Review: FandyFire K2 1x26650 XM-L U2 Flashlight

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Review: FandyFire K2 1x26650 XM-L U2 Flashlight

FandyFire K2 (1x26650, XM-L U2)

Reviewer's Overall Rating: ★★★½

Reviewer's Mod Host Rating: ★★☆☆☆

Profile

 

Summary:

Battery: 1x26650 or 1x18650
Switch: Side, Electronic
Modes: L 20%, M 50%, H 100%, hidden Strobe and SOS, no memory
LED Type: Cree XM-L U2 (est. 1A or 1B tint)
Lens: AR Coated Glass
Tailstands: Yes
Price Paid: Review sample from DX, reg. price was $29.90
From: DX
Date Ordered:

 N/A

 

Pros:

  • comfortable to hold, fits well in the hand
  • Good heatsinking
  • Large emitter star
  • Excellently finished reflector, super smooth
  • Excellent machining overall
  • Perfectly centered emitter
  • Stainless steel bezel

Cons:

  • Somewhat underdriven, with still respectable output
  • Poorly spaced modes; Med and Low are both too bright
  • Very visible PWM in Med and Low
  • Hidden strobe/SOS cumbersome to exit once entered
  • O-ring is way too large, needs guidance when tightening the body
  • knurling is sparse and not aggressive enough, so the grip is somewhat slippery
  • So far, appears to be not mod-friendly

Features / Value: ★★★½

Design / Build Quality: ★★★½

Battery Life: ★★★★★

Light Output: ★★★☆☆


Overview

The FandyFire K2 (there are other branded variants) is a recent entry into the 1x26650 flashlight market. While there are quite a few options already out there, not many attempt to emulate the 4xAA compact flashlight (like the EA4 or D40A). The K2 appears to attempt that, and I think it does an OK job. However, there are a few reasons Nitecore and Sunwayman should not feel too threatened by this one.

From the outsode, this is a nice looking light.  The machining on the light is excellent.  No sharp edges and no machining marks to be found anywhere.  The anodize is very good, on par with the EA4 and D40A (probably very close to HA III) with no dings or scratches even after moderate use (two battery cycles so far). 

standing

Tailstand is not a problem, a nice wide base. There is a lanyard hole near the tail.

tailstand

From the front, we see the perfectly centered and spaced emitter. The reflector is perfectly finished with no signs of machining rings or marks.  It was dust free when received, and I really didn't want to open it up and soil it. The picture is showing some bezel reflections from my studio front-light (aka warm white flashlight).

front

The tail end features an X-pattern which is flush with the outer ring.  Tailstand is very stable.  The tailcap appears to be glued, as I could not remove it with hand force. This is not really an issue, since it should never need to be removed.

tail

 

As a 1x26650 light, the handling is good.  It fits very well in my hand, although it could use a little more grip.  The minimal knurling is not very aggressive.

in hand

in hand2

The light comes apart between the body and the head. It ships with a nice 18650 sleeve that does rattle when used.  The body tube is very thick (4.2mm).

It's not obvious here, but I found out when reassembling the light that the O-Ring diameter is too large for the light.

part

Here's what happened the first time I tried to reassemble the light.  Fortunately I noticed before severing it completely.  getting the O-Ring to go in properly requires a series of small turns each followed by pushing the O-Ring back into the groove.  Once it goes far enough, the O-ring stays in place and everything is fine from there.  I find this to be a let-down, and not sure how this could have been unintentionally overlooked during manufacture.  On the bright side, once the light is assembled, it does still appear to be waterproof at that joint.

O-ring pinch

The threads are well cut, very smooth, trapezoidal, and were adequately lubed.  They are nicely anodized, allowing for tailcap lockout.

threads

Tearing this light down was met with limited success.  The tailcap is glued, so at this point I cannot get in there and assess the spring quality (although visually it looks fine) and make a spring mod.  There is enough compression to allow a protected 26650 (TF Flame) to barely fit without crushing anything.

spring

Onto the head end.  Opening up the head at the bezel allows access to the lens, O-ring and reflector. The teardown hits a snag here, as you will see. 

head parts1

The head is made of a tube (thinner than the body) with a large pill pressed in or screwed in, I have not determined which yet.  The large thick emitter plate is screwed to the pill and uses thermal paste underneath. 

emitter

There is also some adhesive holding the switch side of the emitter plate, seen in the image below. I believe it is a potting compound or adhesive for holding the switch itself. This made it difficult to get the plate up to look underneath.  When I finally did get it to move, I found out the hard way that there is no slack in the emitter wires.  The positive wire snapped when the plate came loose.  Underneath there is a small central hole, but the pill itself seems thermally adequate.

under emitter

How well the pill is connected to the head remains to be seen, but I could not move it at all, so there's something holding it.

Onto the driver end it is a similar story, no entry.  I could not get the driver out.  I tried to push through the hole under the emitter as well.  The driver remains in place... for now.

driver1

The driver appears to be a constant output type, in a buck configuration.  Between 4.2V and aproximately 3.5V, the output is constant brightness with varying tailcap current.  For example, at 4.2V, the tailcap current is about 2.0A. At 3.6V, the current is 2.5A.  Below 3.5V tailcap current falls off as the driver enter direct drive mode (no more bucking required).  This tells me that emitter current is regulated right around 2.5A (which is the spec from DX).  Until I can get the driver out, it is unknown if a resistor mod is possible, but I suspect it is.

Note:  Using 26650 cells in this light has produced some flickering, and I have narrowed down the cause.  The inner thin white ring of silkscreen shown above on the positive contact plate is raised just enough to hold the wide 26650 positive button off of the copper plate.  This is intermittent but will happen quite often.  I am not sure why that silkscreen ring is there, what purpose it was supposed to serve.  Using 18650 cells is not an issue due to the smaller positive contact.  One solution would be to scrape off the silkscreen ring. Another would be to add a low profile solder blob to the center of the board.  I'll probably go with the latter, but protected cell users may not want to add any extra height.

 

 Packaging and Accessories

The light ships in a plain cardboard box with cutout foam for protection.  All sides but the top are well protected.

box

 Most lights I get come with a thin wrist strap I'll never use, and this one is no exception. There is an additional O-Ring as well, just as loose as the one installed.

a


User Interface

All modes are accessed via the single electronic side-button.  The button has a nice feel with a translucent silicone boot.  The cover is translucent to provide feedback tot he user in the form of green and red status LEDs.  But first, the controls.

The main mode group is accessed by clicking the button.  Single clicks cycle through Low - Med - High - Off.

The disco modes are accessed by holding the button for ~1.5s while the light is on. Once selected, single clicks cycle between SOS - Strobe.  Unfortunately, there is no access to Off in this mode group.  You must hold the button to get back to the main group to turn the light off.  On the bright side, at least these modes are hidden.

Another related issue, Strobe should be easier to access, maybe through a quick double-click would be good.  Right now you have to turn on the light, hold the button to change groups, then click once to move from SOS to Strobe.

Moving on to the status LEDs, which are used to indicate battery condition.  These seem to have been well thought out.  There is no status indication while the light is off. 

While on with a battery above 3.0V, the button glows a dim green which indicates a good battery status.  So dim in fact, I was not sure it was working when I first tired it.  However, in dark conditions the green is a very nice level. Not overpowering or distracting, just obvious that the battery is good. 

This got me thinking that the red low battery indicator would be too dim.  When the battery voltage drops down to about 3.0V, the button turns a bright red.  If you are looking in the general vicinity of the light, you will notice it.  Once a low battery has occurred, the button will latch red while on, until the battery is removed.  This is good because Li-Ion cells tend to self-rebound some voltage after the load is removed, but the cell is still depleted.  the latch makes sure that you know right away the next time you turn on the light.

As the battery drops further, at around 2.7V the button stops glowing red and flickers periodically along with the main emitter.  The main emitter flickering is very obvious, but the pulse is so quick you do not lose focus on your target.

Once the battery gets to about 2.5V, the light turns off.  The light will allow turn on if the cell self-rebounds, but the low battery status is maintained.

 

Compared to:

Here's a shot of the K2 next to what I consider alternatives, the EA4 and D40A. This shot was taken later, so please excuse the quality.  THe K2 is longer and about the same diameter ans the other two.  I will note that on my sample, the body tube cutouts align very well with the switch position. I'm not sure if this was intentional, but it is nice.  Something I never noticed on the SWM D40A until now is how the body features do not line up with any design features on the head.  Mostly aesthetic, and possibly unintentional, but I like that my K2 does line up. Handling would be ever so slightly more awkward if the triangular tube cutouts were misaligned with the head.

compared

 

 

Beamshots

Here are some white wall beamshots, 1m distance, high, med, and low. The hot spot is well defined with a typical XM-L corona.  There beam is very smooth with tiny rings close to the hotspot when on a white wall within a foot or two.  Definitely not noticeable during normal use.

Camera settings the same for all three; 1/20s, f/8, ISO400, Daylight.

High:

beam high

Med:

beam med

Low:

beam low

Measurements

Dimensions:

  • Overall Length: 128.6mm
  • Bezel/Head Diameter: 41.1mm
  • Body Diameter: 37.6mm
  • Tail Diameter: 39.0mm
  • Reflector Inner Diameter: 33.5mm
  • Reflector Outer Diameter: 37.8mm
  • Reflector Depth: 27.1mm
  • Reflector Emitter Hole Diameter: 7.5mm
  • Lens Diameter: 38.0mm
  • Lens Thickness: 1.9mm
  • Emitter star diameter: ~25mm
  • Emitter star thickness: ~2.0mm
  • Driver diameter: ~33.6mm
  • Pill inner diameter: Unknown
  • Pill inner depth: Unknown
  • Pill outer diameter at threads: Unknown

Weights (without batteries):

  • Overall: 194g
  • Head: 98g
  • Body Tube/Tailcap: 96g

Performance (stock, TrustFire 26650 Unprotected, 4.1V, uncalibrated test equipment):

  • Light Output: ~672 lumens at start, ~634 lumens after 30 seconds
  • Beam Intensity: ~15.7kcd

Power Source Options: 1x26650 or 1x18650 unprotected or protected cell, raised positive cap. (note: possible contact issue with wide-topped 26650 cells)

Switch type: Side, electronic, with indicator LEDs

Modes: Low (0.18A), Medium (0.83A), High (2.0A), hidden SOS and Strobe

Mode Memory: None, starts in Low

Standby Current: 1.2mA, rather high. Recommend removing the battery or using the physical lockout capability when not using the light for a long period.

Conclusions

With the exception of a few issues (O-ring, battery contact, Low frequency PWM, simplistic user interface), the FandyFire K2 is a  well built light.  It has very good finish, an excellent reflector, and is a nice looking light.  As a 1x26650 tube light, this is one of the nicer ones I've seen.  As competition to the Nitecore EA4 or Sunwayman D40A, the only advantages it has is price and (for some) Li-Ion support.

As delivered, cautiously Relic Recommended, for those willing to:

  • replace the O-ring,or live with it, as I will
  • address the positive end battery contact issue, either with a simple mod or cell selection

As a mod host, for now it is Not Recommended. With no easy access to the driver, and difficult access to the emitter there's not much a modder can do. An emitter swap is possible, since the star could be desoldered and reflowed.  With a thicker than average star, replacing it with a Direct-bonded version will present mechanical challenges.

Once it's figured out how to get the driver out, the modder status will likely change to recommended.

Thanks for reading! searchID8934

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Edited by: sb56637 on 09/02/2017 - 11:54
relic38
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Reserved.

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MRsDNF
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Thanks for the interesting review relic38. I’m curious to see if this is all glued together. Looks like a nice light though.

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

leaftye
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relic38 wrote:
Note:  Using 26650 cells in this light has produced some flickering, and I have narrowed down the cause.  The inner thin white ring of silkscreen shown above on the positive contact plate is raised just enough to hold the wide 26650 positive button off of the copper plate.  This is intermittent but will happen quite often.  I am not sure why that silkscreen ring is there, what purpose it was supposed to serve.  Using 18650 cells is not an issue due to the smaller positive contact.  One solution would be to scrape off the silkscreen ring. Another would be to add a low profile solder blob to the center of the board.  I'll probably go with the latter, but protected cell users may not want to add any extra height.

Thank you for figuring this out.  I'll add a solder blob tonight.  The slight reduction in tube length is worth it to get rid of the annoying flicker.

I love the feel of this light, but as with many lights, the driver needs a lot of improvement.

If there's room enough for a floating pill, I'll be looking to order custom contact plates.

The low mode should be lower.

RaceR86
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A really good review Relic38! Thanks!

Despite that it does not seem to be that mod-friendly, im still highly considering it. It looks really good! Smile And it might be a lot of potential in the light.

Do you plan on going more brutal on the light in order the try and get the driver circuit out, or do you plan to leave it as it is?

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Nice review. Do happen to have a Rook? How does it compare beam wise? Thanks.

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R86, I will get the driver out some day. Whether I figure it out or someone else, it will come out.
fishmaniac, no rook here. Beam is good, hotspot well defined and larger than on a C8 or even the EA4 hotspot. Spill is even with a bezel reflection just outside of the spill, creating a ring.

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Thanks a lot for the review! Frontpage’d and Sticky’d.

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relic38 wrote:

As a mod host, for now it is Not Recommended. With no easy access to the driver, and difficult access to the emitter there's not much a modder can do. An emitter swap is possible, since the star could be desoldered and reflowed.  With a thicker than average star, replacing it with a Direct-bonded version will present mechanical challenges.

Once it's figured out how to get the driver out, the modder status will likely change to recommended.ID8934

 

Got my light today (thanks to Relic38 for giving me a few answers about this light before I ordered it).

I seriously LOLed when this happend, it was like dejavu. I tried to lube the O-ring, did not work. Its actually the same O-ring on the body that is on the front between reflector and lens. I just removed the O-ring on the body, I will replace it.

The reflector is exactly the same size/look as the reflector in my Fandyfire Rook.

Emitter was partially attached with some thermal silicone/glue or something. You can see it on the upper part of the MCPCB. All the other white stuff was thermal paste.

 

The thermal silicone came from the top of the switch, which is the oval hole in the mcpcb. I tried to removed some of it.

The driver circuit have good space on the sides for a flat screwdriver.

It was stuck, but I got it out quickly on the first try despite that there was some silicone on it that attached it to the body. My experience with various SRKs might have helped. Or maybe I was just lucky that they did not use too much silicone.

This is how the empty pill looks from above. If you have issues getting the driver out, giving it a push from the switch might help,preferably combined with trying to drag it out with a screwdriver.

 

I measured emitter current to be:

0,21A, low

1,01, medium

2,38, high

These numbers seems to be higher than the ones posted by Relic38. I used a Soshine 26650 @ 4,05V. I can not say if the difference are due to DMM, or due to slight differences in components on the driver circuit. For most people, stock output was pretty decent on my unit.

I tried playing with the R010 resistor, but I probably broke something. Output is now close to nothing. I basically put a wire over the resistor. 0:)  I have no clue if that resistor actually were limiting current. Probably should have asked here first. Silly Its not an issue though.. I have a new DrJones driver who is in need of a home. Smile Changing the driver was my intention from the day I ordered it.

As for stock UI, its miles better than the UI in say, the Supfire M6 IMO. Having hidden strobe and SOS in its own group is nice. UI is far from great though. I could probably live with it if it had more "oomph" on high! Wink

As a mod host. I think its good. It seems like heat transfer to the body is great. MCPCB screws down. It can fit a 20mm copper star. Reflector does not easily crash in the emitter wires (this happens on some lights when you go from 25+mm MCPCBs to 20mm) As for Sinkpad being less tall than the stock MCPCB by about 0,35-0,38mm. I dont think that is an issue. Because the reflector can go all the way down to the pill when there is no MCPCB in there. 0,35mm is close to nothing. In worst case, add on extra O-ring on the front, which was included. But I doubt that is necessary. A Noctigon is less tall compared to a Noctigon. Sinkpad probably preferred due to being more similar in hight with the stock mcpcb.

The driver compartment is also decent sized.

I really like the size and feel of the light. Anodizing seems great and it came with an AR lens.

That is my first impression of the light. Hopefully some will appreciate it and also find the information about modding useful. Smile

My light came from Lightscastle. This was basically my winning price from the build from scratch contest! So thanks to them, Old-Lumens, and everybody.. Smile

I got myself a nice host! Smile

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I’m not a big fan of this form factor but I really enjoy this style of review. It was a pleasure to read, and answered all the questions I had and several I didn’t but should have. The extra info from RaceR86 was a nice bonus too. Silly

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Thanks for the info RaceR86. Nice pictures. So using the DrJones driver you would use the OEM switch?

 

djozz quotes, "it came with chinese lettering that is chinese to me".

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leaftye
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@RaceR86, are you doing a mod thread when you install that driver?  I'd like to see how it's done with this type of switch.

 

I can't find the right size o-ring to swap.  The closest match I could find was 29x2.5mm.

The low mode should be lower.

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Thanks for the great info R86! My measurements were tail current, and I think they match well with your emitter current. Needs more drive on high, for sure.

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leaftye wrote:

@RaceR86, are you doing a mod thread when you install that driver?  I'd like to see how it's done with this type of switch.

 

I was not planning to, but since you asked...

Mod thread here.

It should answer most questions... Smile

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Just got an FF K2 from WallBuys, think it was an instant kill, paid $22. Really liking it so far though. Same excellent packing, the o-ring seems ok so far - doesn't seem loose, UI is the same, exactly as described, a real AR lens (wow - unusual for a FandyFire).

I measured:

-- On A KK ICR 4000 button top at 4.14v, at the tail 2.36A:

 lumens: 799 @start, 785 @30 secs, throw: 22 kcd

I got better #'s than Relic38 across the board. Not sure, but maybe I just got CREE lucky and/or it likes the KK cell better. Got similar results on a Samsung 20Q (low resistance). Really liking this light though - the size, feel, side switch, and the modes aren't so bad. This is the 3rd side switch light I got in the past week (SupFire M6, Convoy L4) and it's sure making tailcap switch lights feel awkward and cumbersome.

The XP-11, K2, and M6 make an outstanding set of comparable light in 3 distinct sizes. I'd say the K2 fits perfectly in between in width and length.

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I received a solarstorm k2 from blackshadow a week ago. I have zero gripes about this light. The ui does not bother me at all after becoming annoyed with the supfire m6. As long as the strobe and sos are out of my way then I am happy, I will never use them. And 90% of my other budget lights contain annoying disco modes that you have to cycle through sometimes. I don’t mind the low start, it only takes a second to click up to high.

No issues with the o-ring. This light is so solid and feels great in the hand. The machining is perfect and the anodizing looks high end. I love the side switch and glowing green button.

I almost gave up on 26650 lights after buying the trustfire a8 and ultrafire version. Those two lights were awkward with their size and tail switch. Plus the overall quality did not compare to the k2.

I’m glad i purchased this light.
I have to agree with Tom. After handling this light for a few days. I don’t feel the urge to handle my
tail switch lights anymore. For some reason my solarstorm k2 appears to be just as bright as a convoy m2 running nanjg at 2.8ma.

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785 lumens is sort of amazing for an XML U2 at 2.4A, and on aluminum? Something fishy there - Got to open mine up and check, but maybe the alum star has a direct thermal path, or they upgraded to copper. The lens and reflector look perfect though, and the low profile SS bezel helps too - from other posted test results on black vs SS bezels and their size. Actually looking at it compared to an A8 is night and day - A8's output has got to be suffering from the infringing deep bezel while this one is wide open. This light competes well with bigger, better driven stock C8's.

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I think the A8 could be as bright as the sun and I still wouldn’t care for it. Just an awkward size with a tail switch. I’m becoming a side switch snob now.

Is there any differences in the solarstorm and fandyfire k2? My solarstorm came with the little plastic ring removed from the driver/battery + contact board. And the O-ring fits perfect. Maybe the workers stretched a few o-rings in the past during installation, causing the loose fit.

I’m fine with the output of the K2 as is. I love the feel, look and anodizing. And that little glowing button.

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I bought one of these a few months ago and love it.
Seems to last long enough on a panasonic 18650 3400mah and it throws really well considering the price. I can easily light up houses at 200m and the battery indicator light is really helpful/neat.

The finish on it is on par with my supbeam k40 and 100x better than the cheap cree c8’s i have. I have dropped my k2, 3 or 4 times out my pocket whilst on my motorbike ( ie. from a few feet up at speed on to tarmac ) and it has survived well, althuogh there are one or two chips in the finish now Sad

Overall fantastic light and worth every penny I paid. ( £15 gbp )
For the price i cant find a torch as bright, that throws as far or with as nice a finish for that price here in the uk.

Mine was listed as solarstorm but seems 100% identical to the fandy fire.

Rex

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Pretty sure the Solar Storm and FandyFire K2's are identical. Dunno, but somehow they get the max out of this XML emitter in this light for the amps it uses. Yes - 22 kcd I measured is 296 meters for 1/4 lux (moonlight).

Update: This evening, I decided to go ahead and take a looksy, which turned into a full take apart. I can confirm my FF K2 does have the same LED star and pill design, including the hole in the middle (wuz up with that?). I was able to pop out the driver with pressure through space by the switch using a solder pic tool. It was glued in, probably by thermal adhesive. I was also able to pop out the aluminum pill easily with a little force from a hard push from a finger. It could only come out one way based on the cut out for the switch, so it was pushed towards the battery end.

I believe the R010 resistor is a current sensing resistor because it's not wired directly to a LED wire, but goes thru a couple of FET's (3 legged things...). I'm going to go a little mild on a resistor mod that would get maybe 30-40% increase. I think 4A+ is too much for this little guy - the reflector is heavier than the pill, and the body is quite thin. All the weight of this thing is in the battery holder end and the reflector -- quite weird... I'd like to keep the stock driver - the UI isn't awful awful, and nice to keep the green and red LED's active for a battery status.

Tom E
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Thinking a R020 would give a 33% boost on top of the R010, so will give that a try, if I got one...

relic38
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Tom E, I think the light may have been updated. The driver seems to drive more current on hours. 2.4A at the tailcap on a fully charged cell is closer to 3.2A at the emitter. That would explain the bump in output. I think the reviews do get back to the manufacturer and that may be why many of my negatives (O-ring, drive current) are addressed. DX sponsored the review, and I have no doubt they would read it and want to address the problems. If I am right with the assumption, the one thing they missed was posting here that changes were made and sending someone an updated light. Opportunity missed, IMO.
Anyway, glad to hear that the light is improved.

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Ohhh, good point, thanx Relic38!! I did notice one resistor value that differed from the pic RaceR86 has in post #8 -- it's the 103 resistor just below the yellow cap - can't recall the new value but it's much smaller (from 10K). Also all the epoxy Racer86 ran into around the switch is not on mine - easier to remove the driver and pill because of that, maybe.

Also that white disc on the button shown in his pics fell off on mine, but think I could just epoxy it back on easily.

Looking at the thickness of the stock MCPCB, I'm going to add a copper disc under the Noctigon to re-produce the height as close as possible. I'll reflow the disc to the star, and then can re-use the hold down screws, so this should really help with thermal issues, at least in the most critical transition area.

Also will definitely do an amp measurement to the LED while I have it all apart to confirm this, before doing any resistor modding. There really isn't much heat sinking in this light in the critical areas of the pill and MCPCB and I'm not that good with metal work to do much with it.

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I have spoken with the manufacture before and mentioned that they should build a 4xAA light with similar looks and build quality to the Solarstorm/fandfire K2. Add XM-L2, Keep the similar looks and glowing button. But make it a little fatter, machine channels in the tube for 4xAA without a dumb carrier.

They said that they might start the designing process after their new year holiday. I told them to pick up a sunwayman d40a as inspiration. I guess we will see.

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Stacked 2, then 3 R075 resistors (lowest I had) on the R010 and it had no effect whatsoever. Under a loop, it looks like the solder connections are good - dunno why this didn't work, because it should get a 20-35% bump. I'm reading about 2.9A at the LED, open on the bench, basically same value before adding any resistors, might have gone up from 2.8A - not sure. Gotta take another look - wish there was some way to measure the resistance of these resistor stacks - always seems too low for my DMM, even a fluke. The R010 just seems to stand out as a current limiting or sensing resistor - nothing else looks even close on this driver.

Update: All Done!

I re-did the resistor soldering and seemed to be getting 3.1A to the LED with the 3 R075's. So, left it at that. Upgraded the wires to 22 gauge, added some AS5 in the body where the pill slides tightly in to, added 2 dabs of Fujik epoxy to hold the driver in. Also added a dab of solder on the driver for the + battery connection. Tried the same KK cell - now read 3.1A, hhhmmmm. Buttoned up, looks good and bright.

Note: Got a XM-L2 U2 1A on a 20mm Noctigon, reflowed on a 7/8" 22 gauge copper disc. Sanded down the star and disc to minimize height, maybe 0.1mm higher than stock. Re-used the screws, used AS5 on sanded surfaces to 2000 GRIT.

Measured:

lumens: 1,088 @start, 1,064 @30 secs, throw: 34 kcd, 369 meters (measured at 5 meters)

Not bad for being moderately driven at 3.1A, wish I could have gone higher of course Smile. The button green/red lights still work of course because it's the stock driver. Putting in a e-switch based Nanjg driver would lose the switch lights I would think.

relic38
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Great work Tom E! Maybe I will get doing something with this light someday. I think the current path could be adding up to additional resistance. Getting over 1000 lumens OTF is quite good as you have it.

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There's more...

MNKE IMR 26650: 3.4A tail, so better #'s but losing 100 lumens at the tail. So, tried my best battery: Powerizer:

Powerizer 26650 @4.18v, 3.99A tail, and that did the trick: 1,248 @start, 1,214 @30 secs

Thoughts

  • the driver doesn't seem to regulate well because low resistance cells get a higher tailcap amps reading, higher lumens output (maybe because of my resistor mods?)
  • weird, but the Powerizer seems to compensate for the resistance of the tailcap spring pretty well (not much if any drop). I assume though as the Powerizer drains and loses voltage, droppage is more significant becuase the spring's resistance will kick in
  • Run this light on a Powerizer!! Gotta order more - I have only two
  • The glued tail really sucks on this light, as so on others. If I could get the tail loose, I could copper braid the spring, though the tail spring is an odd ball in that it seems held in by the tail cap tightened  (and glued) to the body.

Pieces:

 

New setup of the LED/star. Noctigon reflowed on the copper disc, then disc and pill top sanded smooth, AS5, and secured tight with screws.

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I wonder where @Relic38 has been, haven’t seen him post since last year.

That Canadian flashlight guy & Lantern Guru -Den / DBSARlight

YuiRui
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good

XHP70/XHP50/IR-850NM

twinclouds
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Tom and Relic38: How do you guys measure the lumen values? I built an simple IS. It works pretty stable to compare different flashlights but I just can’t determine the absolute values.
After I used the sun method to calibrate, the measurement results are very low (~250 lm for U2 at 1.5A). It could be my lux meter not accurate but cannot be that much off, isn’t it?

Twinclouds