Bought one of those inexpensive MXDL 3W CR123A twisties from Kaidomain:
Also available from dealextreme:
Also picked up a number of star-mounted SSC P4 U-bins (Kai is no longer selling these, but you can get them at DX). I figured it was worth fooling around a little with these, and boy did this relatively easy mod produce fantastic results!
Some have called this light a P1 clone, but that's a little optimistic. Machining is rather rough, only a few threads on the body, plastic reflector and lens, etc. See disassembled pic below and Kai/DX website pics. Note that exterior anodizing is fairly even (though thin), and it's not a bad looking light. "Cheap but cute" is how I would sum it up its appearance.
Stock light output is quite poor, frankly. Angry blue with yellow corona, poorly focused (reflector is not well suited to cheap luxeon clone). Throw is no better than the infamous 1AA Elly (a moder's favourite), although overall output is ~50% higher (poor reflector means floodier beam). Runtime on a blue-wrapped AW protected RCR 750mAh was 41 mins to shut-down. Sorry no pics, I was in a hurry to get moding!
The head is easy to open - just unscrew using snap-ring or needle-nose pliers, no loctite here. You can remove the lens and plastic reflector, but there's no point - this mod doesn't require any modification of the reflector, and you are best leaving it alone for reasons that will become clearer soon.
As shown above, I desoldered the leads from the mini-disc with the lux clone emitter, and it comes right off. FYI, no thermal paste to be seen. First problem is how to get a SSC on there. Disc is only 15mm wide, so too small for a star swap. Others have tried a Cree mini-disc swap, with poor results (requires reflector mod).
My solution was to simply clip off the SSC emitter tabs from a replacement star. Didn't bother desoldering the emitter, since the tabs are too long for this mod anyway. Just trim them off and clean away the thermal paste from under the slug (lifts right off the Kai SSC stars). I then did NYLITE's slug isolation trick with arctic alumina thermal adhesive:
After leting the thin layer of epoxy cure for a few hours, I then placed the isolated emitter on the back end of the anodized mini-disc and fitted it back on the head assembly, as shown above (ignore the wires for now - they are actually on the wrong side in that image for the temporary mount - sorry!).
My plan is to use the old mini-disc as a base on which to mount the emitter, and for the time being, flipping it over works well. As you may have guessed, from this point on my mod will be very similar to EngrPaul's excellent tutorial on the LED lenser: http://candlepowerforums.com/vb/show...&postcount=116
First thing at this point is to verify the emitter does not have continuity with the aluminum base using a DMM. Next, apply a fresh dose of epoxy to the center of the upturned mini-disc, and mount the isolated emitter as close to the center as you can. Press down firmly to extrude most of the epoxy (you just want a thin layer under the emitter slug). Working quickly, screw the head assembly back into the head unit so that the emitter is right up into the base of the reflector, as shown below.
You'll note that it is a perfect fit with standard reflector. By screwing it together tightly, you are insuring a minimal amount of epoxy directly under the emitter. It will also be perfectly centered. Let sit overnight to cure fully.
After removing the head assembly the next day, you should see something that looks like my earlier picture. You will note that I seem to have a lot of epoxy around the base of the emitter. This is because I made sure to extrude as much as possible, leaving only a small layer underneath (hopefully ...).
Since the emitter sits higher than the old lux clone, the head assembly won't screw in as high into the head unit. This is not a major problem (still enough body threads to make contact), but it's good to file down mini-disc's "old" surface with the lux clone on it at some point. This will also help insure good thermal contact to the rest of the head when you do the final mount. Incidentally, the reason I chose to use the back-side of the mini-disc star with this mod is because I knew I'd make a hash of the other mini-disc surface with my dremel (which I did). But who cares, it's underneath everything important now.
Apply a little thermal paste (I use arctic silver) to the inside of the head assembly and place your mini-disc in position with two wires poking through where they should be to easily connect to the emitter. Pay attention to the polarity - the blue wire was (-) on my unit, so it's connected to the (-) terminal of the SSC. The notched limb on the emitter is the (-) terminal indicator. Don't get this backward! Unfortunately, I took the earlier picture above with the wires reversed (sorry about that) - in the final mount, the blue wire is soldered to the (-) terminal. Again, see EngrPaul's excellent threads for more info.
Simply solder the two wires to the emitter, and reassemble everything. How did it turn out? Here's a few exposures for you for the beam profile:
Note that in real life, I don't see a ring around the corona - only the camera is picking that up.
Output is amazing: according to my light meter, throw has doubled, and overall output has tripled!!! Runtime is unchanged at 41mins on the AW protected. Tint is excellent, very white (maybe slightly cool).
To put this in perspective, here it is up against the P1D CE. Both shots were taken with exact same manual camera settings - F4.0 and shutter 1/8.
Energizer e2 lithium CR123A
MXDL-SSC on left, P1DCE on medium (primary) on right
High-current AW protected RCR123A, 750mAh (black label)
MXDL-SSC on left, P1DCE on high on right
Note that the P1DCE runs direct drive on these batteries, until it decays to a point where the regulation kicks in. You are looking at initial brightness.
Conclusion: WOW! What can I say - on primaries, this light is almost as bright as the P1DCE on medium (primary). On Lithium-ion, overall brightness is ~90% that of the P1DCE on max.
By any stretch of the imagination, this mod was a fantastic success. Well worth the $14 for the light and SSC emitter. Enjoy!