Surefire U2 Ultra XP-G2 mod

Nitroz

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I recently modded this U2 with an XP-G2 emitter, 3D tint(5000k). The results versus the original P4 Seoul are so much better. To me the stock LED is weak and has a very cool blue tint.

Enough rambling and on with the pictures.

Removed the control ring in preparation for heating.
20130328154739.jpg


Head separated.
20130328155830.jpg


Stock LED removed, and cleaned for new emitter.
20130328164604.jpg


XP-G2 installed.
20130329143153.jpg


Light re-assembled
20130329144802.jpg



20130329143534.jpg
 

Nitroz

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It makes me wanna open mine up, How's the Beam compared to the SSC P4?

It's night and day! Here's some crappy cell phone pic of the XP-G2. The tint is so much better.
This is level 3
20130331184709.jpg


This is full power
20130331184631.jpg
 

Nitroz

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Very nice mod on a beautiful host... makes me want an U2 now...
Thanks! All I can say is, do it!

The only thing that would be nice is for the high to be 1.5 amps instead of about 620 mA at the tailcap. It is still a huge improvement over the P4 Seoul.
 

Tana

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Thanks! All I can say is, do it!

The only thing that would be nice is for the high to be 1.5 amps instead of about 620 mA at the tailcap. It is still a huge improvement over the P4 Seoul.

620mA at the tailcap with Surefire's buck driver would give 1A to the LED... so OTF should be about 300 lumens with XPG2 R5... and it will run for 2 hours that way... 1.5A at the tailcap would seriously overdrive the XPG2...
 

Nitroz

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620mA at the tailcap with Surefire's buck driver would give 1A to the LED... so OTF should be about 300 lumens with XPG2 R5... and it will run for 2 hours that way... 1.5A at the tailcap would seriously overdrive the XPG2...

I guess I should have made clear that I would like to see the 1.5A at the emitter and not the tailcap. With 6 modes though I think a high should be just that. Just dreaming. :)
 

Tana

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I guess I should have made clear that I would like to see the 1.5A at the emitter and not the tailcap. With 6 modes though I think a high should be just that. Just dreaming. :)

Oh, that's easy... just swap the driver as well... :devil:
 

cubebike

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Nice! I have U2 sitting on the shelf collecting dust at this moment! I never modded any flashlight before! Might give it a try! Looks like the XPG2 die a bit too small for the reflector ? Should I go for XML2? I have no idea about the current, driver and Vf stuff like that! Looking forward for some instructions !!
 

Tana

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Nice! I have U2 sitting on the shelf collecting dust at this moment! I never modded any flashlight before! Might give it a try! Looks like the XPG2 die a bit too small for the reflector ? Should I go for XML2? I have no idea about the current, driver and Vf stuff like that! Looking forward for some instructions !!

You could go with XML2... especially shaved or dedomed for smaller hotspot and better throw... but XPG2 is ideal with stock driver, imho, just like what Nitroz did... and you get better throw, compared to Malkoff M61 for example, because of bigger reflector...

That beamshot looks really nice... definitely a great EDC now...
 

Justin Case

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620mA at the tailcap with Surefire's buck driver would give 1A to the LED... so OTF should be about 300 lumens with XPG2 R5... and it will run for 2 hours that way... 1.5A at the tailcap would seriously overdrive the XPG2...
I measured 915mA drive in my U2A that I mod'ed.
 

Tana

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I measured 915mA drive in my U2A that I mod'ed.

So two different drivers used... (I doubt that different emitters would create such a difference with the same driver)... Did U2A have P4 Seoul emitter as well ???

So basically, you have what Nitroz wished for...
 

Justin Case

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So two different drivers used... (I doubt that different emitters would create such a difference with the same driver)... Did U2A have P4 Seoul emitter as well ???

So basically, you have what Nitroz wished for...

No, Nitroz wanted 1.5A drive. I measured 915mA drive. Yes, CPF nomenclature for the U2A means the Seoul P4 version, not the Lux V boost driver model.

You apparently are confusing tail current draw with drive current.

FYI, swapping out the driver looks like a non-trivial task. The driver is a two board design, with the bottom board implementing Hall Effect sensors, which provide for the multimode switching through the selector ring. I don't think you'll find an off the shelf replacement for that driver if you want to retain multimode control through the ring.
 

Nitroz

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You apparently are confusing tail current draw with drive current.

FYI, swapping out the driver looks like a non-trivial task. The driver is a two board design, with the bottom board implementing Hall Effect sensors, which provide for the multimode switching through the selector ring. I don't think you'll find an off the shelf replacement for that driver if you want to retain multimode control through the ring.

920 is what I measured on that U2. As far as changing the driver, no way! It's a great design.

awesome work! so you didn't need to put any copper shims under the XP-G2 or anything?

No shim. The beam looks much better than the P4 so I left it at that.
 

Justin Case

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920 is what I measured on that U2. As far as changing the driver, no way! It's a great design. No shim. The beam looks much better than the P4 so I left it at that.
Thanks for the confirmation that the drive current is in the low 900mA range. I found that if you use a 2mm thick MCPCB (such as the 10mm diam Cutter boards) under an XP-G or XM-L, then you don't need a shim to get the LED die to the right focus height. But if you use an 8mm diam round MCPCB, those are typically 0.8mm-1mm thick and you do need a shim to raise up the LED die.
 

Nitroz

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Thanks for the confirmation that the drive current is in the low 900mA range. I found that if you use a 2mm thick MCPCB (such as the 10mm diam Cutter boards) under an XP-G or XM-L, then you don't need a shim to get the LED die to the right focus height. But if you use an 8mm diam round MCPCB, those are typically 0.8mm-1mm thick and you do need a shim to raise up the LED die.

It was a 10mm round, 2mm thick board I used and dremeled it down to 8mm round. That looks to me like the sweet spot.
 

Redhat703

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This is a beautiful mod! It makes me want to mod mine as I have 3 U2A's. I have a question: does the Nichia 219 LED fit in?
 

Tana

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No, Nitroz wanted 1.5A drive. I measured 915mA drive. Yes, CPF nomenclature for the U2A means the Seoul P4 version, not the Lux V boost driver model.

You apparently are confusing tail current draw with drive current.

FYI, swapping out the driver looks like a non-trivial task. The driver is a two board design, with the bottom board implementing Hall Effect sensors, which provide for the multimode switching through the selector ring. I don't think you'll find an off the shelf replacement for that driver if you want to retain multimode control through the ring.


:)

I presumed you measured at the tailcap like Nitroz mentioned in post #5...

This makes more sense...

With selector ring available, a full output current for XPG2 or Nichia219 at 1.5A would seem much much better, I agree... And I did joke about swapping a driver, I've seen a pic of internals of U2 and it's not just an ordinary driver inside... :)
 
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Nitroz

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This is a beautiful mod! It makes me want to mod mine as I have 3 U2A's. I have a question: does the Nichia 219 LED fit in?

The Nichia will fit since it can use the same board as the XPG2. Now the only thing is what the beam looks like at the 2mm like the XPG2.

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
 
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