Well, I took a different route for V2. I’ve been watching Rufusbduck build his fabulous coppery inventions by stacking sheet copper and soldering the pieces together. Which made me think about this 1” wide 1/4” thick bus bar I’ve got. So, being the proud new owner of a set of digital calipers, I sat down and took measurements, wrote notes, figured out just exactly what it’d take to fit everything I needed into the Mini C8. And found that the actual heat sink by necessity would be no more than a 1/4” thick. Just not room for much else, with given dimensions of the reflector, the driver, the led board and where it had to go.
So I took the copper bar out to the shed where the drill press is, hunted my one and only bi-metal hole saw and proceeded to cut a slug out of the copper, sans the centering drill bit so there’d be no center hole. Sometimes ya just get lucky! Come to find out, the slug I cut fit nicely into the Mini C8 with minimal to no work at all! So, with this new concept of “easy” in mind, I drilled 2 holes for the lead wires with my cordless drill (miraculously got them straight and they came out just where they needed to) and instead of overcomplicating things with a recessed cup for the driver, I merely used Arctic Alumina to glue it to the copper pill…after re-flowing a Noctigon directly to the pill. Glad I chose to reflow, as the already mounted XP-G2 R5 2B (same as the V1) had quite a bit of flux and solder come out from under it when everything went liquid! (There, obviously, had been too much solder under the emitter…it was not re-flowed properly to begin with)
So with everything looking good to go, and taking test measurements this time of the driver (it pushed my test XM-L on Al star at 2.89A, looking good!) I then glued the driver to the copper pill, everything is a tight fit here, so a little light sanding on the driver board to ensure fitment.
And with everything assembled, wires connected, loose and working as a complete light engine, it tested out at 2.6A on my DMM. The difference maybe between the XM-L in my test vs the XP-G2 having a different Vf, and possibly some battery loss…remember, this is an IMR10440 so capacity is only 350mAh!
With the light fully assembled, 18mm McGizmo reflector glued to the Noctigon for centering and assembly, I’m seeing 518 OTF lumens at start-up on a fresh Efest IMR10440, 459 OTF lumens at 30 seconds. It’s pulling 2.49A from the tail. And acting very much like a big light, at 89mm long with a 26mm head.
Ya just gotta love it when they practically fall together! I did some relief on the battery tube to prevent the very thick end from shorting the driver, other than that it was a pretty easy build, with the 2 holes through the 1/4” copper being the most difficult to pull off.
Room was totally dark, I used my chopped AA MiniMag Triple in ultra low mode directed at the Mini C8 to illuminate it for the picture.