[BLF Joint-Development] WildTrail BLF Tactical Flashlight

Thank you Anthon. I will try to consider your suggestions with the next design update. ;-)

Do we really need potted drivers if these have components only that are likely to resist multiple drops? It seems the inductor of boost drivers is a very sensitive component but with a usual AMC driven circuit risks of a broken driver may become rather insignificant.

USB charging if it does at least 2A. Otherwise drop it.
Thumbs up for the good UI.

My vote goes to The essential tacticool flashlight.

Model A +21700 for me without USB for more compact and better water resistance, Andúril with forward tail SW ,lighted E-SW.

If it’s aimed to be a tactical flashlight, I think the internal charging feature should be removed to decrease the complexity of the product. More features = more point of failures.

Also would like to see FW3A style clip to assure the steadiness of the clip.

Just my two cents.

Okay, I will try to draw a concept with rubber cigar ring and full circle ring clip mount like FW3A uses. Is bidirectional really important? Maybe it's useful to have another groove close to the head section to use the unidirectional clip in the reverse direction?

Regarding the preferences of Sofirn:

I have some history in negotiating designs with Sofirn, and despite them being one of the more innovative flashlight companies, they have a very strong preference for what technology they already have in-house. You can not blame them because developing new things is high risk for a small company. But a very important part is that Sofirn does not have a real clue what features are valuable and which are unimportant, they are afraid to develop stuff that may not sell. Unlike Emisar that has a flashoholic overseeing the designs (Hank), and I expect Nightwatch to get feedback from Neal, Sofirn does not have an inhouse flashlight fanatic that sees the value of design decisions.

But they did build the lantern which has many completely new concepts for Sofirn. This has worked because the long-term determination of DBSAR and a huge interest list convinced them to do so. Now that they have acquired the new technology they will use it elsewhere, so afterwards they do see the advantage of development.

Now about the hidden USB port: I bugged them about that before for use in a “grandma light” (18650, both USB-C-charging and a magnetic ring UI), and I got the same message: difficult and expensive. What they do not know is that if they manage to design it in a proper way (robust, elegant and convenient), they have a winner in house: very useful and flashoholics will love it.
(same goes for magnetic ring control of small flashlights, they use it on their diving lights but it needs to be made smaller for use on EDC’s, infinite variable is not even needed to make it very popular. Sofirn is very hesitant to go that way)

So my advice is not to always listen to what Sofirn thinks is feasable, if as a flashoholic you (and BLF) are sure that a feature is a very good idea, keep convincing them that it is the right thing to do; they will not have the knowledge to judge how important the design features are, you will have to point that out for them: which feature is an unimportant wish, which one is desirable but negotiable, and which features are essential no matter what. And maybe they need time and a long interest list to be pushed over the edge.

If Sofirn gets their way too much, a compromise flashlight will result (the SP70) that is in between pretty nice and meh. But if they get constant feedback and redirection by someone or a skilled team that knows what they are doing, you get very good new products.

Does Acrbeam use a dual_tube design in the L16 and L30 or another method? What about Klarus for their lights that can work from off with tail or side switch?

Thanks a lot for sharing your thoughts about Sofirn and the often long and sometimes even tedious way to convince flashlight manufacturers. Regardless of any specific brand I will not give up convincing them to invest some extra efforts in driver development, well-chosen emitters and comprehensible and sophisticated user interfaces and not only following the war on lumens. Sofirn and WildTrail are two of those brands who strive to become better by listening to our suggestions but as you said, it sometimes takes more than a just a good advice to guide them into the right direction.

Concerning this very project:

I told Jacky to please avoid using FET drivers with a tactical/tacticool flashlight like the one we're talking about here. FET is nice for posing high lumen numbers with ugly-tintshift emitters like XHP50.2 3V 5.000K (3B). Instead, I would like him to use a boost driver with a 6V SST-70 but that might increase both efforts and costs for development at least by factor 2. So, this option has been ruled out, at least for this project. That's why we have to stick with 3V emitters. In a tactical flashlight I expect something more reliable than FET, something with constant output, preferably with the option to use 2x CR123A for emergencies or the always imminent zombie apocalypse. If I was lost deep down in a cavern and my life was at stake, I wouldn't want to rely on something that comes with unstable output und unpredictable runtimes. I don't know how much extra efforts it will take to use a suitable buck driver that will work both with 1x 18650 and 2x CR123A. It cannot be that difficult as Sofirn can also offer a cheap flashlight with a good buck driver, see SP31 V2.0. I also like the UI the SP31 V2.0 uses even though I still see lots of room for improvement.

Still, it's totally uncertain where we will end up with the driver as Jacky is still looking for semi-professional / professional support in driver development. Maybe we don't have to reinvent the wheel and can use something that is tried and tested.

UI-wise there's the question if we need Andúril (preferably stripped to the essential functions incl. thermal calibration/configuration). If the answer is yes, it will take additional time and testing including the involvement of ToyKeeper. Eventually, it could be worth it as this has some potential for selling a whole new generation of (tactical) dual switch flashlights, regardless of any specific brand. I try to think ahead both for BLF joint-collaborations and the future of flashlights and their manufacturers. If the answer is no, we could do a shortcut and use something proven which should be easy to implement.

Last but not least, there's the decision about the emitter. Osram's White Flats seem to be out of the question (too much throw, too coldwhite) and require very exact focussing (see Fireflies E01 issue with Osram LED). If we aim for about 1.400 - 2.000lm there are several options:

3535:

SST-20: cheapest option but highest risk of tintshifts between green (low current) and blue (high current), small die size could result in a too small hot spot

XP-L HI / HD: might be a safe option to use

XP-L2: most efficient in terms of lumens but looks awful in a reflector but might be useful underneath a TIR lens that eliminates the "rainbow-effect" of a flip-chip design

LH351D: probably less efficient and with a high risk of green tintshift, HighCRI version will not reach the target lumen range

5050:

XM-L3: not yet available, pending further testing

SST-40: might be a safe option to use and works fine with a CC driver, 4.800K tint was reported to look well on beamshots

XHP50.2 3V: only available in 6.500K and 5.000K while the latter one is subject to heavy tintshifts in green and yellow

Regarding the “FW3A style clip”, the FW3A has the worst clip (for me) of any I’ve used. No matter what, it would not stay securely in my pocket, so I will never EDC that light. I’m guessing it’s the fault of the taper, but I’m not 100% sure. Regardless, please no taper.

I would only be interested if it had usb-c and 21700.

I think you confuse a few things here.
In my experience lineair FET drivers of the BLF-A6 type are extremely reliable: they are simple, I had never heard one fail (except some that were sloppily produced), and only having small shallow components they are extreme impact-resistent. The output is not instable, it is a very predictable slow decline in output warning you in advance of battery depletion. Give me a light with lineair FET driver any day in that cave :slight_smile: . The most reliable tactical lights even do not have any regulation, just one or two current limiting resistors, so again a steady decline of output but ultra-simple/reliable.

For an emergency I rather carry an extra 18650, and CR123 cells are only abundant in the US, and after the zombies here in Europe you are more likely to run into a 18650 battery pack than into a stash of CR123’s.

...or I was just using the wrong words to express what I really meant to say. :FACEPALM: I'm afraid I need to take some more English lessons. ^:) Instead of "reliability" I meant "sustainability" or "permanence" of the flashlight's output. I agree that FET driven lights are very reliable with regard to possible failure.

This is exactly the situation I don't want to face when being lost in a cave. I want to have a steady output as long as possible. :-P

You mean it’s ok if your light to suddenly just trigger its LVP, in a cave? Haha…

My point was about the clip is being secured by the tail cap, not detachable like pictured on first post. I should have wrote more detail.

I’d be interested in Model C.

A 21700 tactical light would be interesting, and has not been done.

Dual springs + foam/rubber washers to protect cell from impacts/recoil in line with the tube.

Momentary switch, 500-800 lumens (whatever will run for at least an hour without thermal problems or dimming)

Preferred UI would have no mode memory, and a hard-to-access very low mode as well. A generic streamlight momentary switch UI that goes H-H-H-L with no memory would work and be difficult to accidentally activate low mode.

I think the idea of not wanting a FET-driver is that you rather have a lower output but constant and longer. The longer runtime and lower output can be had with a FET driver also, by adding resistance in the circuit (not often done but is a solution for those modern low voltage leds). This is just to point out that long runtimes and FET-driver can go together, but I do agree that current regulation is nice (which in a lineair driver is also done by adding resistance but it varies depending on battery voltage, to keep the current constant).
A boost driver is a different beast, I have not much experience with those, but I had one fail (a KD boost driver wrecked a XHP50.2 in one of my builds)

I have faith in the driver developer's or firmware programmer's creativity to indicate a depleted cell, e.g. by a blinking LED, followed by a hard stepdown to a low mode.

Meanwhile, I tried to reflect the desire for a more compact design with a closed ring clip mount and a rubber cigar ring (see revision 2), still not yet fully downgraded to 18650 size. Maybe 21700 is not so bad either. ;-) Using a TIR optic should hopefully save some space in total length. Provided that we go down to 18650 size, I wonder if a Carclo 10507 with 3x SST-20 or 3x XP-L HI would be as interesting as a single SST-40 with regard to throw numbers, power consumption and runtimes.

Model B.

Notes: around FW1A size or would be nice (though probably not doable with a tail click. But at least as small as possible without further bulking it up with USB charging.

@Dual switch: If you have don’t have an e-switch on the back you need a clicky there. To my understanding: If you want this to have an always high or turbo momentary, it’s key that there is no mode memory or mode memory being able to get disabled/set to a user-configurable value.

That would be a solution I can live with though in my eyes not ideal (I still prefer rear e-switch) but I would definitely buy it if it’s a lot shorter than e.g. an Olight M2R.

@kanton: If we use an e-switch in the tail we probably need to go for a double-tube design. This would come with a big trade off in terms of higher impact / wear sensitivity and more complexity at higher costs. Regarding your prerequisites about the UI, I think the draft UI I posted in the OP should take mode memory on/off into consideration. Of course, any suggestions how to improve it are deeply appreciated.

You can have an eswitch in the tail with a driver-in-tail design. That necessarily means PWM, though, and something like 98% maximum on-time (thus ~2% off-time to supply power to the driver), and a small resistor across the LED to complete the circuit when the LED’s off.

Main concern, though, should be how to differentiate this light from all others already out there, so it’s not just another “me too!” light.