AA/14500 zoomie 3-mode to single mode mod

Two years ago (Nov 2016) I bought these AA zoomies an aliexpress:
Skywolfeye E526 ($2.06)
Warsun Penlight ($2.40)

They both suck unmodded, the switch springs are way too hard and light output is low.
They also have 3 modes including strobe.

Some measurements:
Skywolfeye E526:
emitter pcb 11,4mm
driver: 12mm
plastic reflector 14.2mm
cap switch housing diameter: 10.9mm
cap current (high mode) 130mA

Warsun Penlight:
driver: 15mm
cap current: 130mA

Older AA zoomie and Warsun Penlight (the latter measuring 23x93mm)

For comparison, an unmodded AA single-mode zoomie (from this thread Review: #3 Noname $3.60 XPE-Q5 single AA/14500 zoomie) draws ~1A.

LEDs/reflectors. Left Skywolfeye, Right Warsun.

Skywolfeye E526 LED closeup, damaged from drilling through reflector (2.5mm drill bit).

First, I attempted to mod the switch of the Skywolfeye light.

I should have pushed out the switch assembly, instead I tried to in from the spring side, using a soldering iron to dig through the plastic cover.
IDK if you can guess it, but the plastic parts provide a locking mechanism which lowers the smaller metal ring, which connects directly to the spring, onto the larger ring which connects to the unanodized inside of the tailcap. The plastic cover fits on the rest of the assembly and presses the ‘wings’ of the larger ring onto the tailcap, so destroying it should be avoided.

In order to adjust the springs hardness, I wrapped the smaller part in water-soaked toilet paper (both inside and out) and exposed the larger, shorter part to an alcohol flame. Alcohol is preferable here since it doesn’t produce soot. The flame should provide ~800°C at its apex, about half that directly above the wick. I went with 2x ~10 seconds exposure in the center of the flame.

Spring steel normally has a temper range of ~200-400°C. The process is both time and temperature dependant, with temperature having a much more significant effect.
The goal here is to reduce hardness, but not so much that plastic deformation becomes easily possible.
Theoretically higher tempers can reduce spring life due to a phenomenon called blue brittleness which effects non-Si-alloyed steels at temperatures around 300°C.
While the spring was succesfully softened, I was not able to use it.

Next I attempted to mod the driver. I tried to remove the SMD IC responsible for mode selection after looking at single mode and 3-mode boost drivers on fasttech. I choose the wrong part, the light would still draw current but not put out any light.

Then I attempted to ghetto reflow the IC over the same alcohol flame from earlier, resulting in the destruction of the whole driver. I tried to ballpark the temperatures above the flame using a thermocouple (stock TC of UNI-T UT202), but still the method was way too crude. Using a piece of aluminum or similar as a heat spreader might have worked better.

So I searched for ‘flashlight boost driver analysis’ on duckduckgo and found this page:

(there’s a backup on archive.is if that one stops working)
I attempted something similar on the Warsun driver as the layouts are very comparable, except I didn’t even have to use a wire since the outer ring on this driver is thick enough to bridge the connection with solder alone.

(pic shows unmodded state)
This removed mode selection and increased draw current to 1A.

Lastly I disassembled the Warsun tailcap in hopes of using the modded spring.

I pushed a fitting dowel through the tailcap using a vise, this successfully removed the switch assembly but also mangled the rubber cover. The switch assembly differs from the one found in the Skywolfeye tailcap.
Upon reassembly the switch would no longer work as the damaged rubber cover somehow catch and jam the whole thing, the slightly longer cover from the Skywolfeye E526 also didn’t work. So now I have to use the light without a switch cover.

Later on I used the driver mod on an older AA zomie, similar to the ones in the linked thread but with a black reflector placeholder. The mod worked as before and increased current from 100mA to 1.4A. As the driver layout was slightly different I had to use a small wire to connect IC pin to driver rim.

Perseverance finds a way! Although you had your shortcomings, detailed methodology helps others; the 8133A hack that you linked could have saved one of my own SkyWolfEye.

I find that sometimes I purchase 2 units of unknown construction, one for dismantling knowledge (that I can sacrifice), the second to better rebuild.

Those tail switches are frail. Best way is removing the metal clip with a hook tool and some mini long nose. Naturally, the clip gets distorted, but I can re-work it on the bench. As for reflowing an IC on driver board, use an electric coffee pot heater (those from the 60’s early 70’s) with an aluminium plate over the element. A 1500 Watt AC light dimmer as the controller. Bare heat over a flame can’t be precise.

I don’t bother changing driver components though. Much easier to get a Nanjg AK-47A with Guppy DRV from MTN Electronics and fit to the host. Had a good outcome on a SkyWolfEye TLY-327. Will be attempting a doubled walled rear clicky on a Duracell host (driver in the tail as no room in the head). Usually, have to change MCPCB as well as the reflector. All components from MTN as less prone to my interpretation of data characteristics error (i.e. my knowledge is enough to investigate but not always to design).

Reminds me of my darkest modding days back when cheap flashlights were always junk. Nowadays I’m lazy enough to start mods with better hosts than the Skywolfeyes and Warsuns (although I still want to mod one of those Skywolfeye AAA zoomies).

Thanks for the write-up.

I found the plastic cover much harder to remove. The clip/ring wasn’t a problem.

At 17mm, the AK47a won’t fit. 12mm/15mm driver PCBs respectively.