OK, today's mod - cheap zoomie from Ali, link here to old listing, paid $7.14 w/free shipping
, back in June of 2020. Typical fake XHP50 as advertised. This one turned out to be not so bad for modding:
- decent switch feel
- decent switch LED's - 2 green, 2 red, nice window on the switch
- enough room to piggyback in a driver
- lens, though plastic, looks decent (generally I've seen plastic perform better than glass in aspherics)
Plan is to make it a decent thrower running Anduril 2. Here's the basic pieces, with the replacement driver mounted:

Stripped all components off the original PCB's, both driver circuit and USB charging circuit. Mounted it vertically on the short vertical board because it had the most open space, and could solder it directly to a ground plane. I notched the new driver with a hand file so it sits a little better to the stock vertical board. The rest was adding a grnd wire, batt+ wire (not shown on the other side), and the switch and LED wires. I traced things out to find the switch, green LED's, and red LED's pads. The switch, green and red LED's are all on the backside of the large vertical board (not shown). The switch wire is white, green LED is green wire, and red LED is the blue wire, all 30 AWG. It's actually a pretty clean piggyback setup.
The red LED's won't currently be used - they are wired to MCU pin #7, but just don't have support in Anduril 2 for a second color LED for the ATTiny85:


Here's the underside showing the batt+ and batt- connection to the driver, 28 AWG for batt+ (not for powering the main LED), and I believe 26 or 24 AWG for the batt- which feeds the driver and output circuit:

Replaced the stock spring with a "blue" spring of similar size and relative stiffness:

Went with OSRAM W1 3030 for best throw, moderate amps. The pill surface was actually in pretty good shape, better than many "brand" lights I've worked on. Did some light sanding to get it super smooth, MX-4 applied. The MCPCB will be secured down by re-using the stock black plastic press fit retainer - works for me.


Since I did away with the charging, thought I'd seal up the charging hole with JB weld. Came out pretty good for me:

Fully assembled, used 26 AWG long LED wires, same length as stock actually. because screwing the pill into the base results in twisting the wires, so the extra length comes in handy for that, plus I need to add resistance for the W1. No spring bypasses - driver spring is high performance ("blue"), and tail spring is thick and stocky.

With the 5000 mAh Wurkkos cell used in testing. The tailcap doesn't fit well to the tube when under pressure of a loaded battery. Stiff springs make it somewhat difficult but the threading is a poor fit. I can only catch the last 1-2 threads, but at least it tightens up.

Played around to get it centered well, actually didn't have to do much. Maybe cant see it, but the black plastic retaining ring is in this shot. Used a high quality lens cleaner on the plastic aspheric, and it came out pretty nice

Other Details
- head diameter is 42 mm
- plastic lens outer diam: 38 mm
- plastic lens dome diam: 30.4 mm
- used a 11K resistor for the 2 green switch LED's (primary)
- used a 6.2K resistor for the 2 red switch LED's
The Results
Very happy how the switch green LED's came out with Anduril 2. The low setting is easily visible and the high setting is not too bright, but bright enough.
- measured roughly 6 amps at the tail, but figuring the tail cap/spring will reduce that a bit
-
700 lumens at start (maukka cal factor)
- throw: 182 kcd, 853 meters
- when zoomed out, the flood zone is very wide due to the lens' close proximity to the LED when fully retracted.
This came out better then expected. I'm not seeing any angry blue in the beam, though probably not running it more than 30 secs at a time.
Again, cheap plastic aspheric lenses do the job. There are many similar cheap (under $10) zoomies like this in slightly different styles. I have another one that I didn't even open up yet, but it does have a better fitting tailcap and identical size aspheric lens. It's always a gamble though when buying one of these to mod - never know what to expect inside.