# Princeton Tec EOS and XP-G,....



## Tidra (Nov 12, 2009)

Did anyone try to mod the PT EOS with Cree XP-G???

LP
Iztok


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## adirondackdestroyer (Nov 12, 2009)

Tidra said:


> Did anyone try to mod the PT EOS with Cree XP-G???
> 
> LP
> Iztok



I haven't heard about anyone doing this, but I can imagine it would be pretty damn sweet if it worked out well.


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## jar3ds (Nov 12, 2009)

I was about to... but now can't find R5 XP-G's... Should be a very easy mod w/ a little reflector adjustment (for those who already are using reflectors)


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## Tidra (Nov 12, 2009)

If you find XP-G R5 emiters please let me know,... I am looking too


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## greenLED (Nov 12, 2009)

Tidra said:


> Did anyone try to mod the PT EOS with Cree XP-G???


Considering the size of the die, the Rebel version of the Eos might be best (thinking optics here). Not sure what the brightness increase might be compared to stock, though.

OTOH, anything you can put in place of a stock Luxeon Eos will be a lot brighter.


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## CyberCT (Jan 16, 2012)

Sorry to bring this up from the dead, but I got the Princeton Tec EOS as a gift and love the headlamp but the beam is way too blue for me. Where can I get a neutral XPG-R5 on a 20mm star? I can and have bought these neutral XPG-R5s with 16mm base for my Rayovac lantern project but can anyone tell me if it will work the same?

http://www.shiningbeam.com/servlet/the-24/**NEW**-Cree-XP-dsh-G-R4/Detail

BTW I followed a 24 minute video posted online to mod it with an XPG and the damn temperature sensor was epoxyd to the stock LED. I ended up breaking the temperature sensor trying to get it off, but the light still works.

EDIT: I found a 20mm star, but it's an r2 neutral XPG neutral white.
http://www.ledsupply.com/creexpg-nw118.php


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## robostudent5000 (Jan 17, 2012)

if your main concern is the color, just get a neutral Rebel from Ledsupply and do a direct swap. that'll be the easiest. the Rebel is a good emitter. no point in using an XPG when the max drive current on a Eos is 300mA.

if you want the XPG, check out this thread. it shows nicely the cut you have to make in the optic holder to fit the XPG. the OP of that thread got his XPG's from Cutter.

if you use the 16mm star you have, you might have to make some cuts in the optic holder to make room for the star's solder pads and maybe get a little creative with the wires.

your light will work fine without the temp sensor. 

i've used those R2 XPG's from Ledsupply in a Eos. the color was really nice, but there was minimal output difference compared to a stock Eos 70.



CyberCT said:


> Sorry to bring this up from the dead, but I got the Princeton Tec EOS as a gift and love the headlamp but the beam is way too blue for me. Where can I get a neutral XPG-R5 on a 20mm star? I can and have bought these neutral XPG-R5s with 16mm base for my Rayovac lantern project but can anyone tell me if it will work the same?
> 
> http://www.shiningbeam.com/servlet/the-24/**NEW**-Cree-XP-dsh-G-R4/Detail
> 
> ...


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## gcbryan (Jan 17, 2012)

You could also just put a light amber filter on it and take care of the excessive blue.


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## CyberCT (Jan 17, 2012)

Well my mod is complete. Success!! Much warmer than the stock LED. In fact, maybe a tad too warm. Unlike most people I hate warm white but I also hate the bluish tint too. My TK41 and TK35 on the turbo modes are about the perfect tint, maybe just a TAD too cool, but barely. I feel the neutral white is a tad warm but I can certainly live with this over the crappy stock blue. 

The beam pattern sucks. The good news is I never intended this gift to be a thrower. I want it to be floody. If I want something more thowey I would use my regular Fenix flashlights. This EOS is intended for caving. So I might just layer tape over the reflector until the beam pattern isn't bad and the beam is more floody, then reinstall the unit. I didn't use my Arctic Silver epoxy yet, but the tension seems to be holding the copper penny in place which is right under my 16mm LED, snug against the back and black housing. 

On the workbench I left the unit on high with the LED under the copper penny and after a half hour the penny was barely warm. I'm going to leave my EOS now completely assembled on high for about an hour then take it apart real quick to make sure it's not too hot. My temperature sensor got busted during the uninstallation of the stock LED so I just want to make sure.

On a ceiling bounce test, it's pretty bright which is pleasantly surprising. I can see everything in my room with ease. I really like this EOS unit. I have bought only Fenix lights over the last two years mostly because of their quality and true IPX-8 waterproof rating. I've taken them snorkeling at night with friends many times and they have never leaked or failed once. Snorkeling is pretty awesome BTW even if it is freshwater and only eels, carp, turtles, etc are there.


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## robostudent5000 (Jan 17, 2012)

is the LED perfectly centered, cuz that can make a big difference.

which version of Eos do you have? 



CyberCT said:


> The beam pattern sucks.


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## CyberCT (Jan 18, 2012)

I'm not sure which one I have. The black plastic holder was the older type I know that.

I ended up putting 3 layers of clear electrical tape over the reflector. Then reassembling everything. WOW what a difference. Nothing but pure flood. If you look at the light itself from the outside you can see a few bubbles in the 3 layers of tape. I tried many times over for that not to happend but no success. I could get that frost type spray which I might do. However the beam pattern is perfect with absolutely no artifacts. The output did diminish a little but that's OK. This will be for caving in small areas and once I get to areas I can stand or are bigger I'll just use my TK35.


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## robostudent5000 (Jan 18, 2012)

what did the original LED look like. this is a Lux Ihttp://lumensreview.com/uploads/SS-2010.04.11-20.02.27.jpg. this is a Rebelhttp://farm5.static.flickr.com/4129/5047849305_950cb31c33.jpg. 

if it was the Lux I, then the beam will not look clean with an XPG unless you adjust the focal length from the LED to the optic. if that's what you have, you are better off finding a reflector that fits the holder and ditching the stock optic. a reflector will give you a wider and floodier beam and won't require you to use 3 layers of tape to get the results you want.



CyberCT said:


> I'm not sure which one I have.


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## CyberCT (Jan 18, 2012)

I had the lux 1


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## robostudent5000 (Jan 18, 2012)

that explains the crappy beam. i think the best option is to find a reflector that will work with the XPG... but finding one might not be easy. and you would still then have to mod the optic holder.

one thing you can do to make things work better with the stock optic is to to raise the XPG. to do this, get a blank 20mm star, epoxy the 16mm XPG to the blank star, cut out the centering device on the optic holder, manually center the XPG inside the optic holder, then epoxy the stars to the optic holder. this should raise the XPG far enough to achieve the correct focal length with the stock optic. 

it would be the same idea as what Szemhazai applied for his Tikka XP mod shown herehttp://www.candlepowerforums.com/vb...)-(xp-g-mod)&p=3441963&viewfull=1#post3441963.

for the blank 20mm star, you can just take the stock Lux I star, desolder the Lux I, flip the star so the blank side faces up, and epoxy the 16mm XPG to the blank side. the original 20mm star is thicker than most stars you can buy and will work better than anything else probably.



CyberCT said:


> I had the lux 1


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## CyberCT (Jan 18, 2012)

robostudent5000 said:


> that explains the crappy beam. i think the best option is to find a reflector that will work with the XPG... but finding one might not be easy. and you would still then have to mod the optic holder.
> 
> one thing you can do to make things work better with the stock optic is to to raise the XPG. to do this, get a blank 20mm star, epoxy the 16mm XPG to the blank star, cut out the centering device on the optic holder, manually center the XPG inside the optic holder, then epoxy the stars to the optic holder. this should raise the XPG far enough to achieve the correct focal length with the stock optic.
> 
> ...



That's a pretty good idea. I'll give it a shot later when I get home.


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## CyberCT (Jan 18, 2012)

Well I did the mod. But because the 16mm star is there on top of the filed down 20mm star, it still wouldn't fit right. If the LED and small heatsink fit in-between the open space of the black holder of the EOS (like the user had in the link) then it would have fit perfectly. 

No matter though because while a snug not 100% secure fit, the 16mm LED star is now secured and epoxied in the middle of the 20mm star. I lined up with the EOS lens while it was drying. I reassembed everything but the beam center was still pretty bad with artifacts. I also took the 3 layers of tape off and put just one layer of tape on the lens. Then reassembled everything. The light output is a little better than the 3 layers of tape I previously had on and the beam is still diffused enough where it's floody and you can't see any artifacts in the beam. I'm pretty happy with what I have now.

I just charged three AAA eneloops and put them in. My goal was to see how long the high mode would last before stepping down to the next level, and how hot the unit got with the 20mm star epoxied to the 16mm star. Well the unit is barely warm to the touch and it has been 2 hours and 41 minutes so far and the unit is still on the highest mode. Hasn't stepped down yet.


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## robostudent5000 (Jan 19, 2012)

did you cut out the centering bracket in the middle of the optic holder? the raised XPG won't fit unless you basically turn the optic holder into a hollow tube. 

centering the LED manually can be a tough task. even a fraction of a mm can make a big difference in the beam so it's not uncommon to end up with a few rings when doing things manually. you probably did a good job if you have that one layer of tape on there and are happy with the results.

a Eos should run for a tick over 3 hours on high on Eneloops.



CyberCT said:


> Well I did the mod. But because the 16mm star is there on top of the filed down 20mm star, it still wouldn't fit right. If the LED and small heatsink fit in-between the open space of the black holder of the EOS (like the user had in the link) then it would have fit perfectly.


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## CyberCT (Jan 19, 2012)

robostudent5000 said:


> did you cut out the centering bracket in the middle of the optic holder? the raised XPG won't fit unless you basically turn the optic holder into a hollow tube.
> 
> centering the LED manually can be a tough task. even a fraction of a mm can make a big difference in the beam so it's not uncommon to end up with a few rings when doing things manually. you probably did a good job if you have that one layer of tape on there and are happy with the results.
> 
> a Eos should run for a tick over 3 hours on high on Eneloops.



I clocked 3 hours 23 minutes before high and medium were nearly indistinguishable. No I did not cut out the plastic center bracket but I probably should have thought of that haha.


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## robostudent5000 (Jan 19, 2012)

how did you get everything to fit if the centering bracket is still on there? there's only about 2mm of space between an installed optic holder and the round plastic plug on the circuit board side of the battery holder. the 16mm star is probably 1.5mm thick and the Lux I star is almost 2mm thick. withe centering bracket still on there, there shouldn't be enough room for the optic holder to install properly or for the battery holder to install into the body all the way. did you maybe grind down the round plastic support plug on the battery holder to get the stars to fit?

if the epoxy hasn't dried to full strength yet, i would redo the mod. with the centering bracket intact, the XPG is 1.5mm too far away from the optic. not only is the optic not focused properly, it's also not capturing all the light from the XPG. you're probably losing 10-20% of the XPG's output.



CyberCT said:


> I clocked 3 hours 23 minutes before high and medium were nearly indistinguishable. No I did not cut out the plastic center bracket but I probably should have thought of that haha.


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## CyberCT (Jan 19, 2012)

robostudent5000 said:


> how did you get everything to fit if the centering bracket is still on there? there's only about 2mm of space between an installed optic holder and the round plastic plug on the circuit board side of the battery holder. the 16mm star is probably 1.5mm thick and the Lux I star is almost 2mm thick. withe centering bracket still on there, there shouldn't be enough room for the optic holder to install properly or for the battery holder to install into the body all the way. did you maybe grind down the round plastic support plug on the battery holder to get the stars to fit?
> 
> if the epoxy hasn't dried to full strength yet, i would redo the mod. with the centering bracket intact, the XPG is 1.5mm too far away from the optic. not only is the optic not focused properly, it's also not capturing all the light from the XPG. you're probably losing 10-20% of the XPG's output.



The epoxy is already dry unfortunately. I will see what I can do though as I'm sure I'll be able to get it all centered after playing with it a little and figuring it out.


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## robostudent5000 (Jan 19, 2012)

CyberCT said:


> The epoxy is already dry unfortunately. I will see what I can do though as I'm sure I'll be able to get it all centered after playing with it a little and figuring it out.



it depends on the epoxy you used and how much of it you used, but with most stuff you should be able to cut and pry it apart with a razor blade. 

to get the best possible result, the LED must be set closer to the optic. if you get it right, the LED will sit almost complete inside the round hole at the center of the optic and be encapsulated by it. 

best of luck.


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## CyberCT (Jan 19, 2012)

Success! When I first epoxied the XPG onto the stock filed down star, I got it pretty centered so all I did now was once I did a test fit, I used my thermal epoxy to glue the back of the star to the grey plastic circle behind it (which is supposed to support the stock star I guess?). I cut the center out of the black plastic holder leaving just bits of each end which fit snug up against the edges of the new 16mm star epoxied to the 20mm star. I used something as a weight to make sure pressure was put on the lens, black plastic holder, and LED onto the assembly. Took it off and the beam is better. I still put plastic tape on top to diffuse the beam. Perfect.

I did a test of my Fenix LD20 on hight mode with its Fenix diffuser on (the flat one that flips, not the cone one). And I think the output is a little better on the highest mode of the EOS than the cool white XPG-R5 LD20 on "high" mode. "Turbo" mode of the LD20 is better output than the EOS obviously. But overall I'm pleased with the neutral white color, getting sick of the drab blue / green output of my other lights on the lower modes. I'm going to buy LSD AAA Imedions which have about 14% more capacity than Eneloops. I already have and tested the AA Imedions and they are better IMO than the eneloops.


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## CyberCT (Jan 21, 2012)

I took my headlamp and went hiking for about an hour today in the snow. I also took my Fenix TK35 with me. I honestly feel the neutral XPG in my headlamp is a tad too warm in color temp. The TK35's cool white XML is a tad more pleasing on turbo mode (pure white), but on medium (which is about equivelant to the output of my modded headlamp?) the TK35 is a little too blue. So I guess it's not a very fair comparison but I kinda would like a color a little more neutral, between both lights. Maybe the XPG is not driven hard enough to get a little more "white" which is what the XML exibited? When I got home I took the tape off my headlamp and the color tint changed ever so slightly for the better, but still not enough. Again, maybe the LED isn't being driven hard enough. Walking in the snow I found the flood to be excellent. I don't really need throw I like flood for walking and seeing the path in front of me and to the sides. I don't need to turn my head just my eyes because the flood was decent at illuminating everything right in front of me.

I need to look into headlamps now. I think headlamps are great when hiking, and this is my first time finding out. If I can find a headlamp that is maybe twice the output at least, but still neutral (and I'll bet the same LED would turn a tad more white when driven harder) and floody, it would suit my needs. Is there maybe an easily moddable PrincetonTec headlamp that's double the output but still very easy to mod?

UPDATE: I actually am quite pleased with the stock optics (with my tape mod removed). The flood is still there, but now with more throw and I think a little more output. I really like this light. I highly recommend this mod to anyone who wants to try a basic mod.


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