Installing a STAR in the Aleph Light Engine

PhotonFanatic

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Dec 17, 2003
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Not sure why I take these projects on--it seems that something that should really be simple, such as replacing an emitter, can turn into a multi-day modding project. :rolleyes:

The owner of the Aleph LE, a NG750, just wanted the emitter upgraded from a Lux III to a Seoul P4. Only problem was that the emitter was epoxied in place. OK, no big deal, just freeze it and knock it off. Not quite--I didn't realize that there was a copper disk under the emitter--and that disk was what separated from the anodized heatsink.

No way did I want to try to reinstall an emitter with a copper disk under it, so I thought, why not just turn down a star and install that instead? Seemed simple enough.

Here's the LE after it was gutted on top:

GuttedLE.jpg


Turning down the star to 15.10mm, the diameter of the LE opening, wasn't as easy as I thought it would be. My first jig designed to hold the star wasn't good enough--not enough grip on the star to be able to turn down the diameter. Onto Jig #2--this time I payed very close attention to the tolerances and I chose to make it out of Ti, too.

That worked fine, not only allowing me to turn down the star, but to also install the holes for the leads--which perfectly matched the holes in the LE top.

Here is the result, before the final tweaking and soldering. I plan to use thermal compound, not epoxy to hold the star in place. The edges of the star will be coated with nail polish to provide some isolation, although it shouldn't be needed. But I did notice that there were a couple of bare AL spots showing, so better safe than sorry.

TrimmedSTARinPlace.jpg


I think this mod will actually increase the thermal transfer from the LED to the body of the light--there is no a lot more surface area in contact with the LE than there was with just the copper disk in place.
 
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The emitter PCB and copper disk were at .79mm from the top of the anodized heatsink, so that's what I made the thickness of the star's MCPCB to be.

Might have been better to have had the head of the light to go with the LE, but matching the original height should be pretty safe, no?
 
I am not sure whether the emitter is the same height in the Seoul- I think it needs to be shimmed up higher than a Lux III. Trial with the reflector will give the truth....good luck.
 
Just to put the record straight, it was an SSC-P4 L.E (not a luxeon L.E)
that I sent to PhotonFanatic originally.

The copper shim that was on there was to put the original SSC-P4 to
the correct height.

I asked PhotonFanatic to replace the original SSC-P4 with a U2-bin
SSC-P4 at the same time as he replaced the missing solder blob
that the anode of the battery makes contact with.
 
Hi Fred,

Any pics of the Jig you made?

I usually enjoy those types of pics as much as the mod pics.

Thanks,
Michael
 
Michael,

Well, actually one needs two jigs to do the job. The first one:

Jig1.jpg


That fits the six holes around the edge of star MCPCB. I install the star in that and then turn the star down to less than 20mm in diameter, which is the maximum size collet for my lathe.

That rounded star is then drilled with three holes to accept the prongs of the second jig:

Jig2-A.jpg

Jig2-B.jpg


The second jig is made of Titanium--it has little landing zones on the prongs where the bottom of the rounded star rests. When the jig and the rounded star are placed in a collet in the lathe, the collet tightens down on the prongs, holding the MCPCB strongly enough so that I can then turn it down even more--in this case to 15.10mm in diameter.

The final op on the lathe would be to drill the holes for the leads--matching the 10mm spacing in the anodized eCan.

Jig2-CWithLEDinPlace.jpg


Here's a top down view with the jig in place:

Jig2-DTopView.jpg
 
Just to put the record straight, it was an SSC-P4 L.E (not a luxeon L.E)
that I sent to PhotonFanatic originally.

The copper shim that was on there was to put the original SSC-P4 to
the correct height.

I asked PhotonFanatic to replace the original SSC-P4 with a U2-bin
SSC-P4 at the same time as he replaced the missing solder blob
that the anode of the battery makes contact with.

Ahh now I see. Sorry I should have kept my mouth shut. Hope all goes well (always does with Freddy in charge)
 
Ahh now I see. Sorry I should have kept my mouth shut. Hope all goes well (always does with Freddy in charge)

Not at all. Its only natural to ask questions and show an interest in our
collective hobby. They were good questions too. :thumbsup:
 
Thanks for the pics Fred,thats some really fine work you've done there!

I always enjoy seeing the mechnical/problem solving side of things.

Thanks Again,
Michael
 
Well my Star U2-bin SSC-P4 Aleph-LE arrived today and its a very
good fit and impressively white and bright.

I am also delighted to have such a unique L.E and appreciate all the
work that's gone into it. Thanks Fred. :twothumbs
 
Daniel,

Good to hear that it fit so well. It can be hard to get everything right when one doesn't have all the components on hand.

While tougher that I had expected, it was a rewarding learning experience. :devil:
 
I have an original Aleph with a Lux III. Is there anyone who would upgrade it to a modern high output Cree or Seoul for me?

I bought a Fenix TK10 and that light on low is equal to the Aleph on high:mecry:

TIA

P.S. I also have a few headlamps that need updating.
 
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