January 2026

Switch protector for Maeerxu EDC Titanium Alloy Mini Flashlight R7

A little flashlight is one of the most useful tools to have in your pocket. I use it more often than e.g a swiss army knife. I find that such a flashlight needs to have an AAA battery and not a built-in rechargeable battery. Anything with a rechargeable battery is probably dead and expired in 5 years rendering such a flashlight useless after only a few years of use. AAA batteries are easy to find and a well built flashlight can last forever.

Many of the mini flashlights are made of aluminium. Aluminium does not feel good and it's too soft. It wears out easily. Titanium is the ideal material. It's very bio-compatible, light and hard.

I discovered recently a chinese flashlight called "Maeerxu EDC Titanium Alloy Mini Flashlight R7". You can get it at https://www.maeerxu.net/product/r7-titanium-mini-flashlight/. I love it. The electronic booster circuit inside the head of this flashlight works down to 0.9V allowing for a very long battery life. Old batteries that fail in other flashlights will make this one still shine bright.

Maeerxu EDC Titanium Alloy Mini Flashlight R7

The flashlight has 3 modes: bright (high), dimmed (low), flashing (strobe). I don't know what the flashing is good for but full on bright and dimmed are useful. Many mini flashlights with different modes are difficult to use because the switches don't work reliably. As switches wear out they start to bounce and this results often in the flashlight ending up in the wrong mode. The "Maeerxu EDC Titanium Alloy Mini Flashlight R7" is different. The flashlight has an electronic tail switch. The switch is only a push-button and it is made into a properly de-bounced on/off switch with the help of some electronics. One click brings the flashlight up in "full bright" mode. Two clicks goes to dimmed and 3 clicks goes to flashing. This works reliably and you never end up accidently in the wrong mode. The build quality of this flashlight is excellent.

The only problem that this flashlight has is the unprotected tail switch. If you have multiple things in your pocket then the flashlight will come on by itself because something hits the tail switch somehow.

The fix for this is to make the tail switch a bit retracted inside a kind of a "washer". The added benefit of this is that the flashlight can now stand on it's tail end and you can illuminate the whole room by shining the light against the ceiling. You can also fold a white sheet of paper into a kind of a tent and put the flashlight standing on it's tail end inside. This gives a candle effect.

I designed a switch protector for this flashlight and you can download the STL-file and 3d-print this washer. The best way to install this washer is to glue it on with Gorilla Glue Clear. Note the word clear. Normal Gorilla Glue is a white foamy glue. Apply a tiny amount of glue evenly with a toothpick and make sure no glue gets into the switch. Gorilla Glue Clear dries hard and bonds to metal but needs about 2 days of drying for this kind of application. Another way to install the washer is to use a section of a large shrink wrap insulation tube.

Maeerxu Titanium Mini Flashlight with 3d printed switch protector

switch protector, a kind of a washer to add to end of the flashlight

Using the flashlight as a candle. This is excellent if you want to take notes or write a letter. The paper "tent" acts as a diffuser.

Head of the flashlight with circuit board. This circuit works from 1.6V down to 0.9V.

Product images with specifications from maeerxu:

Maeerxu Titanium Mini Flashlight version R7. XPG2 wick means CREE XP-G2 LED

Modes: The flashlight reverts at the next button "on" press to hight mode if you wait more than 10s since the last button press. The tail switch is just a push button and contains electronics to make into an on/off switch.

I don't really need a waterproof or water resistant flashlight but Maeerxu advertises this flashlight as IPX6 water resistant. It has seals around the threads for the battery compartment which makes it look solid and well sealed. It seems impressive but watch out: The tail switch has no seal at all. There are two layers of circuit boards below the switch and I believe that any water drop that gets in via the switch will have a hard time to evaporate. It could stay there for a long time and cause corrosion on the circuit boards. I think you need to protect the switch somehow if you use this flashlight in a wet environment. You could pull some rubber membrane (e.g a rubber finger protector) over the switch while you use it around water.

References

STL for 3d-printing the switch protector: daddyflashlight003.stl
The dimensions are: outer diameter 16mm, inner hole diameter: 9.4mm, height 2.5mm
Freecad flashlight washer design file: daddyflashlight003.fcstd
A good stl file viewer: https://www.viewstl.com
Web site where the flashlight is available: https://www.maeerxu.net/