Adventures in Modding a Surefire U2 - Confirm Version?

sween1911

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Hope all is well with the modding community! One of our dear members for whom I've done two Blackhawk Gladius mods asked me if I was up to the challenge to mess with a U2. I said sure!

Pouring over the threads from the OG U2 modder @Nitroz and trying EVERYTHING (including slightly heating the head with a propane torch with a leaky seal and almost blowing myself up) I finally got the head open with the rubber jaws in my vise and a strap wrench and cranking so hard I almost blew a blood vessel.

uIFXBKph.jpg


Now, I'm pretty sure it's the later 6V version but I'd like confirmation...

If I hit the contacts with a volt meter when the light is on, it registers over 5V
An 18650 does not fit in the tube.
It has a coolish tint.
However, when I try to identify an SSC-P4, I look for the 4 contacts at the corners, and I don't see them on this one.​

As for what to put in it, a lot of threads mention the MT-G2, but the LED itself is huge in relation to the hole in the reflector so I'm not thinking that's a good fit. I'm thinking of going with a XHP50.2.
 
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WarriorOfLight

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Gold you posted your body too :) I checked my U2 collection...

I think I was wrong with the LED identification. The LED on your U2 should be look like this:

That is a Luxeon III LED. The LED chip should be on a hexagon shaped reflective area.

If you are lucky the body is also 18650 capable. But my guess is that your U2 is a late version of the Luxeon III variant. The same body was also used for the SSC P4 Version. And this body is not 18650 capable.
 

sween1911

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Ah ha! So... that being said I should still be good with a 6V LED right? I turn it on and hit the terminals with a voltmeter and it's between 5V and 6V as I rotate the control ring.
 

WarriorOfLight

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Yes Lux III is supplied with ~6V of I remember correctly. The driver should be also a buck-boost driver. At least I read this somewhere for the Lux III. Your measurement says basically the same... :)

Maybe someone else can confirm this to be 100% sure!
 

turbodog

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Well please post what supplies you use. I've got 2 u2 lights, 1 old, 1 new, that I've thought about dropping a new emitter into.
 
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I thought it is a Luxeon V?

Either way, please post photos and details if possible. I believe a previous user Justin Case had posted a tutorial before, but went through and deleted all his photos and posts for some reason.
 

sween1911

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I thought it is a Luxeon V?

Either way, please post photos and details if possible. I believe a previous user Justin Case had posted a tutorial before, but went through and deleted all his photos and posts for some reason.

Yeah, I went down that rabbithole a few times on here....
"Post with just the reference you are looking for: [DELETED] [REDACTED] [DELETED] [YEAH...NO]"​

@turbodog Will do! I've done a few builds with the XHP50.2 and it's pretty powerful for an LED with the same die-size as an XML2. I'm thinking that would drop right in there.

@scalpel_ninja Will do on the details. I'll take a few more close-up pictures of what's in there now. I checked with a voltmeter to see the voltage in the circuit AND to indicate pos/neg before I take it apart. I've already dotted the postive side with red paint pen.
 

id30209

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Show us what it says on the body.
There were 2 types of letters (how name was printed) and you tell the difference without looking into emitter.
One was 3V and other was 6V.
 

sween1911

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Detail pics...
tM7RSTXh.jpg


RykJwqhh.jpg


I dotted the red paint pen to denote positive, but I didn't attempt any soldering yet. It was like that when I found it, honest!
That little pedestal might be a problem if I want to drop a new MCPCB on there. However, the plastic wafer moves around a little bit. I wonder if after I remove the old LED that wafer will pop off? Or... after I desolder and remove the old LED, I grind the little pedestal down flush.

pMWhmvMh.jpg



Head-end. Yes it looks like there's a plastic sleeve in there, but it won't budge. And it doesn't go through all the way to the other side, the other end has a lip where it's recessed.
Qta5llhh.jpg


Tailcap end...
VLQNtT6h.jpg


18650 definitely does not fit...
a4mcnt6h.jpg


What's the verdict @id30209?
 
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id30209

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That's 6V like mine.
Don't be fooled by the fact that 18650 doesn't go in cause some of them were made tighter than usual.
Get that XHP50 like i did and enjoy in 400lumen upgrade:clap:
 
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I was able to remove the plastic sleeve by removing all other plastic and rubber parts, then alternating soaks between boiling water and ice water with salt (slightly below freezing). This seemed to weaken the glue. I placed the body in a non-marring vise and used a 1/2 inch copper pipe with 20 mil pipe tape on one end to tap the tube out from the tailcap side. I held the pipe at an angle to allow the taped end to bind the plastic without damaging it. It took a while, but once the plastic moves and exposes one end, it's a whole lot easier to use that same pipe and tap it end to end and remove the sleeve completely.

Now I'm able to use 18650s (loaded from the head side) with plenty of room to spare.
 

turbodog

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I was able to remove the plastic sleeve by removing all other plastic and rubber parts, then alternating soaks between boiling water and ice water with salt (slightly below freezing). This seemed to weaken the glue. I placed the body in a non-marring vise and used a 1/2 inch copper pipe with 20 mil pipe tape on one end to tap the tube out from the tailcap side. I held the pipe at an angle to allow the taped end to bind the plastic without damaging it. It took a while, but once the plastic moves and exposes one end, it's a whole lot easier to use that same pipe and tap it end to end and remove the sleeve completely.

Now I'm able to use 18650s (loaded from the head side) with plenty of room to spare.

I posted a sleeve removal guide a million years ago... here it is again from memory.

Remove all items from tube, especially o-rings/plastic.

Hold palm over end.

Fill with acetone (could also try lacquer thinner)

A 6" 3.8 drive socket extension (depending on brand) will usually fit the large end into the tube.

Wiggle the extension around in circles and up/down at different spots to break the glue loose.

Might have to invert or shake the solvent around some.

Tube will come right out in 30 seconds, intake, and the solvent will take care of glue cleanup.

This method leave the tube intake for future use. Slides right back in.
 

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