Oh, I think only on forum like this would I get some sympathy...

Flashlight Modding and DIY Parts
1

Oh, I think only on forum like this would I get some sympathy…

So, to check things out, when I ordered my ATTINY85V from Mouser, I decided to get a CREE XML2 from them as well.

So, I have a presume real CREE-XML2-U2 from Mouser, an XML2-T6 from an AliExpress and an U3 from FastTech which I consider to be presume-unknown and possibly imitations.

Using my LUX meter for a quick test, the Mouser XML-U2 appears to start slightly lower LUX than the FT XML2-U3, but the Mouser-U2 increase just pass the FT-U3. Where as, the FT started higher than the Mouser-U2 but decreases by the second to perhaps 5% below Mouser’s U2. They both are 10-15% better than the T6 from AliExpress. T6 being less than U2/U3 is expected. U2 being more than U3 is not. So, before further testing if perhaps battery was not all fully charged…

I compared them visually, I cannot discern any visual differences. Ok, seeing no visual difference with my 30x Loupe. I even “double deck” with my 10x Loupe with the 30x Loupe, I still saw no visual differences between the three. I decided to try a USB microscope my daughter has a few years ago. After a lot of fussing around, I couldn’t get it to work on my laptop.

After removing the LED from the USB microscope, I saw some gluey stuff now stuck on my Mouser Cree. No big deal, grab a Q-tip and without thinking, I grab the “GooGone” cleaner. It usually does a very decent job cleaning glue off glass. It doesn’t work on the plastic dome of the Cree too well… Well, now, the plastic dome on the Mouser Cree looks like I did a cleaning with sand paper. I cannot even see the texture of the emitter under the sandy-dome. The Mouser-U2 now puts out about 2/3 of of the FT-U3 on the LUX meter. It was > FT just hours ago.

Sometimes, I am very good in making myself a fool… Geezze… The Mouser XML2-U2 is but days old. What a waste. Damn, what a dumb thing to do… I think the “GooGone” cleaner dissolved some plastic creating a lot of visible tiny pits…

Well, I suppose I can use a couple of ATTINY85V on stand-by… That may be an excuse for me to submit another Mouser order, and as long as I am ordering, may be I should order a replacement XML2…

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Fascinating!
This seems interesting; so could Goo-Gone be used to frost the dome for a floodier light? I have some Goo-Gone at home, and some LatticeBright XM-L copies I wouldn’t mind sacrificing to the cause.

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Goo Gone will actually remove the dome quite nicely. It’s what I use for dedoming. I just pour a little into a soda bottle cap and drop the led in. The dome will float off shortly.

4

I remember RMM saying that the U3 was not what he expected because of changes by CREE.

5

It was not fine pits applying it by Q-Tip. Perhaps if you figure out a way to spray it on in fine mist. Note: The frost may not transmit light well. I recording a 1/3 drop in output.

Interesting…

I am thinking of dedoming it now. I’ve read about people doing it, but I don’t know why. Since you do that, what is the major reason for demoming?

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Increasing throw at the expense of tint and total lumen output.

If your emitter is a cooler-white tint, it might be a good candidate for a dedome, then drop it in a C8 or other host. Since the emitter isn’t any good as-is, it’s a good option to get new life from it…

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Yah, I would go ahead and pour a bottlecap full of that Goo-gone and just dedome the sucker…. I use Goof-Off, but any of those solvents will work.

You will lose some lumen, or possibly kill the emitter, but if you succeed, you have a great LED for throw!

That stinks what happened, now to make lemonade!

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Rick, you can use the mucked up LED in a flooder type light if you want, or, dedome as others suggested. If you’re dedoming, use the LED in a thrower type light, if not, be prepared for disappointment. The lumens loss is very noticeable.

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Yeah, I am accepting this LED as a lost. I will probably use this as an excuse for another Mouser order, I can use a couple more of ATTINY85V on stand-by. I have not blown one yet, but I will. (Rationalization already begun - brain modification in progress).

After I get a resupply, I will see what to do with this one. Outside of dedoming it and see what it does, I don’t have other ideas yet. I already have some lower output T6’s laying around. So I don’t really need an extra “disposable” LED.

Beside de-doming as thrower, anyone got another suggestion for what to do with an XML2-U2 with mess up lens/dome?

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well, if you don’t mind a little uglyness, I’ve put old LEDs on heatsinks and powered them by old cell phone chargers (usually in the 800mA range. You can upgrade old flashlights (or lights with xpg s for example, to give more flood).

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Goo-Gone is good stuff, so thanks for sharing another use for it!

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Based on my nose and my vast experience with thinners and solvents, I have come to the conclusion that GooGone is essentially scented cigarette lighter fluid which is essentially high-grade painter’s VM&P Naptha, a common brush-cleaning solvent. Each step away from the original makes for a huge price increase with only a nicer smell and prettier packaging as the main difference.

Something else to consider when working with thinners, solvents, and glues is that the fumes may be quite active too, and that can cause unwanted results. Plastics are particularly sensitive to fumes so if you’re cleaning vs de-doming work with strong, direct ventilation even if just a fan blowing directly on your work piece. Generally the stronger the solvent and/or the softer the plastic, the more effect fumes will have.

Some of what I’ve learned came the hard way by having to replace plastic items in my work where I either wasn’t being careful enough or didn’t know of the effect until it happened. I bought a new laminate countertop once (even though I sure didn’t want to) because of Xylene fumes- the liquid never made contact but the fumes were enough to dull the finish. Live and learn!

Phil

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Sorry to hear that. Silicone domes are extremely sensitive. You shouldn't even touch them - oils from your hands, etc. are not good. When I see marks, dust, etc. on them, all I use is 90+% isopropyl alcohol on a clean micro fiber cloth, and lightly go over it - usually works well. Isopropyl alcohol is great for lots of things - I use if for cleaning up flux, cleaning PCB boards, lots of things. It's safe on virtually everything and cleans/sterilizes.

You can get the 91% stuff at most drug stores, in 16 oz. only a couple dollars.

My vote is dedome it, but depends on the tint - can go to doubling the kcd, though a U2 I consider a bit dated now. I've been getting excellent results with U4's. Mouser and DigiKey aren't the best source to buy CREE LED's (price and choice of bin/tint) from - MtnE, IOS, Simon's AliExpress store, Cutter are all known good sources. Illumn is good, but not much choice and stock is somewhat dated.

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Goo Gone gets it’s orange scent from the d-Limonene in it. But I know it contains more ingredient(s). SawMaster says it contains VM&P Naptha too. So Goo Gone must be d-Limonene + VM&P Naptha. I wonder if that’s the secret recipe to this miracle fluid. 8)

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Yeah I’d dedome it. If you’ve already written it off as a loss, you won’t be too upset if you kill it completely. Or, you might get a perfectly dedomed emitter.

For those thinking about using this to “frost” an led, be careful. I tried doing that with sandpaper to smooth out the donut in an xhp70 beam, and it collected too much light in the “frost” and turned the dome to ash. I was able to recover that led, but only because I caught it before it damaged the phosphors.

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Hmmm…. so anyway, I tried frosting one of my counterfeit emitters like I mentioned… With a mister full of Goo-Gone, I applied a light misting to the dome. After an hour or two of sitting, no change. :expressionless:

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I’ll be interested in what happens. Maybe just at the heat an XHP produces the “frost” was a problem, but it could be fine at XM-L2 heats. I don’t know.

Btw Keltex, your sig is still my favorite on BLF. :bigsmile:

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Hmmm? You mean Don’s (User #7!) quote regarding the then-new XM-L emitters? As found in this circa-2010 review of a XP-G based P60?

That thread was active for nearly three years! But with only 36 replies.

@ the OP, So sorry you aren’t getting the sympathy you looked for in this thread. Instead, you are getting emulators who are attempting to duplicate your work intentionally! :nerd_face:

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Heat may indeed has something to do with it. Trying to recall what happened, That it “looked AOK immediate after” is something I recall clearly. With about 5 minutes of use and about 1/2 hour later is when I noticed the decreased output. LUX Meter confirmed the decrease, and then visual inspection shows tiny pits that cannot be cleaned.

Initial cleaning was goo-gone then moist (water) then alcohol. After discovering decreased output and then the clouded dome, subsequent cleaning was done with alcohol only.

The pits are big enough to be visible as a pit with 30x loupe. So subsequent cleanings did nothing.

I plan to get a replacement from Mouser since this “pitty LED” is the known-real-Cree from Mouser. Between now and then, I will remove it and check and see if possibly a dome transplant could work. I have some Latticebright XML as potential donor, but they may have a smaller dome. If dome transplant doesn’t work, I will get a pair from Mouser this time. I like having a pair so I can at least compare to see if my measurement seems reasonable by comparing it with its twin.

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I doubt you will be able to do a dome “transplant” because I can’t see a way to remove the air/space between the phosphor and the dome. I think the bottom of the dome would just reflect a lot of light and you will see even more decreased output.

Just so you know, Mouser is not the only source for genuine Cree LED’s. Very few people here buy their LED’s straight from a large supplier like Mouser.