflector to the pill i am pretty sure if u take it out and play with it :slight_smile:

I also got 50c with aluminum foil. I got about 43c with no Aluminum foil showing the foil does indeed help a good bit. Don’t see any benefit using copper. Also, I didn’t see your temp with no foil?


Ha! Great idea! How many wrappings did you have to do with aluminum? Wikipedia says that standard aluminum foil is 0.6 mils thick and heavy-duty is 0.9 mils thick so you'd have to wrap 3x-6x times the 3 mil thick copper. Also, the aluminum might be too thin and rip as you tried to force it into the body. Did you have this problem?

BTW, the OP lists the full temperature rise of both unjacketed and copper-jacketed versions in the graph. It looks like 44C 46C to me.

I’ve been using 24 ounce Monster cans as they are about twice as thick, often needing only 3 layers or less to get a tight fit. Also being stiffer due to thickness the pills outer spring dosen’t get in the way and can be left on.

I hope you have fun here, lensmanmark!

C110 copper is 99.9% pure. C101 copper is 99.99% pure. That 0.09% difference just about doubles the cost at an increase in thermal performance of about 5%. Hardly worth the added cost.

Tapered copper pill?

It was not made for the Surefire lights so the taper is slightly off, but, you get the idea.

I’ve wrapped with copper and aluminum, both work well and I can’t tell a difference. The most crucial part is the attachment of the Led to the board and/or the pill. After that the pill to the body seems a distant 2nd. I’m looking at a very small focal point of the Led of only a few square mm’s. The surface area of the outer pill to the body is much greater either metal is going to move more heat than can be transferred from the Led bottleneck. Of the two metals copper is much more malleable fitting with less fuss. Aluminum is just free from an old can and requires just a little more work. The exception is if I’m working a quad at 5.6 amps then I’m using copper, aluminum for everything else.

All the pics in the OP are saying deleted or moved?? Can this be fixed? Thanx!!

Replace the bloody brass pill with a copper pipe cap and build it up from there with copper out to the host and maximize the surface contact area between the drop in and the host.

Just to de-rail the thread slightly, that’s the first mention of E.E.“Doc” Smith that I’ve seen for years. I was a fan of the ‘Skylark’ series.
Back to wrapping P60 drop-ins. I use Slug Tape, adhesive backed copper foil that is also used to screen pick-ups on electric guitars. I’m sure that the adhesive does something horrific to the heat transfer but try wrapping your finger with it and hold a lighted match underneath it, insulate much? :bigsmile:

Fixed :)

Any reason to use foil instead of copper tape? I have some very thin 1/2” wide copper tape which fits just about perfectly on my malkoff and lumensfactory drop ins. Will the adhesive create an insulating barrier?

Yes, remove the adhesive with thinner, nail polish remover or a strong alcohol….