Few weeks ago I've received yet another flashlight delivery from FastTech.com. This time it was a budget SK68 clone sold for under US$6, branded as "Uinfire B68". My first zooming flashlight after some 30 odd years! Back in the happy days of former Yugoslavia, my favourite flashlight was old skool tin-bodied "Varta" 2*C reflector zoomie with No. 222 incan bulb...
Skimpy packaging quickly gave way, revealing one black, mean, Klingon-ish looking but surprisingly small 1*AA/14500 light sabre:
To be honest, holding my B68 for the first time felt like holding a brick: this thing surely wasn't designed to meet any ergonomic standards! "Tactical" crenelated bezel and aggressive cooling fins (latter being positioned in the wrong area, anywayz) sported some rather sharp edges left from machining. A pad of steel wool came in handy to sort out the imperfections, to make the flashlight more pocket- and finger-friendly and of course to bring that much desired worn-out anodizing look;) Black HA coating proved to be quite tough to remove, so I was forced to use very coarse grade of steel wool, commonly used for kitchen pan scouring. If you're doing this, be sure to protect the plastic lens from scratches (with masking tape or similar).
Only later I've discovered that shape of B68 perfectly supports the type of hold intended for the purpose of striking, but this type of usage won't be elaborated any further. After all, this small flashlight shares a genealogical line with the famous Nitecore Extreme...
Only later I've discovered that shape of B68 perfectly supports the type of hold intended for the purpose of striking, but this type of usage won't be elaborated any further. After all, this small flashlight shares a genealogical line with the famous Nitecore Extreme...
Company logo and model name, laser-etched.
Out of sheer boredom I've unscrewed the bezel ring and left it to sit for some 10 minutes in a plastic cup with a household-grade drain unclogger (liquid alkali gel), so anodizing went away completely and, after some rinsing, bare satin finish aluminum surface saw the bright daylight. Unfortunately I haven't been able to remove the lens before de-anodization, but this glued-in PMMA aspheric withstood the process heroically and without any visible surface marks. (If you're messing with drain cleaner, protect your skin and eyes properly).
My sample of B68 has a solid pill, i.e. emitter board is fully backed by a wall of solid aluminum. This fact translates to considerable modding potential, since you can apply thermal paste under the original emitter board and tighten it onto the pill wall with screws, or go for a custom copper board to reflow the LED onto. After managing to remove the original plastic retaining ring intact, I've swapped the original 1-mode driver for 5-mode FT replacement (read further for details) and applied electrically non-conductive Chillaramic thermal paste under the board and on the outside threads of the pill, while keeping the stock emitter/board combo. One shim was placed under the driver to ensure firm contact with negative pole (battery tube). After this mod, my B68 is getting warm quicker than stock version and sustained use even in High mode shouldn't be a problem any more.
When fully defocused, B68 produces a "full moon" (hotspot-less, blobby) flood. Or, when fully focused, it projects a very tight, dense and crisp square-shaped hotspot - actually a projection of a square LED die. Between these two extremes are oft-forgotten but quite useful transitional stages. B68's beam quality is good, with minor ring-shaped artifacts (outside the beam itself, which are visible only on the white wall at short distance). Aspheric lens is clear acrylic glued to the bezel ring, manufactured without scratches or other defects visible to naked eye. LED tint is cool white, with max. OTF luminous flux somewhere around 120lm, maybe a bit more. On my sample, focusing action was smooth right out of the box. Instead of elastic steel C-ring common to "original" Sipik SK68 and some of the clones, my Uinfire employs one slightly lubricated rubber O-ring to keep the desired amount of friction and to smoothen the zooming movement. This solution works OK. With some practice, I've managed to repeatedly perform full focusing and de-focusing in an overhand (a.k.a. police/tactical) grip with ease, using one hand only.
Slightly annoying thing I've noticed is a substantial free play between zooming head and a part of flashlight body where the pill is located, which allows the head to wobble a bit from side to side. In reality this doesn't seem to affect the beam quality at all. In the future I might place a layer of plastic film or a small sheet of beercan tin there to elliminate wobbling, but for now I'm comfortable with it as it is. Sliding mechanism is very straightforward but it requires a bit of cleaning and a very small amount of silicone grease from time to time, to maintain soft and smooth zooming. From my experience with this SK68 clone, too much grease almost completely elliminates the friction and this can be annoying, as head starts to slide by itself due to its weight.
My sample of B68 has a solid pill, i.e. emitter board is fully backed by a wall of solid aluminum. This fact translates to considerable modding potential, since you can apply thermal paste under the original emitter board and tighten it onto the pill wall with screws, or go for a custom copper board to reflow the LED onto. After managing to remove the original plastic retaining ring intact, I've swapped the original 1-mode driver for 5-mode FT replacement (read further for details) and applied electrically non-conductive Chillaramic thermal paste under the board and on the outside threads of the pill, while keeping the stock emitter/board combo. One shim was placed under the driver to ensure firm contact with negative pole (battery tube). After this mod, my B68 is getting warm quicker than stock version and sustained use even in High mode shouldn't be a problem any more.
When fully defocused, B68 produces a "full moon" (hotspot-less, blobby) flood. Or, when fully focused, it projects a very tight, dense and crisp square-shaped hotspot - actually a projection of a square LED die. Between these two extremes are oft-forgotten but quite useful transitional stages. B68's beam quality is good, with minor ring-shaped artifacts (outside the beam itself, which are visible only on the white wall at short distance). Aspheric lens is clear acrylic glued to the bezel ring, manufactured without scratches or other defects visible to naked eye. LED tint is cool white, with max. OTF luminous flux somewhere around 120lm, maybe a bit more. On my sample, focusing action was smooth right out of the box. Instead of elastic steel C-ring common to "original" Sipik SK68 and some of the clones, my Uinfire employs one slightly lubricated rubber O-ring to keep the desired amount of friction and to smoothen the zooming movement. This solution works OK. With some practice, I've managed to repeatedly perform full focusing and de-focusing in an overhand (a.k.a. police/tactical) grip with ease, using one hand only.
Slightly annoying thing I've noticed is a substantial free play between zooming head and a part of flashlight body where the pill is located, which allows the head to wobble a bit from side to side. In reality this doesn't seem to affect the beam quality at all. In the future I might place a layer of plastic film or a small sheet of beercan tin there to elliminate wobbling, but for now I'm comfortable with it as it is. Sliding mechanism is very straightforward but it requires a bit of cleaning and a very small amount of silicone grease from time to time, to maintain soft and smooth zooming. From my experience with this SK68 clone, too much grease almost completely elliminates the friction and this can be annoying, as head starts to slide by itself due to its weight.
This little bugger is bright even with a stock single-mode driver and on a diet of freshly charged white Eneloops. These NiMH rechargeables keep their charge long, have low voltage sag and are notorious for their ability to
deliver and withstand enormous drain currents, so I prefer them over any alkaline battery available. I don't have any 14500 Li-ions at the moment, so I haven't tried them. My 5-mode FT replacement driver doesn't support 4.2V, although stock driver supposedly handles this voltage easily, with stunning results and a bit more excess heat...
Tailcap current measured with original single-mode driver and one freshly charged Eneloop battery reads exactly 1.5 Amps. After some thermal improvement and a driver swap (FT 0.9-3.6V, 550mA, 5-mode driver installed) tailcap current went up to devastating 2.15 Amps in High mode. I'm not sure how this improvement exactly relates to OTE lumens, but a beam produced by a tiny XP-E emitter looks a bit brighter than before. It should be mentioned that there's also a stock 3-mode (Lo-Hi-Strobe or similar) B68 version available on FastTech.com.
Both stock and replacement driver failed to provide a stable light output when NiMH batteries were used, so expect the brightness to gradually decrease with elapsed time when you use this battery chemistry, and always provide a fresh battery for maximum possible output. As I have a serious doubt that alkaline batteries can deliver 2+ Amps (at least for any sustained period of time), I'm planning to stick to Eneloops for the time being, and perhaps sometime reinstall the stock driver and go the Li-ion path... Runtimes in High mode are modest: I reckon no more than 60 minutes on 2000mAh battery, estimated.
New driver allowed for lower consumption in Med and Low modes (around 5 hours in Low) so it significantly contributed to EDCability of this flashlight. Besides all other brand name single-cell flashlights that I currently own, I've never imagined carrying a cheap Chinese zoomie as my regular every day carry flashlight, but after a week of extensive use I've realized that B68 isn't a cheap toy, but a worthy and versatile companion which effortlessly covered most of my daily lighting needs.
My subjective judgement is that stock B68 usefulness ends with a 100-meter mark in an urban environment with moderate light pollution, and (obviously) more in a complete darkness. Therefore I'm planning to take it with me on my next visit to the countryside and enjoy playing with it in dark night sky and scenery. Fully focused beam (although with reduced lumen output due to inevitable light losses) is tight and dense enough to produce a very pleasing "light sabre" effect even in mildly foggy air - one feature of this flashlight which is very desirable for the inner child in all of us, he he;)
Magnified Cree XP-E emitter, viewed through the aspheric lens.
Tailcap current measured with original single-mode driver and one freshly charged Eneloop battery reads exactly 1.5 Amps. After some thermal improvement and a driver swap (FT 0.9-3.6V, 550mA, 5-mode driver installed) tailcap current went up to devastating 2.15 Amps in High mode. I'm not sure how this improvement exactly relates to OTE lumens, but a beam produced by a tiny XP-E emitter looks a bit brighter than before. It should be mentioned that there's also a stock 3-mode (Lo-Hi-Strobe or similar) B68 version available on FastTech.com.
Both stock and replacement driver failed to provide a stable light output when NiMH batteries were used, so expect the brightness to gradually decrease with elapsed time when you use this battery chemistry, and always provide a fresh battery for maximum possible output. As I have a serious doubt that alkaline batteries can deliver 2+ Amps (at least for any sustained period of time), I'm planning to stick to Eneloops for the time being, and perhaps sometime reinstall the stock driver and go the Li-ion path... Runtimes in High mode are modest: I reckon no more than 60 minutes on 2000mAh battery, estimated.
New driver allowed for lower consumption in Med and Low modes (around 5 hours in Low) so it significantly contributed to EDCability of this flashlight. Besides all other brand name single-cell flashlights that I currently own, I've never imagined carrying a cheap Chinese zoomie as my regular every day carry flashlight, but after a week of extensive use I've realized that B68 isn't a cheap toy, but a worthy and versatile companion which effortlessly covered most of my daily lighting needs.
B68 with bezel ring and lens removed ("mule" config): Emitter board is retained by a press-fit plastic ring (white) and thin stainless steel disc, with plastic insulation shim placed underneath (not visible on this photo). Not the best solution imaginable, but it still works.
My subjective judgement is that stock B68 usefulness ends with a 100-meter mark in an urban environment with moderate light pollution, and (obviously) more in a complete darkness. Therefore I'm planning to take it with me on my next visit to the countryside and enjoy playing with it in dark night sky and scenery. Fully focused beam (although with reduced lumen output due to inevitable light losses) is tight and dense enough to produce a very pleasing "light sabre" effect even in mildly foggy air - one feature of this flashlight which is very desirable for the inner child in all of us, he he;)
B68 can tailstand with ease. I've removed the clip and plugged the screw holes which normally enter the battery compartment.
Tailcap of this flashlight is occupied by a reverse clicky switch of unknown origin and quality. Reverse clicky practically means that you need to turn the flashlight on ("hard click") and then lightly tap to cycle through modes - that if you're using a multi-mode driver. There isn't any "momentary on" with this type of switch. Outside surface of the tailcap is smooth and this could pose a problem if you tend to over-tighten it: in one instance I've ended up using a piece of bicycle inner tube to gain some friction and be able to unscrew the tailcap. Luckily I didn't have to use pliers or vise...
I don't see a way to remove the switch for inspection or repair without damaging it, since it's a press fit. I can't even tell if black plastic disc visible from inside is a part of the switch itself, or a separate retainer disc of a sort. All I can say is that switch still works, knock on wood... Switching action is firm and crisp, without any grinding or sticking. Also there's no flickering during mode change, so contact surfaces must be still clean and intact (keeping my fingers crossed on this, considering the 2.15A tailcap current). Since rubber boot is somewhat recessed - obviously to make B68 tail-standable - it takes some effort to turn the flashlight on/off if you have stubby fingers or a habit to operate the switch with your thumb only. As some specialized forums say, replacement tailcap boots are quite hard to find due to non-standard dimensions. As a preemptive measure to fight any possible corrosion/arcing/unusual wear problems that I've encountered with couple of my crappy Chinese "Police" flashlights, I've applied a squirt of fine contact spray to the inner components of this switch. Note that this is not WD40 or similar general purpose penetrating oil, but a special product intended for fine electronic components, which neither contains hard acids/alkalis nor does it attack rubber/plastics. It instead leaves a very thin protective film on contact surfaces.
I don't see a way to remove the switch for inspection or repair without damaging it, since it's a press fit. I can't even tell if black plastic disc visible from inside is a part of the switch itself, or a separate retainer disc of a sort. All I can say is that switch still works, knock on wood... Switching action is firm and crisp, without any grinding or sticking. Also there's no flickering during mode change, so contact surfaces must be still clean and intact (keeping my fingers crossed on this, considering the 2.15A tailcap current). Since rubber boot is somewhat recessed - obviously to make B68 tail-standable - it takes some effort to turn the flashlight on/off if you have stubby fingers or a habit to operate the switch with your thumb only. As some specialized forums say, replacement tailcap boots are quite hard to find due to non-standard dimensions. As a preemptive measure to fight any possible corrosion/arcing/unusual wear problems that I've encountered with couple of my crappy Chinese "Police" flashlights, I've applied a squirt of fine contact spray to the inner components of this switch. Note that this is not WD40 or similar general purpose penetrating oil, but a special product intended for fine electronic components, which neither contains hard acids/alkalis nor does it attack rubber/plastics. It instead leaves a very thin protective film on contact surfaces.
Supplied pocket clip is short and way too rigid, so I've found it only partially useful. It eventually ended up in my junk drawer, together with two gold-plated (sic!) Allen screws. Screws are thread-locked and their removal is best performed using a suitable, good quality Torx key (T6, IIRC), because average Allen key may slip and mess up the removal. Another problem is, if you decide to remove the clip and screws permanently, threaded screw holes go all the way into the battery tube, totally ruining the water/dustproofing, so I've screwed in the tips of two black polythene bead ties into the holes and cut them level with the flat surface where the clip attaches to the flashlight body. Holes plugged - problem solved!
Attaching a lanyard cord is very straightforward, since there are seven holes drilled through the tail grip ring solely for this purpose.
Until I decide to buy 14500 battery and charger, my explorations are aimed towards gaining multi-battery capability and higher voltages, while staying with perfectly safe NiMH chemistry...
As I've read on BudgetLightForum, 2/3*AA versions are possible with use of battery tubes from certain cheap knock-off hosts, but increase in brightness in a 2*AA config is negligible compared to stock 1*AA. It also seems that Ultrafire C3 2*AA extension tube (otherwise a great product) unfortunately isn't fully compatible with this flashlight due to different major thread diameter on the male side. I'm not sure, but still it's on its way from China:)
UPDATE (13 DEC 2014): My Ultrafire C3 extension tube purchased on FT arrived from China, but unfortunately it WOULD NOT WORK with this flashlight. Relevant thread diameters on both sides of the tube are OK, but thread pitch isn't (flashlight has coarse threads and extender has fine). Bummer!:(
UPDATE (19 DEC 2014): During use in the past days my B68 sustained three quite heavy knocks due to careless handling and my utmost clumsiness. Those were falls from height ranging 0.5m to 1.2m onto ceramic tiles, tarmac and terazzo flooring respectively. Flashlight still works as new. Minor dents were corrected with small files and steel wool.
UPDATE (10 AUG 2015): Finally got the Li-ion version finished! Main modifications and additions include:
1. New mineral glass lens from FT, epoxy-glued in place (buyers beware: this replacement glass lens is both wider and deeper than stock PMMA and unfortunately has a bigger focal length, so it requires LOTS of grinding, fitting & shimming to produce a desired small, crisp LED die image),
2. Increased aperture diameter of the bezel ring (in order to accomodate the new lens and to allow more light to pass through),
3. New XP-E emitter with (hopefully) higher luminance bin (from FT: the original one was ruined in a petrol de-doming fail!),
4. Stock (FT B68) 3-mode driver ("High">"Medium">"Strobe", no-memory) with Li-ion support (above-mentioned 5-mode driver went into my Dad's B68 to be used with NiMH and alkalines only),
5. Chillaramic thermal compound under the emitter board,
6. One protected JetBeam 14500 Li-ion battery (true 750mAh),
7. Rigid and pocket-unfriendly pocket clip is back on, to serve as the anti-roll device and lanyard attachment point. Note that new lens protrudes forward, so the bezel-standing capability is lost. Awful OEM gold-plated Allen screws are now gun black.
Flashlight gets warm within half a minute in High mode (gets unsafe to use after some 3 minutes, heh), but it now produces very tight and dense needle-shaped beam desired for a long throw. Not so EDCable as it was before, but IMHO still worth the work-hours and investment - mostly due to its uniqueness and "wow factor"...
Attaching a lanyard cord is very straightforward, since there are seven holes drilled through the tail grip ring solely for this purpose.
Until I decide to buy 14500 battery and charger, my explorations are aimed towards gaining multi-battery capability and higher voltages, while staying with perfectly safe NiMH chemistry...
Experiment in progress: 2*AA, ten percent more lumens but - no switch!
(Extension tube is in fact Smiling Shark SS-5002 flashlight body)
UPDATE (13 DEC 2014): My Ultrafire C3 extension tube purchased on FT arrived from China, but unfortunately it WOULD NOT WORK with this flashlight. Relevant thread diameters on both sides of the tube are OK, but thread pitch isn't (flashlight has coarse threads and extender has fine). Bummer!:(
UPDATE (19 DEC 2014): During use in the past days my B68 sustained three quite heavy knocks due to careless handling and my utmost clumsiness. Those were falls from height ranging 0.5m to 1.2m onto ceramic tiles, tarmac and terazzo flooring respectively. Flashlight still works as new. Minor dents were corrected with small files and steel wool.
UPDATE (10 AUG 2015): Finally got the Li-ion version finished! Main modifications and additions include:
1. New mineral glass lens from FT, epoxy-glued in place (buyers beware: this replacement glass lens is both wider and deeper than stock PMMA and unfortunately has a bigger focal length, so it requires LOTS of grinding, fitting & shimming to produce a desired small, crisp LED die image),
2. Increased aperture diameter of the bezel ring (in order to accomodate the new lens and to allow more light to pass through),
3. New XP-E emitter with (hopefully) higher luminance bin (from FT: the original one was ruined in a petrol de-doming fail!),
4. Stock (FT B68) 3-mode driver ("High">"Medium">"Strobe", no-memory) with Li-ion support (above-mentioned 5-mode driver went into my Dad's B68 to be used with NiMH and alkalines only),
5. Chillaramic thermal compound under the emitter board,
6. One protected JetBeam 14500 Li-ion battery (true 750mAh),
7. Rigid and pocket-unfriendly pocket clip is back on, to serve as the anti-roll device and lanyard attachment point. Note that new lens protrudes forward, so the bezel-standing capability is lost. Awful OEM gold-plated Allen screws are now gun black.
Flashlight gets warm within half a minute in High mode (gets unsafe to use after some 3 minutes, heh), but it now produces very tight and dense needle-shaped beam desired for a long throw. Not so EDCable as it was before, but IMHO still worth the work-hours and investment - mostly due to its uniqueness and "wow factor"...
Much larger optical aperture and new lens
New XP-E emitter (aperture in steel retaining disc is also widened)
Plastic shim under the bezel ring (new lens has a longer focal length)
With clip and lanyard attached
>>> to be continued <<<
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