the sixfink's first torch mod

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the sixfink's first torch mod

Despite some grinding and beadblasting here and there, swapping out commercialy available P60 dropins and the ubiquitous dreaming and planning, I have finally come around to mod my first flashlight. It's rather crude, by any definition, but I finally "updated" a ten years old light into something useful.

Things all started a few weeks ago when I looked at the torches I got from my best buddy about a decade ago. Back then we were both still busy getting our degrees, me in architecture and him in electronics engineering. One class at polytechnic had this flashlight as one of their projects, and they did a very small batch, some sort of a pilot run that, of course, was never meant to be available commercially.

Back around Y2K, affordable LED flashlights were mostly the type that incorporated that cluster of common 5mm emitters mounted on a board. This one already had one of the larger, modern SMD emitters, regulated by a simple resistor. I remember it as mighty bright back then, but compared to a minim@g terralux conversion, it's output is merely pathetic. So, I tried to be creative.

Here, two of those lights can be seen. The emitter is soldered to a piece of board which in turn is screwed to an aluminum (aluminium for you in the UK) carrier. It pretty much resembles some sort of a "dropin", unfortunately one that would neither actually drop right in, nor conform to any industrial standards except for the thread pitch.


Looking at the SolarForce XM-L T6 I had just pulled for no real reason from my Surefire 6P (shelf queen, obviously), I somehow thought it'd be a nice idea to adapt the T6 pill to the threaded carrier. No pics of that build, however, but I found it quite tough to machine that taper. I messed up somehow, as the pill wouldn't completely seat, no matter how often I hand-lapped the two parts. Enter the bench vise, two spacers improvised from hex sockets, much caution, a very tiny blob of silver arctic epoxy and a little larger blob of blatantly common JB-weld on the outside. The finished thing looks like this:

While the pill behaved well and quite promising behind 3xAAA batteries @ 4.5 volts, drawing 1000mA for about half an hour before it starts to dim, it sat too low in the light for the reflector. Out came the scrollsaw, and after ten minutes I had finished cutting a spacer ring from 2mm aluminum sheet, with a wall thickness of 0.5mm. I was cursing and swearing a lot while doing this:

I had to sand it down about 0,2mm in height, by my preferred method - "try and error". That brought the emitter up to the desired position. Hotspot, spill, corona - everthing was fine now, with no pesky artifacts.

The switch, a generic KAN-28, was left alone. It merely received a little cosmetic makeover with a GITD rubber boot. Of course, new silicone O-rings all around (standard, no GITD, which wouldn't make any sense at all) and a dab of Nyogel 760G were mandatory.


Now, this wouldn't be BLF if I couldn't provide at least some sort of beamshots or such. Well, I was in a rush, so the ceiling was better than nothing, and a LED Lenser P7 served for comparison. Home-butchered T6 3xAAA sixfink hack on the left, P7 on high mode on the right. I really like the results.

It made a great gift for my friend tonight. He was amazed by this rather simple hackjob, and very happy.

Edited by: sixfink on 04/21/2011 - 21:24
Match's picture
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Well Done, Sixfink! Looks like it turned out great.  I like the ingenuity displayed with the jb weld and the aluminum spacer ring.  I understand completely how big of a pain it can be to work and fit those things sometimes.

Again, great mod!

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Don wrote:

"But as I said long ago, you are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion

Budgeteer's picture
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Nicely done Sixfink! I like how you modded the pill! Smile

kragmutt wrote:

They're gonna send you a green redcat with a black LED.

Last seen: 3 years 7 months ago
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Even more delightful, the pill doesn't generate much heat at all. I went through three sets of alkalines, and it only gets slightly warmer than ambient temperature for about half an hour.

I was anticipating some difficulties in the thermal department when I first threw it together. Rather unexpectedly, it runs FAR cooler than it did in the SureFire 6P, even with a set of somewhat drained CR123A (together 4,8V under load). Dual lithium primaries turn the single-mode solarforce T6 pill into a real handwarmer instantly.

This real-world experience also shows a slight drop in current means a big difference in heat generation on the T6, while output doesn't suffer that much. I recall Don and Budgeteer mentioning that anything above 2.5A won't really add much to the brightness of an XM-L T6 (or was that a U2, actually?Embarassed), but generate tons of heat instead.

If I was really crazy, I'd try to measure actual lumens output, but then again, numbers alone won't light up the darkness. To me, it was merely a question of "bright enough to be satisfying". It is, and the slightly warmer tint is somewhat easier on the eyes as well, compared to the XR-E (unknown bin, maybe R2 or Q5?) of the P7. The comparison shot doesn't really show that, though.