Sigma PowerLED MCE mod


Newly Enlightened
Oct 9, 2008

I've been lurking around these parts for a while, picking up the info and courage needed for my own projects. Here's something in the spirit of giving back. (Haven't tried posting images before, hope it works!)

Upgraded my two 1st gen Sigma Sport PowerLEDs with Cree MC-E LEDs and TaskLED maxFlex2 drivers, running each MC-E in series at 700 mA from a 6V NiHm. Optics are 35 mm Ledils from Cutter. The lights run completely cool in outside temps around zero Celcius: overheating may be an issue in hotter climes.

I love the form factor of this light but was initially very dissapointed with its (lack of) brightness. Judging from the beamshots, I may have some more work to do in adjusting the optics for better throw. But right now, with all this extra luminousity, I simply can't be bothered.

IMPORTANT construction note after the fact: to my eternal shame, and despite carefully reading the product sheets, I apparently made a grave error in pouring Artic Silver epoxy over the driver. I have now learned that Artic Alumina would have been the right choice. Don't repeat my mistake!


All the parts layed out. Hadn't decided on the application when I ordered the MC-Es so opted for the individually addressable star - and had to wire it in series by hand. Not a big deal but getting a pre-wired star would have been better. Doubled up the flimsy, original o-ring to better hold the optic in place, and hopefully improve water resitance a bit.


The modified driver assembly with the new momentary switch, the maxFlex2 driver with status LED and heat conducting tab - all epoxied together in a neat little package. This was a lot of work.


I filed off the tabs that held the original driver in place and glued on some small pieces of plastic to create a nice, flat surface to epoxy the driver onto. (Also barely noticable through the transparent goo is the first layer of Artic Silver - remember to use Alumina - heat conducting epoxy.)


Cut and glued on some of the original material used for preventing the red status LED from being drowned out by the main light. (This didn't work so well, as there's simply too much light coming in from the main LED). Also filled a gap in the material along the inside edge with Artic Silver to increase heat transfer to the main housing (tube). Judging from how quickly the outside of the housing heats up in stationary tests, the resulting thermal conductivity is pretty good.


The driver assembly back in place inside the housing, secured with two globs of epoxy to prevent it from rattling loose on the trails. At the bottom of the assembly, note the plastic wedge which locks it in place inside the tube. The key to taking the original light apart without destroying it was to start by carefully pulling this wedge out.


The finished item. No notable difference - until you switch it on!


The backside with the downside: all that brightness comes at a price in amps. I'll be looking into a more powerful battery next...


Ledil Eva-SS beamshot app. 1.2m from wall


Ledil Eva-M or EVA-W (can't tell them apart) beamshot app. 1.2m from wall


For comparison Ultrafire R1 single rebel, single CR123A beamshot (wall)


Trail beamshot: Ledil Eva-M or EVA-W (still can't tell them apart). Too much diffusion going on here.


Trail beamshot: Ledil EVA-SS (handlebar mount). More focused light, but still best for near-field and periferal vision.


Trail beamshot: Both MC-E'd Sigma lamps on full. Bright as day, at least close up.


Trail beamshot: Two Sigma MC-E PowerLEDs (on handlebar) plus Romisen RC-T6 (on helmet). Note how the Romisen adds both throw and spill.


For comparison Ultrafire R1 single Rebel, single CR123A beamshot (trail)


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Newly Enlightened
Jan 2, 2007
Lleida - Spain
Hi, don't it see the pics!!!!!!!!!!

Could you put more pics with the details of the change of the led and the driver and how you take out the original driver, please?


Greetings - Saludos



Newly Enlightened
Oct 9, 2008