PT EOS Seoul & Reflector Mod Writeup

[cave dave]

The sensor - the one that can break - its a thermal sensor for overheating protection right? Before I go ahead and break the thing (90% chance ).

Correct and many people have broken it and can't tell the difference in function.

I turn the light on and run it on high for 15 min or so to get the star board nice and hot, before I give a tug on it. The theory being this softens the epoxy holding onto the sensor. Haven't broken one yet.

[Dan_GSR]

i just finished mine today
very happy with the results

i used a USVOH Seoul P4 star
and a McR-18 Seoul

[Ducaticorse]

*Oops, my apologies realized the question I'd asked has already been answered!*

[Ducaticorse]

I just finished modding (my first mod of any kind!) two EOS headlamps with a couple nice USVOH P4 stars from Fred/PhotonFanatic. They both turned out super! I'm pleased with the improvements, no question. Fred's emitters have a much more natural tint than the stock Luxeon, probably worth the cost of the mod alone.

I personally find that the stock optic gives a very nice, usable beam with the Seoul emitter. I did install a smooth 17mm Khatod reflector in one just for laughs, and it does force more light forward, with a bit hotter center spot and a more defined outer "edge" to the beam. I left the smooth reflector in the one light for now, it looks good.

In the other light, I wanted something with a smoother, "floodier" pattern. As I mentioned above, the SSC does provide a pretty smooth beam with the stock optic. I added a bit of diffuser material (waynejitsu's Fellowes WrightRIGHT) to the lens on this light and it provides exactly what I was after - good center brightness, but a super smooth decay of light as you go outward in the pattern. I found that using a penny as a "template" to cut the diffuser material provided an almost perfect size for the EOS's lens.

Thanks for the great thread and the info on the mod. These lights were purchased for my wife and daughter to use in camping and outdoor activities, but the super-smooth version will likely see use from me in around-the-house duty.

[Mayqswet]

I've been reading for a few days, with interest, about the EOS mods. Where would be a good place to purchase one already done?

Thanks.

[gunga]

PM sent.

[gunga]

For fun, just thought I'd post some more pix of the battery pack mod, lots of work, but it turned out well in the end.

Hope you guys enjoy!

[greenLED]

Hubba-hubba-hubba!!

Need links to more info, parts list, etc. gunga!

[gunga]

Okay, I'll get to it at some point...

Would you rather I start a new thread or just dump it all here?

Gonna be a while before I can get all my info togther tho.

[greenLED]

Awesome!

(I'd personally dump it all here so everything related to modding the Eos is in a single thread.)

Looks really interesting, especially that grommet, and the cable, and the battery, and...

[sfCyclotourist]

I've been reading for a few days, with interest, about the EOS mods. Where would be a good place to purchase one already done?

Thanks.

Yeah, me too. I'd be interested in one with the stock optic (going to use it as a bike-helmet light). Thanks!

[gunga]

He he.

I'd offer, but I no longer have a source of reasonably priced stock EOSes to mod.

It's pricey up here!

[burningrome]

Thanks all for this very useful post - came a bit late to the game. Does anyone have a cache or saved page of the original post, as all the photos seem to have disappeared, and I want to try this mod.

thanx

[cave dave]

You don't really need pictures. Once you get it open you will see what you need to do. If this isn't the case maybe modding isn't your thing. Read the entire thread. The 1st post isn't the only way to do it.

-Unsolder the red and black wire.
-Replace Lux star with SSC P4 star.
-Solder Wires back on. (polarity is marked on board)

[mcmc]

I plan to make a few stock optic (really like it) SSC modded EOS'es...pm me if interested =)

[burningrome]

Thanks, Cavedave.

[TMorita]

For fun, just thought I'd post some more pix of the battery pack mod, lots of work, but it turned out well in the end.
...

Where did you get the grommet/strain relief?

Toshi

[gunga]

grommits were rubber grommits from local electronics shop (local brand, mode electronics I think, pretty generic). Used a zip tie on the wire inside as strain relief.

[xcandrew]

Now that I modified a second Eos for my girlfriend, and I thought that I would add a beamshot comparison for the two reflector/color bin combinations that I have.

On the left is the new Eos with the Khatod 17 mm smooth surface reflector and USVOH bin P4, and on the right is my old Eos with McR-18S reflector (orange peel) and U-bin P4 from Deal Extreme (WO color bin? bin not marked on star).



Both reflectors are said to be optimized for the Seoul P4. There are some faint rings in the Khatod beam, while the McR-18S beam is perfectly smooth, but it should be better considering the price difference ($4 for Khatod vs. $18 for McGizmo). A smaller consideration is that the McR-18S also looks better because it fills the lens perfectly, while you can see the smaller diameter, somewhat rough rim of the reflector in the lens with the Khatod. Functionally, both are excellent beams for my uses - mainly running and cross country skiing, and also walking/hiking, biking, night orienteering.

I briefly tried the stock optic with the USVOH in the new Eos, and it made for a wider and more useful beam than the same optic with the Luxeon, but (Khatod) reflector somehow seemed to improve not just the spill, but the overall output noticeably.

Here is a comparison of the the two setups in an outdoor scene. Daylight white balance and exposure was identical at ISO 800, 3 seconds, and F3.25.

McR-18S and U-bin from Deal Extreme(DX)


Khatod 17mm smooth and USVOH


As you can see, the McR-18S/U-bin from DX combo is a lot brighter. I tried to position and aim the two setups the same, but the McR-18S/DX P4 might be aimed a bit more to the left to light up those closer trees better, while the Khatod/USVOH might light up the trees further back to the right of the trail a bit better. The difference in foreground brightness is substantial.

In normal use, the Khatod/USVOH combo is also noticeably dimmer. Voltage drops across the LED for my old (brighter) Eos are 3.15V, 2.90V, and 2.72V for high, medium, and low, respectively, while the voltage drops for the new Eos are 2.96V, 2.77V, and 2.64V. (I have imprecise current measurements for the new Eos/USVOH: about 300 mA high, 90-100 mA medium, 20-30 mA low.) Can anyone explain the differences in voltage drops? Circuitry differences between my old Eos (2004) vs. new Eos (2008), manufacturing variations, or is does it have to do with the Vf of the LED? I kind of remember Ktronik or may someone else concluding that the Eos was voltage, not current regulated, so maybe it's the circuitry.

I have other difference between the two Eoses. The old Eos with the McR-18S/DX P4 is running off of an external pack with 4 AA Eneloops (as detailed previously in this thread) in the beamshots, but the voltage drop across the LED is the same when running 3 internal AAAs. The old Eos also has a coppy penny heat sink. The NTC thermistor is reconnected in both Eoses, but at 15 degree F when the outdoor photos were taken, I don't think it matters.

I kind of see the advantage in color rendering that some people claim for more the more yellowish color, but the on snow and white walls, I notice that the hotspot of the USVOH Eos looks like urine (left side in the following photo), and I can't stop noticing the pee color. I admit that in most other situations it's not bad. I did buy an extra USVOH for the old Eos, but I don't think I'm going to put it in now.

[candlelight001]

Looking for someone to put a Seoul in my EOS, please PM me if interested or know who might be. Thx!

[Mark620]

I think the PhotonFanatic khatod non-stippled reflectors with a rubber band or double sided tape between them and the optic holder are the next best choice but have not tried this personally. I do have one laying around and when I pick up another EOS to mod(since there are STILL no Cree/seoul headlamps available (except the ZL which is all flood)) I will try this out and update the original thread..

As someone else posted here is the reflector mounted in the optics holder in this case using a rubber band as a spacer:

I have been using a O-ring on the front edge of the reflector to keep it from rattling and hold the reflector against the LED.

[tibim]

Pictures fixed =)

[Dougie Dukakis]

I did the mod myself recently to an EOS bike, but I have to say I'm quite disappointed. I hope you guys can help me troubleshooting:

I left the stock optic in, as I wanted to have as much throw as possible. But compared to a older cree dropin for my SF C2, (I think it's a Cree P4) it puts out less than half of the brightness. So far I've been running the EOS with new Duracell AAA Rechargeables as well as cheap alkalines from supermarked. I thought of running Lithium AAA primarys but I can't imagine they make such a big difference as I would hope for.

Can you guys give me any info, is it normal that the output is so bad compared to my dropin on the SF?

[cave dave]

yes, the EOS doesn't drive the LED very hard. Somwhere between 250mAH to 300 mAh. A P4 is rated to 1000mAh if well heatsinked. A P4 in a PT Apex is much brighter since it is run quite a bit harder.

[Dougie Dukakis]

Thanks for the info cave dave! Is there anyway to mod this to get it to 1000mAh?

[cave dave]

Thanks for the info cave dave! Is there anyway to mod this to get it to 1000mAh?

Not really, their is no external heatsink so you would likely fry the LED, and anway 3AAA's wouldn't drive it for long.

[Dougie Dukakis]

Not really, their is no external heatsink so you would likely fry the LED, and anway 3AAA's wouldn't drive it for long.

I wouldn't care about runtime, 1 hour would be alright with me but I do see the problem with the missing heatsink. Could I just solder in a ~600mAh driver board form DX or similar? If so, would you know where to connect it?

[Tidra]

GUNGA,...

very nice mod, I was thinking to do something like this, but use one 18650 or D Li-Ion instead of 3xAA NiMh

Li-Ion =~ 4.2V (4.15V)
3xAA NiMh=~ 4.35V (4.3V)

I think that diference is not too big,...

Cheers,
Iztok

[Dougie Dukakis]

Please someone tell me how to get rid of the old driver to run it with a higher mAh rating. Is there maybe just something to bypass, or do I need a new cicuit board?

I promise I post pics once I'm done and compare runtime!

[candlelight001]

Just did the basic mod, very cool! First of all, thanks to mcmc, mark628, and greenLED in particular for the encouragement and tips. I have 0 electronics and 0 soldering experience and found the mod quite doable. After going back and forth between the khatod reflector and the stock optic, I settled on the optic. I was surprised by how much the stippled reflector robbed the light of throw. With the stock optic I've got wider beam, smoother, but still got some throw. Awesome. What's next?