I agree. I have played with three leds soldered together, tight together and even five, but the problem is that as the beam gets out farther, black spots appear, in between the leds. De-domed would actually make that worse. The larger the total die surface, the larger the spot will be. No matter what reflector you use, you can never make an XM-L spot as small as an XR-E spot and you can’t make it as intense. The beam is going to enlarge the further away you get and as it does, it will turn more and more into separate beams, with “holes” in between.
Small die with high surface brightness. We need an XR-E on Steroids. I wish there was enough interest from Cree to make a new one, with their newer technology.
Might be easier to make a light with water cooling or something, so that an existing small die could be pushed to very high amps. Maybe even some kind of nitrogen cooling or something.
Ouchyfoot has put his finger on it (see what I did there? ;-)). Several folks predicted that kind of behavior. A 3x3 array might have a slightly more pleasing beam profile due to having something in the center. Then again the XP-E2 uses a smaller die so die-to-die spacing would be worse than what Ouchyfoot showed. [I see OL was pointing out something similar]
Mattaus, you discounted the multi-aspheric thing earlier, but you might be surprised at how effective it can be. Packhorse and Trout/Troutie-mtb on CPF both had builds with multiple ahorton aspherics. 7 Up Ahorton Aspheric Lamp | Candle Power Flashlight Forum
That said, I don’t know how one of those measures up against a single XM-L2 setup.
You could only fit 3x of those particular aspherics into the Courui anyway.
It will work ~~yes it will throw and spill some light.
It wil not work ~~it will not beat any throw records and the beam will not be pretty
That is what will happen IMHO.
Mattus I’m not sure- do you have machining capabilities?
Your best bet to get the most throw out of your multi emitter in a single reflector setup would be to either mount the emitters in a TP facing out (into the reflector) on a V facing in. It’d take some pretty serious machining but you [someone] could do it from copper so you didn’t even need MCPCB’s, just mount the emitters directly to this “adapter”. I mean just making such a piece would be a feat of engineering by its self, I can’t even invision what it would look like but I passed high school geometry with a C average lol.
Draw it on a napkin. I can’t think of any way 3 squares (with a nested circle/dome and then a square-ish die inside each one) can make a nice pattern. No matter what I draw with 3 squares… it always looks like two squares with another square sitting on top. There is no symmetry. FWIW Ouchyfoot has those two XP-G2’s very close together as is IMO.
Putting them in a triangle will have a bigger hole in the middle.
The leds are still in a triangle when straight with one offset, a lot easier to wire too.
pommie is right about the stacked bricks layout being better than the 120 degree triangle layout. Wiring actually doesn’t change at all from the offset/stack setup to the triangle setup.
Either way you have a giant deadspot instead of a die in the middle.
Does that look like something useable?
Not sure if the 0.8128mm traces are going to be able to handle the current people are going to want to push to it
lol....go to sleep for a few hours and it blows up!
OK so clearly the BLF way of doing things has gone to my head (throw more emitters and power at it) and I did not think this through properly. What I want to do is just build a compact (non-toilet plunger) thrower. But one that's brighter and throws further than what I can buy off the shelf. If I'm going to spend $200+ on a light, I'd rather build it myself and really get $200+ worth of down range light.
Cramming as many 20mm triples as I can into a Coroui head seems cool, especially if I used Noctigon triples, tight narrow optics and de-domed XPE2s. I couldn't direct drive them - no 3 cell battery pack will handle that.
Might have to think about it for a while. From what I've seen written here, multiple emitters in the base of a single reflector is not going to work the way I imagine it would. Which makes lots of sense.
I put an BLF17DD in it, did a spring bypass in the 3 springs in the tail, scraped the trace off the back of the spring pcb and soldered copper pads to carry the current from ground to springs…they had a single little 26ga or so wire carrying all the current from 3 cells! Nuts. So the hot de-domed XM-L2 U2 1D is making 1055.7 lumens off it’s 20mm Noctigon and there’s an 1/8” of copper under the aluminum shelf for good measure. (and also to shim up the entire shelf so the de-domed emiter is focused)
Edit: Is 1067M enough throw for you Matt? $42 plus cells.
