It seems good, felt cool, until I felt something not quite right about the temperature, so I decided to take apart it to examine.
The LED doesn’t have a proper heatsinking capability, only about 10-20% contact with the base, thats why it stays cool on hold (while the LED boiling over time)
So obviously this cannot be let it go and use like this, looking resources to custom make an aluminium(or copper) base for it.
The problem here is that I dunno how to do one, nor I have any tools for it. (I only have drills, saw, etc. No taps, die, dremel, etc) So my main problem is how to make the thread perfectly (or at least I could fit, screw in securely) thus I need some enlightenment from the forum.
Would really appreciate if people could guide me to this modification (first timer). Would be nice if there is also guide to make one, such as how to design a nice heat transfer base for the LED.
I have a lot of these. That design is not a problem really, as long as the amperage is reasonable and the base is constantly under some pressure.
I’ve measured light output for 2.8A using this design - the output doesn’t sag very much at all for 5 minutes. If thermal management is bad, output will drop within first 30second like crazy.
Have you tested tailcap amps? Likely than not it’s about 2A-ish. If you can confirm that, then my advice to you would be to dab some thermal grease, reassemble (make adjustment so the pill don’t get screwed in too much) and enjoy the light.
I agree with Pulsar13 if it is under driven like most stock lights. If you want, you can do the following:
Wrap aluminum or copper foil around the pill threads. That will tighten up the thread contact.
Pound one or two copper coins or slugs until it reaches a diameter that you can press into the hollow section of the pill. Ideally, you would want to file/sand them flat for better contact with the emitter base.
The aluminum emitter base is the biggest bottleneck on most lights. Probably the best thing you could do is get copper emitter base (Sinkpad or Noctigon).
I have re-done a bunch of these hollow C8 pills by stacking 4 pennies inside the pill (I use Canadian pennies, and the 1980-1981 pennies are exactly the right diameter, along with being 98% copper). Anyway - I stack them inside the pill and sandwich solder paste between each penny. I use an old 20mm aluminum star to hold the penny stack so it is aligned to the top seat of the pill (the seat that the led will sit on). Then I get out the torch and melt it all together. The solder will join all the pennies together in a nice, flat stack - but it will not join very well to the aluminum pill - so you end up with a nice, press-fit slug of copper and solder. I do find I have to "press" down on the stack at the end of the soldering, to ensure it stays flat and snug. I typically use a 17mm driver, so I solder a driver ring eg., (https://www.fasttech.com/p/1250001) onto the bottom of the penny stack. Then just drill your wire holes through the slug and you have a nice, heavy heatsink with a nice, heavy plate for your star to sit on.
haha, regretly said, the tailcap current is low compared to yours. Roughly about 1.2A (and I want to do something about that, thus wanted to make better heat transfer)
I have a 501B XML-T6 torch with about 1.5 tailcap current, but its heat dissipation is alot higher, and it managed to make my emitter degrade slightly due to overheat (LED emitter dimmed compare to before) in matter of 5 minutes of still air. (hot to hold, estimation would be about 50-60 degree celsius)
My guess is that the the cheap C8 is using linear driver (thus driving the LED at same current) while 501B using Buck driver (thus alot higher output, roughly[guess] 3.15V 1.9A on LED)
* Another question out of topic: what would happen to a torch overheated ? if not too severe, like in my case. Damage to LED is inevitable, what about the driver ?
nice idea, never thought about reuse this copper penny this way (my country, Malaysia have 1sen that is Copper clad steel cannot be used anymore)
Will try to do so, after cleaning them off.
A question, do you put thermal compound before soldering, in between pennies ? if so, will the compound ooze out if you drilled it ? (slimy juice ~)
I got the ThorFire one, about the same deal…
Hollow pill and I guess 1.5 Ampère max, 5 mode, cool white XML.
We should have bought the Convoy C8 I guess…
But I put an alu washer (some 0.7 mm I guess) between LED base and reflector, adding the reflector as heat sink.
It happens to self centre nicely though.
No heat problems anymore.
Maybe it’ll work for you too.
I wonder if expoxying the star to the pill…filling any holes, the potting the pill with silicon (under the star, say 1/8” filled up under it) wouldn’t help?
Best bet is to get a copper star under the emitter, stock aluminum stars are the worst…I lost an emitter today because of a stupid copper star
