A tip from Old Lumens helped me, put a dab of solder on the bottom of the star before attempting reflow.
Then put a drop of solder on your iron before touching the star, the molten solder hitting the drop of solder on the star will transfer the heat you need to reflow the LED.
Then after clean off the solder off the star with dremel or sandpaper.
HTH
Keith
I give up… I need a new LED, a new star PCB and a new driver…
Where can I buy a Noctigon PCB? I couldn’t find it…
After investigation, I found out that the LED die was not reflowed properly on the star PCB… Only about 20% of the pad was covered with solder when I removed it…
That’s the first theory to explain why the LED fell off at 3A… The second theory is that I somehow shorted the LED with my thermocouple, causing a large amount of current to flow, enough to melt the solder. If I had to bet I would say first option…
I just spent 4 hours on a 4 bucks flashlight. I never think of the hassle vs cost before doing something…
Hey lagman. Sorry to hear about you tribulations. Welcome to the wonderful world of modding. Can be very frustrating and discouraging at times. But, would it really be special if it was always easy?
I believe your theory about inadequately solder on the thermal pad is likely dead on. 3 amps should not have been a issue otherwise. Your emitter is probably fine. Personally, I always buy my emitters and bases separate or reflow if already mounted. It is a very common problem.
Regarding the linked product, it is not a direct thermal path, but it isn't bad. I use those bases in applications under 5 amps. I wish they sold them for XP emitters too. I only use aluminum bases in low current applications.
If you want to continue modding and want to do high current (>5amps) XM type emitter lights, invest in some Noctigons. For XP type emitters over 3 amps, I would also recommend Noctigons unless you know of a source of cheaper non-direct thermal path copper bases.
I don't know where to suggest you buy them in Europe.
I've never tried to measure temps like you are doing. Very cool stuff you're doing with that. I'm excited to learn from your work.
Thanks for your reply. 
The emitter is dead, I overheated it and the dome fell off. The wire bondings are broken.
I think that in the future I’ll always re flow the LED if I want to increase current.
Meanwhile I’ll buy a new XM-L2 to replace the broken XP-L… Such a waste of nice LED!
Got my c12 in today, the driver is soldered to the pill. I don’t have time to play with it but I with it right now.
Just a few more images
Convoy c8, thorefire c5, ultrafire, 12
Thorfire c8, convoy c8, ultrafire c12
Thanks. After some researches I also found this which is much cheaper:
http://www.ebay.com/itm/390628986132
http://www.ebay.com/itm/321367975770
I guess it’s as good as Nogtigon?!
Nice price and also direct thermal path. Now you need some bare led XP-L and you’re in business :bigsmile:
Nice find lagman. I should have mentioned Sinkpads. I prefer them to Noctigons because they stamp up the copper under the thermal pad to make it flush with the top of the MCPCB. I haven't tried the second generation version yet.
My C2 and C12 arrived today. Well worth the $10 total but will definitely try and alter at least one to a decent driver with a better UI (I think).Tried going back to Aliexpress to honor my promise of a future order but seems like they are redoing their catalog - nothing is available.
This may sound stupid to most but......I really am not that crazy about the XPL. I understand that it is a combination of reflector PLUS Led but my beam gives like a 4-pointed star for the hot spot. Could it be that the XPL is too small for this reflector? Should I be looking for a different reflector? I almost think I should pull the XPL out and replace with an XML2 and save it for later. Keep in mind - I have ZERO experience with these C.xx lights
Another novice thing (PC for stupid me.. LOL)..can someone direct me to a thread or source that shows how to install/solder a bare emitter on to a star?
I'm with you bugsy. Not feeling love for the XP-L when it has it's dome. Reminds me of the old XM-L. I'm guessing it's the flat sides of the dome.
But I'm totally digging that it isn't supposed to lose lumens without the dome.
EDIT: If you don't have one, you can get a cheap hot air gun. Mine is as cheap as they come and I have been using it for years on all kinds of stuff. Even autobody mods. I think I'm using this solder paste at the moment. Seems to work good, even for reflowing emitters.
http://www.fasttech.com/products/0/10003546/1261003-chips-repair-tool-so...
Put some of that stuff on the contact pads of the emitter base, then put the emitter in its place on the base, then point the gun at it on low and watch the flux boil off and the emitter suction down. It's fun.
I will have throw up some before after images on my xp-l p60 drop in. 100% better without dome. But I am still in love with xml2 and xpl
This light appears to have no centering ring, the reflector just sits on a plastic decal sticker deal on top of the pill.
This allows the reflector to move around when snugging down the head. It is very hard to get the thing centered and have it stay centered.
Tried a couple centering rings but they caused the beam to have rings or to not be able to tighten the head all the way down.
Maybe a black ring would work better than the white ones and not cause rings.
Or maybe another reflector is the answer, time will tell.
Still heck of a deal, mine draw 2.65 amps on a good battery.
I know at least one..can't remember if I took both apart..have the butterfly centering ring. Haven't taken any measurements though. Still very well worth the $10 for the pair. Just not real crazy about the XPL.
ImA4Wheeler - do I have to worry about "crossing/shorting" leaeds on the LED. Seems like nobody worries about that on the videos I have seen but non allow for a real close up shots either.
You sure don't. The finish (what ever it is) between the contact pads repeals the liquid solder.
compared to c10
all the parts ,it has a nice solid pill which take a 20mm led pcb
the pill fit c10 ,the lens is the same size as well 42mm
in my case the driver , was giving almost 3 amps with a 20R and 2amps with laptop pulls.
after I replaced the wires added wiring to the springs ,the driver worked fine for 2-3 times ,after that I get really really low output from the led but the 3 modes still working.(of course for the price I will not complain)
The Courui (Big Head) indeed does not come with AR coated lens. If you want them, you’d have to get them from flashlightlens.com. A bit pricey though at around $7 each and they’re plastic, not glass, but worth it IMHO. I ended up buying two of them for my previous mod projects of de-domed XM-L2 and XP-G2 driven at around 5A each.