X-ML de-doming method with 100% success?

I’m not messing with success, it’s staying bare.

Some German guys had great success with acetone to dissolve the silicone that holds the dome onto the emitter. Drop into some of that nasty stuff, wait 30-60min and pull off the dome.

I read somewhere that the adhesive holding the dome on the emitter, is the same stuff used to hold the phosphor on the die, so any use of solvents would just strip off the phosphor. These results prove otherwise though, were there any problems with the phosphor layer becoming thinner or falling off with this method? Sounds like a great way to de-dome.

Any takers on the acetone method? Coz if it works, that'd be probably the easiest method yet.

I do have extra XM-L, and I do want to dedome it - BUT, I don't have pure acetone, only some junk nail polish remover which is definitely NOT PURE. Don't know what's added in there, but very poor result if used as acetone substitute.

I wonder though, if the silicone comes off with heat though, why can't we just boil the whole star?

In my continued attempts to get a good polished surface I think I am now polishing the phosphor layer. The lux dropped to 97 kCd after last attempt. I still think a much better result will be gotten if you leave a well polished totally clear surface and a little more than 1 mm dome aboce the phosphor.

Still learning here so bear with me.

I was wrong!

I tried the trick Xandre has told us about that Andi does. Running the flashlight till it is freaking hot and then peel off the dome with my fingernail. It turns out there WAS a thin layer of dome left. I got it all off except a little around the bonding wires.

Now up to a steady 125 kCd.

I LOVE THE BLF! WOOT!

Update: Reflector position critical! Just fiddled with it and although warm now (on for 5+ mins) i get a steady 145 kCd! Woot!

Gratulations!

But @moment i think, a cookplate is better, because on some flashlights the heat is not enough.
Then heat dome, not the star.

Next i will try Chemicals. >)

You are a madman Andi. I love your work!

BTW:

Have you tried XML T6 on copper star from DX.COM? I have very very good experience with them. And good color/tint too even with dome! I wish they would bring the U3 bin on the copper star. Solid copper rocks!

And my beam is not fully "together" (sorry I forget english words when excited) at 5 meters. At 7,8 meters I measure 2690 lux meaning I have ~ 163 kCd @ 1m! YES!

Ok, you guys convinced me to go ahead & peel the rest of the dome off my T6 3C XM-L (in the craptastic SMO P60) I put the solder iron tip next to the LED, and used magnifier, tweezers, & X-acto knife to carefully peel it off. It never got hot enough to melt the solder. There is still some spooge around the bonding wires I’m not messing with, but the chip is entirely clear.
I was finally able to focus a decent hot spot with this reflector, though still ringy.
I am quite sure I left all the phosphor intact as this thing is really warm now. It looks to be 3500-4000K now, I don’t know, it’s the warmest LED I have. If I do another, I’ll start with a U2 1A or such, and hope to end up at 5000K. This color shift is fascinating; somehow the average light must be traveling through more of the phosphor(?) And this warm shift continued when removing the last .35mm of the dome too.

I heat the board directly and its firmly attached to a heat sink. I heat the board quickly with high
heat enough to melt the adhesive holding the dom and i use tweezers to pull it off. Now your using heat as well, only to a different location and completely different approach. I cant say i would suggest this but perhaps if you try this method before putting your iron to the dome itself.
I haven’t killed or scratched one LED yet ( by this method) but i have killed plenty of diodes…

I fiddled on with that reflector positioning and now I get a steady 168 kCd after 30 sec and initially when turned on it gives about 183 kCd.

Now I wait for xml 2 led with even more impatience! Muahahaha!

EDIT: Corrected some strange spelling....

I think the XML-2 is very close: I read today in an electronics magazine that Cree stated the are expecting to release a 200 lm per watt LED before the end of 2012… call me skeptical (XP-G2 is something like 160 lm / W), but ever if they manage 180 lm / Watt it is a decent step up. I think the XML-2 would be this LED. :smiley:

dedomed sky ray A0 clone 85klux initial J)
Not bad from a little light.

I think the dedome method was from Andi: I heated up the led and the pill at 4A for a few minutes, and the dome came down very easily.

200lm/W is probably assumed to be achieved at pretty low drive current and ?CRI of color renderition :slight_smile:

Wow! I actually would have expected more out of that little bastage. Considering how well it throws normally I would have guessed at least 120k+ considering the numbers other lights are pulling. I’m betting the wide base reflector reduces lux when you dedome.

If this is even remotely true, it should be easy enough to test. Without the dome of maybe RI ~1.5, the output should drop in half, which is hard to believe given the results here.

Also the RI = 3.7 is of the semi material itself (transparent to the emitted wavelengths), not phosphor layer.

The focus of the dome is evident enough from its shape and >1 RI, and comparison between CREE app note and COS curve as already noted.

Well, de-domed a XML headlamp ( ~38mm reflector), while it still goes I removed a fair bit of phosphor from two of the corners… the pictures can explain better then I can:

Before:

After:

Left to right: P60 XPG at 1A, OP reflector, XML at 800mA in 38mm SMO reflector and Trustfire X9 at 2.4A ( batteries needs recharging)

Smaller hotspot and marginally more intense, still good for all flood as the colour is even (if slightly blue) without the reflector.

I pressed the LED dome lightly against a hotplate for about 10 seconds before pushing it upwards with a knife blade…. I don’t think I let it get hot enough or perhaps I should have heated it from the underside? Going to replace the LED anyway now.