Surefire U2 - opened bezel, replaced LED - again!

Recently I obtained a U2 for a very good price that not surprisingly turned out to be an abysmal performer. The tint of the LuxV was yellowish, which was fine with me, but the 1 meter lux measurement was a measly 1180, compared to two other U2s I have access to which measured 1600 and 1900, while there are reports from others whose U2s measure 2100 and almost 2400 lux.

Having an exceptionally craptacular U2 in hand, I had a choice of sending it to Surefire and asking to be made good (probably the smartest move) or putting in a WX1T emitter of which I have a couple of samples. The second option was just too interesting to resist. The biggest hurdle was opening the bezel, since there have been reports of people destroying U2s in the process, but one "chucky" fellow managed to do it without ill effect, so I followed his lead. See his thread here: U2 bezel removal

I used strips from a mountain bike tire tube, and wrapped the two parts of the bezel with that rubber, putting one end in a vise, and grabbing the other with a vise-grip. This worked well, and did not require an exceptional amount of torque.

Removing the emitter from the heatsing was not too difficult. I wicked away as much solder as I could, and lifted the leads. Prying the LED up destroyed it, and I was left with the slug sticking up. I heated the slug up with the 125 watt soldering gun, and was able to remove it from the heat sink with a needle nose plier. The rest was pretty routine. I scraped the remaining thermal epoxy from the heat sink with an exacto knife, then put a new dab of thermal epoxy down, fitted the WX1T emitter, soldered the leads, and reassembled the light.

Everything works well now. The lux measurement with the WX1T is 1480, which is a big improvement but still below the other U2's I've measured, and implies that U2s measuring near and above 2000 almost certainly have X bin LuxVs.

Sorry I don't have any pictures, but I thought people would be interested to know that replacement of the U2 LED isn't terribly difficult.

Re: Surefire U2 - opened bezel, replaced LED

Thanks for the measurements with a 'known' bin! I feel your conclusion is accurate because in this case, we are measuring lux with the same reflector configuration, so lux comparisons would be valid - a brighter LED would produce a brighter given spot in the same reflector.

So the X-bin U2s may not just be conjecture.. /ubbthreads/images/graemlins/happy14.gif

Re: Surefire U2 - opened bezel, replaced LED

would SF have actually "fixed" your U2?

Re: Surefire U2 - opened bezel, replaced LED

SF replaced the heads on two U2s I sent in for unacceptable green tint, and they don't even make any claims about that. One of those U2s measured 2100 lux, but it was way too green.

That 1180 lux U2 seems to have been a real outlier, and I'll bet it didn't even meet the downgraded 80 lumen spec that Surefire quotes for the U2. I'm pretty sure they would have swapped heads.

Re: Surefire U2 - opened bezel, replaced LED

[ QUOTE ]
so lux comparisons would be valid

[/ QUOTE ]
Well ... in this case we are talking about lights with donut holes and possibly a slightly different beam distribution, so that statement has to be taken with a grain of salt IMHO.

bernie

Re: Surefire U2 - opened bezel, replaced LED

My U2 measures 2500 lux at one meter with Meterman. bright as other xbins when doing an integrated ceiling bounce test. test was done with two surefire cells measuring 3.082V & 3.092V

WO tint and runs on 18650 at all levels. it's an early production serial number. really lucked out!!! it's a keeper /ubbthreads/images/graemlins/grin.gif

Re: Surefire U2 - opened bezel, replaced LED

Holy smokes, cy! I thought mine was bright at 2,310 lux at 1 m using an Ideal-Sperry Model 61-681. I didn't measure at the center of the beam - I searched for the hottest spot, so maybe the grain of salt is small. I didn't record cell voltages, but the SF123A's only had 2-3 minutes in the U2 on high when I measured. I haven't tested how long level 6 runs on an LG 18650, but it went just over 90 minutes on a Pila 168A before dropping to level 5, so I expect the 18650 will be fine. I need to check the 18650, though, since the Pila only maxed at 1,870.

All that to say, I'm really starting to believe those of us with good, early production models were definitely fortunate. Even with a graint of salt, I think the possibility of an x-bin is real.

Thanks for the how-to, wasBlinded! I hope I never need it, but I know where to come if I do. Glad it went well for you.

Re: Surefire U2 - opened bezel, replaced LED

My U2 reads 2290 Lux. I may be lucky, but my meter has been accused of reading high. So by comparison, same test same meter (batteries not all fresh):
my L6 reads 1,940, (semi-throw beam),
my VIP on high reads 2,600,
my L4 reads 500 (very wide beam),
my McLux TK reads 550 (wide beam),
my Lionheart reads 3,510 (throw beam),
Icarus's Tri-Lux reads 6,000 (semi wide beam),
my Aleph 1 2x123 with a TWOJ/Wiz2 reads 4,020 (ultra throw)

My Cub read 870, but I think the RCR123 cell is getting low (because I use it so much), but the same low cell in Cy's Arc LS-U-bin mod reads 1,000.

I measure at 39 inches from the LED, not the bezel, and I move the beam around until I find the absolute hot spot.

Josey

Re: Surefire U2 - opened bezel, replaced LED

Please note these are only Lux readings /ubbthreads/images/graemlins/icon15.gif which does or doesn't relate to actual lumen output.

I still maintain without access to integrating sphere, next best test is integrating ceiling bounce test. how room lights up is way more valid than lux.

that being said, measuring lux with same lights, with same meter, at same distance will give somewhat idea of a relative output.

Re: Surefire U2 - opened bezel, replaced LED

OK, more news. I'm a sick one. Bogus1 let me have one of his two WWOT emitters from a recent lot of 30 sold by Etendue. I pulled the WX1T out of the U2, and put in this WWOT. There is a minimal improvement in lux to 1600 (1480 with the WX1T), but even more interesting is that there is NO donut hole, while with the WX1T and the light's original emitter, there was one.

Anyway, its interesting that some variability in emitters themselves affects the donut hole issue in the U2.

Oh yeah, the WWOT is nice and white. There is a tiny hint of green, but I can't pick it up without a white wall and some other lights to make it show up.

Phew,

Im glad i found this thread.

I am thinking of buying a SF U2 with plans of modding it with a X-Bin.
But now i am a bit confused is the U2 equipped with a X-bin?
Is there still an issue with the donut hole in the newer versions?

Having second thoughts now hat i have been reading this post.
Dont wanna risk swapping an X-Bin for an X-Bin. :lolsign:.

I dont have any equipment to measure the lux when i get mine so i guess i will be Swapping the Led without knowing whether it is a good Bin or not.


I hate the Luxeon Lottery:scowl:.


And yes im crazy...Just want the best for my lights.:naughty:




Benny

Since you have broken the seal so to speak, you need to verify the power getting to the emitter. If you don't mind , measure the power at level 5 and 6. I'm wondering if the power was reduced as the light specs were dropped to 80lumen.

If you have two good emitter as you have used, then either there is a problem in the circuit or your meter is off relative to the rest of use. So do a p60 or p90 measurement if possible and then we can normalize the values.

Also I found measuring 1meter from the front of the light and 1 meter from the emitter to make a nice difference.

MorpheusT1 said:

...snippers...I am thinking of buying a SF U2 with plans of modding it with a X-Bin.
But now i am a bit confused is the U2 equipped with a X-bin?
Is there still an issue with the donut hole in the newer versions?

Having second thoughts now hat i have been reading this post.
Dont wanna risk swapping an X-Bin for an X-Bin. :lolsign:...end snippers!
Benny

Click to expand...

I'd seriously doubt you'd find an X bin in the U2. If you did then you would notice it as soon as you fired up the light. The X bin is extremely bright. I have a light with an X bin and my U2 doesn't even come close to the output the other light has. The output of the X bin is VERY NOTICABLE.

Here is a picture of two different lights. Neither of them is a U2. But look at the shear output of the lights. One is the very bright and rare high output Lux III; a UX1J. The other is, well, the Lux V. The X bin is very bright and you would know if you had one.

TrueBlue, what current is your X-bin being run at?

TrueBlue said:

Here is a picture of two different lights. Neither of them is a U2. But look at the shear output of the lights. One is the very bright and rare high output Lux III; a UX1J. The other is, well, the Lux V. The X bin is very bright and you would know if you had one.

Click to expand...

Hardly a fair comparison, I'd say. The images you show don't seem to have much of a target in the center. It's all periphery.

The Lux V has a much larger die area, and tends to flood more. The Lux III is going to offer more throw. There may be a lot of light coming out of that Lux III in your images, but is isn't getting caught by the foliage around the sides.

Of course, having said that, I will agree the X bin is a couple notches up from a U.

I think the pictures are a fair comparison. There are two lights, one has a brighter spill but throws equally well if not a bit more. Would centering the camera have showed anything different? No. Had the Lux V been put in any other reflector/optic the outcome would be the same. The Lux V would still be brighter.

Have you got a better picture or a better X bin emitter? Would you have preferred to be left in the dark with no pictures at all?

The Lux V is driven at 1000mA.

Not a fair comparison? Heck, when is the last time you saw a Lux V throw as far as a Lux III? That x-bin light has got to be gazongo bright to do that. I don't think the forground in the shots is the main point of interest......

Edit: Look at the tree way in the back....that's the target.

hmm, speaking of fair comparisons...

What lights are those leds in?
Obviously not the same,
the Spill dia. on the left one is much larger.

Also, you say the X bin is driven at 1000 mA, ok, what about the U bin?

Not calling you a lier,
just trying to get all the facts so the shots mean the most they can.

I have an X Bin PR head, while it is brighter then my Other 5W PR head (W Bin I think),
however, the X Bin PR head cant throw as much as my T Bin 3W head.

The X bins are nice, I have one of the early ones, and its fairly on the green side.
Though I have seen some X Bins go for prices much higher than their value in extra lumens.

~John

If you don't believe the picture then I just did a test of my U2 on high and the X bin emitter. I averaged the output of the lights using a foil lined box. Mounted on the box is an Extech 401021 Light Adapter/lux meter that is hooked to a PC interfaced multimeter. I didn't need the PC to get a reading of the three different light outputs. The XX1S output is 223% brighter than the U2. Two-hundred twenty-three percent. 2.23 times brighter than the U2 on high. That is just a single emitter, not a cluster of emitters.

The X bin is a premium Lux V emitter on overdrive. You'd expect a super output.

A little more information. The UX1J light in the picture has 79% of the output of the U2 on high. The U bin is running a Downboy 917. I didn't include a beam shot of the U2 because it has more of a flood beam and the output barely lights the tree.

I'm sorry you can't believe the light output is possible even with the picture to show otherwise.

The emitter was tested to make sure it was the brightest of the batch, the light module was carefully designed to focus the XX1S in the reflector and there are no second class converter parts. The module is mounted on the Surefire Turbo Head to concentrate the beam forward. The module was very carefully designed to show what a no holds barred Lux V light could achieve. The picture says the project was successfully completed. The light is reliable and bright. The output is so amazing even flashaholics won't believe it. I don't need to prove anything to anyone. This light was made for fun; it is a fun light. LED lights are a hobby to me and many people. This light is just pushing the LED brightness boundary a little farther.

I put the picture here in the thread to say if the U2 had an X bin emitter then you would surely notice it.

To me a light can have a spill beam and a throw beam. I enjoy both. Why not push a little harder? Why not prove that the rumor that a Lux V cannot throw a beam is wrong? Who wants to be average when you know it can be done…brighter?

TrueBlue said:

If you don't believe the picture then I just did a test of my U2 on high and the X bin emitter. I averaged the output of the lights using a foil lined box. Mounted on the box is an Extech 401021 Light Adapter/lux meter that is hooked to a PC interfaced multimeter. I didn't need the PC to get a reading of the three different light outputs. The XX1S output is 223% brighter than the U2. Two-hundred twenty-three percent. 2.23 times brighter than the U2 on high. That is just a single emitter, not a cluster of emitters.

Click to expand...

Sorry to invalidate that test but foil isn't a proper liner to simulate and IS. A tighter beam will not be diffused properly. Do a ceiling bounce in a small room for a more accurate approximation

A coating like this is necesasary http://www.engineeringtalk.com/news/pch/pch109.html