I made a video of my discussion to myself, about the P60 format.
What are everyone's thoughts about this, versus foil wrap, or a possible machined sleeve, (discussed in the video).?.
I’ve been thinking about this myself as I’ve recently bought two P60s to play with. Would some copper pipe cut to the correct dimensions be an acceptable sleeve? You may need a few layers to get the correct thickness, but you could use some arctic silver to transfer heat between the layers.
Thanks for the video! ComfyChair had a similar idea of using a copper ring to improve thermal transfer by butting it against the brass pill instead of the reflector. Here’s a link:
https://budgetlightforum.com/t/-/18148#comment-381865
So far I’ve seen the largest reduction in lumen sag by switching over to a dtp PCB, but I haven’t gotten around to testing a copper ring on the pill or on the reflector as you suggested.
That’s exactly what I was thinking. I’ll have to give it a shot.
OL, I’d be interested to see some temperature comparisons between stock, your ring idea, the copper pipe, and possibly both mods together.
My thought about P60's is what Default Username already mentioned: use a dtp copper board and ignore heatsink measures. As long as your solder doesn't melt you're good.
There is an huge emphasis here on BLF on the output improvement that dtp copper boards bring, but another great accomplishment is that by using a dtp copper board you get away fine with very bad heatsinked flashlights like p60's.
I think some kind of sleeve to make more contact with body is good for P60 drop-in. Imo nearer to led as heat source is better.
How would a DTP board help a p60? It will get the heat from the LED to the copper board, pill, and reflector faster, but it won’t have anywhere to go after that. The purpose of the suggested mods is to move the heat from the pill/reflector to the flashlight head and body.
I’m fairly new to lights, so maybe I’m missing something.
It may not be obvious why, even if you are not new to flashlights, I try to explain:
A non-dtp board has a 'narrow' heat path from led to the board/pill, so the led always has to be much hotter than the ledboard/pill to get rid of the heat as fast as it is produced (heat transfer increases -lineairly?- with temperature difference). Now, the heat transfer speed from pill to the flashlight shell is (just as with emitter to board)) dependent on 1) the quality of the heat path, but 2) is a function of the temperature difference. In a p60, with its bad heat path, the heat only gets away as fast as it is produced if the pill-reflector gets hot enough. If the ledboard is non-dtp this required high pill temperature goes together with an even much higher led-temperature. If however the board has a dtp, there is a 'wide open' heat-path from led to pill, with that same required high pill temperature this implies a led temperature not much higher than the pill, and thus better performance.
I’ve always used the SureFire/SolarForce style bodies that you dropped the pill into then tightened the head over. On those a single layer of larger soda or beer can worked as they tend to be a bit thicker. I’ve never played with a 501 style light and was surprised to see how much difference there is. It shows to have so much extra room inside that multiple layers or thicker materials are needed. One idea does come to mind on the 501’s and that is to pot the entire reflector to the head. Then screw in the brass pill as the dropin so interchangeability needed now be only the pill.
It gets heat away from the led. It is not the cure all. It holds more heat than aluminum, so the led stays cooler just a little longer, but if you were to use a FET driver with Direct Drive on high, sooner or later the solder would melt. It just takes longer. Most members would not leave the light on the highest setting long enough for that to happen.
I'm talking extremes here.
Look at 2:38 in the video. The bezel has shiny aluminum where the reflector would contact it when inserted. So there is already a direct heat path to the bezel. Perhaps some heat sink grease applied there would help. I have a WF-501B which has the same feature.
Maybe this explains why a direct-to-copper board is sufficient, because there is already a thermal path from pill to reflector to bezel and then to battery tube.
No, a dtp board in a P60 flashlight does not just delay the heating up of the led, the led really stays cooler, also over time. See my explanation above.
The shiny aluminum area is a ring that holds the lens in. It is wafer thin. There is contact, but remember, it's just spring loaded contact, as the big spring is what puts pressure on it and it does not touch the actual head itself, only the bezel. It's not a real good path, but it is a path.
Thanks for clearing that up djozz. That makes perfect sense.
OL I’ve waited a while to see you with a p60 in your hands. Finally.
On the topic of heatsinking p60’s everyone does things a little different so I won’t get into that.
As far as the sleeve for putting the dropin inside it’s a fantastic idea. The only problem is that every host is different. Even a very small discrepancy means the point of the sleeve is defeated, because you have to wrap the sleeve as well. Goldilocks effect of fitting in a host it’s either too big, too small or just right.
I’ve got a copper clad dropin that I took the outside of the reflector down almost a millimeter and added a perfect fit (lots of hand sanding) copper sleeve made from plumbing parts. It only fits one solarforce host that I made it for, another host is too big and another too loose (not by much but enough).
Unfortunately the ability to swap dropins of any make and power means that having a standard size host or dropin cavity is out of the question.
Basically it’s all about heatsinking the dropin itself and then wrapping it or making a sleeve that’s host specific. Obviously keeping the power down and having modes that don’t overdrive current too much is important too.
This is just my opinion.
I wanna see you build that sucker though. Try a solarforce host as well, the 501/2 hosts are nice because you have a head module that you can add the dropin to but solarforce is a step above. (I haven’t tried the overready and 5mega crazy hosts)
I hope you catch the p60 bug.
The last few P60s I built—I soldered a piece of 3/4” copper pipe x around 5/16’ long to the pill — after I focus the module I adjust the length so the head screws all the way on — no more outer (big) spring— With a Solar Force host I also add thin copper wrap to mate the two together further
Of course, P60 is supposed to be standardized... Yep and a check is in the mail.
I figure some form of ring could be used in any P60, done about the same way, but then again, I'm not a P60 fan either. The only Solarforce I ever had were just not high quality at all. Not consistent from part to part. These were just for Christmas, but I'm running late.
This isn't some startling invention. It was just something people might do, if they don't want to be making solder menageries, as some of us do. Or if they don't like copper tape as much as me.
I’ve done a copper pipe sleeve around the P60 reflector and whether it works a lot better or not I still like the idea of improving the contact between the reflector/pill and the head. The split ring tightens things up well but the contact area is only a thin ring so if you combined the beveled sleeve with a split design you would get a tight fit and more contact surface area. Since the brass pill is beveled as well then eliminate the spring and replace it with a split cylinder that has a beveled inside edge to fit the pill. Just about anything that improves contact between the drop in and the head will help but trying to find something easy, cheap, and sexier than a wad of aluminum foil is hard.
Ok a question for anyone competent in, oh, alloys, thermodynamics, mechanical engineering, and diffusion through metals.
This is probably a “kids do NOT try this at home” question. I don’t know what would happen. You have been warned.
Having said that — gallium metal is for sale, it’s nontoxic.
It melts in hot water. It diffuses into aluminum, creating an aluminum-gallium alloy that’s very soft:
Would a bit of this — with some carefully selected ratio of metals — make a squishy heat conductive material that would squeeze into gaps?
Someone must have thought of this already and decided not.
Or tried it and had a flashlight melt or a battery explode.
But …. I dunno. Anyone?
Once in place, how would you make it stable so it didn’t deform in use?