Doesn't seem like you can easily disassemble the head to get access to the ring. I had used nano-oil on the Lighten7 M1B's control ring but it just doesn't feel the same. Grease is definitely preferred on these rings. I'll ask L3I whether the control ring can be accessible or not and also mention to remind the factory to apply grease.
Cheers,
Tim
I’m right here 
. I’m actually going to China next month so I’ll be able to see what they do in person. Also they told me the spring has been changed from 3mm to 3.5mm? Makes it higher resistance to twist the ring, less prone to accidental activation .
Size comparo pic added.
Jason, based on my sample, the detents have a very nice and solid feel. IMHO, there is already enough resistance in the ring so I don't feel accidental activation should be a concern but if they think it will help, by all means. Improvements are always welcome! :)
To clarify your K40 has the 3.5mm spring, it is changed from experience of customer complaints
Indoor shots (5m) now added. Design & Features section in progress.
Hey Tim:
Do you think IMR cells will make any difference in performance?
Thanks!
IMRs are usually meant for situations where each cell needs 5+ amps.
This LED is run at 3.5A, which means each cell has to deliver 1.17 amps.
Therefore no, an IMR will not affect the brightness of the light. It will however, mean you have reduced runtimes because IMR is a different chemistry to LiIon and has less capacity.
Hope this helped.
slewfash is right on both counts, w/the batteries in series, each cell only needs to deliver 1.17A so there wouldn't be any benefits and as a matter of fact would have worse runtimes (I unfortunately no longer have 3 x 18650 IMR's so can't conduct that).
All, as an update, this review is just about wrapped up (still need whitewall & outdoor shots). This is a fantastic gem from L3, can't wait to see what else they might be working on. :)
Cheers,
Tim
I agree Tim. I honestly think for the $108 and change that I spent on this light that I can’t think of any light in this price range that gives you the quality features or the throw in a XM-L flashlight with a pretty good size head as the K40. Once the battery carrier issue is resolved to fit Xtar batteries, I’ll give this light a 9.5 on a 10 scale.
Hey Brad, did they say they were fixing the Xtar 18700 fit problems? I'm really interested in getting one of these...
Doing my best to get it figured out but it’s not goin be easy. The Xtar batteries thing isn’t a deal killer, it makes the carrier a lot tighter but not impossible. The X40 Triple U3 ( 
) Is going to have a new battery carrier which should be wired in parallel and the light is going to be rechargeable. Testing to see if it works in the K40.
As pointed out in the Fit & Finish section, what might be potentially contributing to the tightness of the batteries is loose heat-shrink wrapping on the legs of the carrier. I'm copying relevant section here so you don't need to dig through OP:
Last but not least, the heat-shrink tubing around the legs were not fully shrunk thus causing some lumpiness which can steal precious room away for the batteries to fit tightly towards the center:
Brad, can you check if you might have that issue? If so, a once over with a hair dryer should take care of that and then give the batteries another shot (double-checking that both the labels and the PCB protection wire are not facing towards the tube).
Cheers,
Tim
Whoa! You can’t just drop that bombshell with just a little wink. When can we expect to hear more about this?
Nice review as always. My god, it looks like L3 hit this one out of the park on their first time at bat! Simply gorgeous light!
Did you get it on your IS to see if the rated lumens match real world output?
Thx! With my PVC LMD, I got 1200lms @ 30 seconds w/RL3100's and 1190lms w/AW2600's.
Tim that’s a great observation and great idea regarding the shrink tubing
That didn’t work.
I think it might be better if the shrink wrap tubing in the middle post was completely removed.
Darn, ok, so just large batteries and tight tube. :)
BTW, DO NOT remove the heat shrink wrapping! Those legs carry electrical paths; the three outer ones carry the negative and that center one is critical and must always be protected as it carries the positive. I mean if you use protected cells, it should be fine but best not to test out the protection circuit unnecessarily... ;)
Cheers,
Tim
Yea I left well enuff alone.
@DARCANGEL, here's a quick summary between K40 vs. TN31:
EDIT 11/18: I retook the indoors 5m pics and have updated the pics below so that now they are a true 1:1 comparo.
They are just about identical in quality / construction. Beyond the subtle styling differences, the K40 is:
- more compact owning to shorter reflector (51mm vs. 64mm)
- slightly less throw (77k lux @ 1m vs. 87k)
- just slightly less output (K40 left @ 1200lms vs. TN31 right @ 1270lms as measured on my PVC LMD - not really distinguishable by eye)
L: K40 | R: TN31
- although it doesn't look like it due to the intensity of top shots (@ 1/4" & bottom @ 1/80"), the hotspot is slightly larger (which becomes more noticeable > 5 ft.); overall spill is slightly larger:
L: K40 | R: TN31
- much cheaper price wise
- lacking a SS bezel
- features different AR coating (K40 is geared more towards blue wavelengths)
Here's a quick side-by-side I just took @ ~1ft (ISO80, AWB, f/8 & 1/320 for left | 1/4000 for right):
K40 left | TN31 right in both pics.
Hope that helps.
Cheers,
Tim