(a new day, a new flashlight brand :-) )
This flashlight caught my attention in the new arrivals section at dx a few weeks ago,
The Cofly KX-A036, a 1x 18650 (5 mode) zoomie, for 'complete' specs, see the dx-site.
Cheap ($11.36) and good looking, and finally a zoomie that has a sliding part that is not unnecessary wide for the tiny lens that is usually in it (exception: Uniquefire T20: big lens for its diameter). Sometimes those zoomies even have impressive cooling fins on the slider which is pointless, that is hardly where the heat goes.
I bought it and it arrived yesterday. It was a bit heftier than I thought, but I think the size is nice for what it is. A comparison to some other 18650 zoomies:
From left to right: Uniquefire UF-T20, Cofly KX-A036, brandless Sipik sk98 clone, Ultrafire ZB-something-cheapy-can't-remember, and again the Cofly KX-A036.The build quality looks much better than the sk98 clone and the flimsy Ultrafire, it feels really nice and has good modding options, but later about that.
First some thoughts on the optics. It shares the optical lay-out with the sk98 clone, the Ultrafire, and lots of other cheap zoomies: a lens with a focal length that is a bit too long to my taste for a zoom flashlight, which is a pity (exeptions: sk68, Uniquefire UF-T20, and just a handful others). Explanation:
A rough sketch, but actually drawn to scale, one square is 0.5 x0.5 cm. (the lenses are drawn a bit too thick actually, but that does not affect the point being made)
The Sipik sk68-and-clones have a very curved fat aspheric lens that gets the die projected in focus when at a very short distance from the led, it catches a wide angle of the light, even when zoomed in (same story for the Uniquefire UF T20). The Cofly/sk98/UltrafireZB have a flatter lens that achieves the right focus at a longer distance from the led, and therefore catches a smaller portion of the light (more light loss, less coming OTF). The throw (spot intensity) is actually not affected by the weaker lens, but the hotspot is smaller than it would have been with a fatter lens (but not brighter!).
I will try to find and fit a shorter focus lens for this flashlight to improve the performance.
The tail current that I measured with a fully charged Panasonic CGR18650CG is 2.86A, not bad for a stock light that is so cheap. Ceiling bounce lumen estimate: zoomed out 490 lumen, zoomed in 195 lumen (do not trust these numbers to be dead accurate, ceiling bounce measurements of zoomies I found sometimes give strange readings compared to reflector lights) . Projecting the hotspot next to a XRE sk68 clone (on a 14500 IMR 1.5A tail current) shows that the throw is less, but not extemely far off, which is nice for a XM-L zoomie:
The led die, as seen in real life (does not show well on picture), looks strangely rough and damaged, perhaps not the best batch of XM-L's is used for this light.
Tear down:
Inside the slider, looking at the back of the lens. Nice thin aluminium retaining ring: the lens is almost fully used.
Plastic led-board retaining ring, hard to remove! XM-L on 16mm board. Ample thermal paste under the board, nice.
A good solid pill with 17mm driver, not hollow: there is a whopping 3mm of aluminium under the led board! Lots of space inside the pill for any double/triple/quadruple whatever 17mm board. Big spring under the driver: the light accepts any length of 18650 cell, protected or unprotected, the thickest I have (with extra wrap for the protection board) are a tight fit.
I am not an expert, but this looks like a simple and effective direct drive board with PWM-controller. Nice touch: I can't detect any PWM on lower modes by waving the light frantically before my eyes: PWM frequency must be very high, as high as qlite (can't see that one either).
The body part where the pill screws in is thin, just as with the Sipik sk68, I used to worry about the heat not getting away from the pill, but in the sk68 is just appears not to be a problem, and I think this light is no different, it will do the job just fine. Nice amount of trapezoid anodised threading at the tail, well lubed, this can handle longterm use, and the light can be locked out. I hoped to have a look in the switch area too, but I found it impossible to remove the alu ring (I will try later with heat, but for now I will leave it at that). 14mm boot cap, the light I received hardly tailstands but others may be better, mine needs a lower bootcap.
Concluding: I like the looks and feel of this light very much and it seems well made, for $11.36 shipped IMO the price is excellent!
Next is modding it, I'll keep you informed :-)