I was thinking of doing a teardown video of it, but I guess I might not if parts are glued. With the amount of people getting this light- several of them for review purposes, I’m sure someone will do it anyway.
i hope most people find my pics helpful and doesnt damage their lights just for curiosity…
After almost a month I finally got mine. I bought it before BLF group buy but they sent me aluminium case as well. First imprssions - it’s slightly bigger than I thought, maybe it feels this way because I have small hands. Anodisation is perfect. I’ve seen smoother magnetic rings but it’s not that bad. Changing modes is inconsistent, sometimes it’s quick but sometimes there’s slight delay (when flashlight is off between two positions). Lowest mode is definitely more then 0,9lm, I think more like 3-4lm. And finally … it’s bright. It’s crazy bright! I turned it on in the middle of the day and still got blinded. It’s also well focused (which is good), I was afraid it may be too floody but it’s not. Great light, for ~$100 simply a bargain.
I posted a look inside on my blog… http://m4dm4x.com/2014/09/01/inside-the-acebeam-k40m/
I will open a thread here also for better discussion 
Im working on a review as well. but the light drops almost 20% output in 9 minutes...
I recorded the lux every 10 seconds. there is bigger drop at 1 minute, and after that it keeps dropping... I imagine it even kept dropping a bit after the 9 minutes... but very slowly
maybe temperature related?
Did you notice it go back up? Because in my videos it shows the light get brighter.
Check out this video.
hey guys!
is there a easy way to measure amps drawn?
calculating the delivered Watts to compare mod/stock should be easy then…
I am not sure if it’s save / correct just measuring across the tail switch…
( what are that chips for?)
Acebeam creates good lights but some of their flashlights (like my K50) have too many fancy features and I dare not to tear it down or mod it. I appreciate people taking the risk to do teardown and review of their lights for the benefits of this community, but at the same time I hope people can be extra careful when tearing them down, just some thoughts.
one has to take it for the team…
and if I make a mistake others can learn and make it better
Here the pic Im going to use in my review....
Click on the picture to a larger size, to see the details... you can see the Lux as well as the time...
(timer of my remote controller isn`t exactly 5 minutes... so at least you can see it turned off at 1:05)
The easiest way is to measure amps at the emitter. I (almost) always do that on my mods when putting them back together.
As for the stock light.
K40M stock emitter amps
4,86 startup
4,77 10 sec
4,71 30 sec
4,66 1 min (Before stepdown)
4,18 1 min 10 sec (After STEPDOWN)
4,16 2 min
4,14 2 min 30 sec
4,12 3 min 30 sec
4,11 4 min 30 sec
4,10 5 min
So what some might think is heat sag, is a combination of driver giving less amps to the emitter over time + stepdown + natural heat sag.
Ive mentioned how lumen drops in my comparison thread with other lights. Pictures and beam shots there too in case people have not seen.
"K40M drops about 210 lumen at 1 minute 10 seconds. From 1 minute 10 seconds and to 5 minutes it drops another 80 lumen.
....
I put some protected NCR18650BD at 3,6V in both lights. K40M showed 2856 lumen (basically the same as with fresh batteries)"
Ill probably post mod results and more data in your mod thread once my light is done and properly tested. My light is currently in pieces. Not sure what day Ill put it together. (yes, the small sealed screws at the driver compartment were a PITA. Supbeam X40 did not have sealed screws.)
which mods are you planning?
finally finished my review;;; please see here:
My tailswitch board was not attached to the tailcap. Is that normal?
Mine was like yours too. So I guess so?
that’s correct
it is just press fit
Cons:
No cutout in the tailcap for switch access
Ratcheting ring
Standby incorrectly spelled as “stand by”
Tint seems cooler than the ones in the mm15
Mouse Out: AceBeam K40M
Mouse Over: NW SRK (good one from CNQG)
80 meters to the building.
Mouse Out: AceBeam K40M
Mouse Over: NW SRK (good one from CNQG)
