Ideal is a relative term. A better CPU heat sink would do the trick nicely, something without heat pipes and good enough for at least 150W, 200W would be better. The problem is by that point you are usually dealing with heat pipes and that makes drilling and tapping the mounting holes almost impossible.
As a compromise the copper core stock intel heat sinks would work fairly well but man, they are hard to drill and tap. I already tried to do that to one I had.
Is it a full CPU cooler setup with a fan? How about putting the heatsink in a pan of ice cold water? Be careful what with the amps and water not mixing though voltage is low enough. Alternately inverted compressed air can?
This is a good idea, but Matt is not very knowledgeable in the subject. No offense to him. A simple copper water block, a high flow pump using 3/8” lines and a bucket of water should easily handle the heat. The question though is whether you just want to keep the emitter cool or to better simulate real world conditions of a flashlight heating up?
I like to simulate real world conditions to some extent, which is why I was never that worried about getting the biggest heatsink around. Even this test is not something I am particularly bothered about. The cold start tests show what it can do on a cold start but the hot tests are more what can be expected in the real world.
Yeah, using a giant CPU heatsink or AIO cooler should be able to get you those 10k lumens continuously
Definitely not a “normal” flashlight use case though.
I'd use some small dabs of thermal glue among the thermal paste between the heatsink and the led baseplate. This way you can use a massive high performance CPU cooler without worries. To disassemble it help yourself with some alcohol and/or white spirit, can't remember which one did the trick for me right now.
I was impressed by the luminous output of the xhp70.2 in my chimera but not by the ugly halo. That said, in real-life outdoor use the halo isn’t as obvious as on a wall and four months use with hundreds of hours at low and mid levels with a ta srk driver from lexel powered by 8x (2s4p ncr18650b) impressed me enough I haven’t replaced it. The chimera handles heat well enough that with the 70°c step down it still hasn’t stepped down from turbo at 20 minutes.
50% is quite large! Usually it’s 25% to 30%, isn’t it?
Do you think the overall result is positive or negative?
You loose lumens as well as have a smaller area the hotspot covers, but gain distance.
When I sliced my older xhp70 I found the end result was negative as I prefered the bigger hotspot and brighter output. Maybe it’s a personal preference thing?
I noticed the sliced hotspot size was pretty much the same as a xhp50.2 with the dome on.
I would speculate that a sliced dome xhp50.2 would give the same hot spot size as a xhp35 HD (with dome).
So you get 4 steps of hot spot size:
Xhp35 hi
Xhp35 HD
Xhp50.2 sliced
Xhp50.2
Xhp70.2 sliced
Xhp70.2
You start with the smallest hot spot, the lowest lumens and the lowest amp draw. Then as you go down the list the hotspot size goes up.
I wonder how the 50.2 and sliced 70.2 compare as far as amp draw for the lumens they put out?
I’ll have to sit down and crunch the numbers one of these days.