Lumintop GT4

I agree! :smiley:

If Lumintop contact me to make dedomed leds for them I can do it just we need to agree in labour cost and they need to send me the leds on the final MCPCB-s. You can undesrstand that the shipping costs and labour will rise the final flashlight’s price by a margin. 4 leds dedoming take at least 2-3 hours continuous work on microscope making very precise moves so I think I only can make for one or max two flashlights a day to not make my eyes tired as hell… To translate that around 7-10 flashlights per month.

I’m in for at least two :slight_smile:

That’s tiring work. Would a sliced dome approach dedomed LED improvement?

Couldn’t they order dedomed LEDs on a reel? They are a manufacturer.

You can’t really dedome the 70.2. They all have to be sliced. Cree does not make HI versions, only HD with the dome.

Unless Zozz has a special technique to remove the dome, but I don’t think anyone has done this successfully.

Maxtoch has unless I’m remembering it wrong. They’ve also done a clean de-dome on the SST-40.

And slicing/dicing doesn’t take all that long once you get used to doing it. I cover the MCPCB with a copper plate that has the square cut out for the substrate, slice with a silicone greased scalpel, then dice the sides. Takes a few minutes at most. No microscope, no helping hands, no real set-up… just a couple of bare MCPCB’s under the outer edges of the copper plate to keep it sitting level on the board that has the die.

Ah, good to know thanks

That may be the only way to make this light viable if they decide to move forward with it. Even TA said the GT4 design idea is dated

I am in. reserved

Yes the 70/70.2 and the XHP35 can be de-domed cleanly…. I have done it a few times…

Here is a too closely shaved XHP70.2 that started to burn….I soaked it in a strong thinner to remove the silicone. If you right click to view/enlarge + you can see the silicone and black specs of char.

Right click to view/enlarge+

Dome on the left, clean silicone free de-dome on the right.

BLF GT XHP35HI chemically de-domed XHP35 E4’s

It can be done… :wink:

Yeah it can, I did about 15 successful dedomes, but about 8 failed, so make sure you got real sharp tools a steady hand and few extra leds on hand won’t hurt as well.

Good advise extra emitters are a must!
Slicing and Dicing isn’t de-doming it’s slicing the dome off, the 70.2 dosen’t have bond wires, pretty hard to screw that up.

Now slicing too close can cause the LED to burn, or if you polish it/sand the silicone down, sometimes causes fishers in the silicone, and it could burn, only issue I have ever seen, but if caught in time can be saved, by chemical de-doming, where patience is a virtue….that is where I screw up, pulling phosphorous off the pad, removing the silicone before it’s ready to be removed, sometimes the silicone can never be removed with out ruining the phosphorous.

The old 70’s and the XHP35’s are the toughest, they have bond wires. The SST40’s even worse.

Not to mention that some dedomed emitters fail after an unpredictably long period of time. In my experience, the harder you drive the LED, the greater chance it has to burn. It does not necessarily have to be the phosphorus or the chip itself, but even remnants of the silicone that have been fine for a year or even two might suddenly burn without any warning.

Ya man, it really sucks, out of no where…light starts to go dimmer, then you look….SMOKE! :person_facepalming:

I have learned to use a UV light and check for silicone and missing phosphorous with a 10X glass then burn them in, on the rock and then with my test light, a SD75 Lexel Narsil/Infineon FET 6 volt driver with 4 VTC5A’s everything bypassed with 18awg, at 22-23 amps, if there is any remnants of silicone, this light will seek and destroy it.

I could give a crap about the LED, it’s the Reflector getting smoked I’m pissed about! (I usually purchase extra reflectors just in case) but now it’s really not worth it anymore, been there, done that, bought a shirt, burned it……….

But it was to say the least…. All in good fun!

So you can dedome it, but it might be ruined in the process and kinda sorta might not last long when pushed hard?

I guess in my head I didn’t see it as a viable option. At least now I know dedoming is possible.

Interesting. I have one that I shaved too close and it started burning. I have a new XHP70.2 on the way that I plan on slicing a little higher, but in the meantime I could try your method, I’ve already written the burnt XHP70.2 off.

I know previously we used petrol/gas to dedome XML’s and XPG’s, but you now mention strong thinners.

- Does it specifically need to be thinners?

- Would turpentine, benzine, surgical spirits, or any other solvent work as well?

- For how long do you leave it in the thinners? When do you know it’s ready?

  • Does the silicone float off, or do you have to peel it off?

Thanks

[quote=KawiBoy1428]

Do you need a GT-Reflector? I have a spare one becaus of my aspheric-mod.

The thinner is what we have on hand at work, it will destroy 2 part epoxy paint we use on our machines, it is very strong. I kept the burnt or closely shaved LED (s) soaked and some will fall off, some will blow off, and some can be coaxed off with a wet tipped Q’Tip ….Gently…you don’t want to pull the phosphorous off with it……

[quote=Wieselflinkpro]

Thanks for the offer, But I have 2, they were in the picture I posted. Thanks again!

A GT reflector, interesting… I am about to try a prototype driver with an XHP-35 and have been considering what to put it in… my thoughts lead me to wanting to build a light from scratch but I don’t know with what reflector. Can I get a GT reflector? Would I contact Lumintop or what?

I am selling my GT70, I just got it, still has the wrapper on it. Back in the box it goes. PM me if you anyone wants it.