A speed-adjustable mini fan made from an empty 36g Luofu glue stick. The old method melts through the screw post inside the stick; a heated knife cuts two opposite notches in the head of the stick; a heated wire opens a big hole in the cap, then flip it and cut two more notches. Take two 16340 Li-ion cells (UltraFire marked 3200mAh) and the U3 Pro-edition spot welder gifted by AWithZ official, power on and set auto mode (the body also doubles as a power bank); series: place one + up and one − up, lay the nickel strip on and spot weld — very solid; flip over, wrap a short piece of nickel strip around the ends of two wires and weld them to the other face of the cells, red + black −. Without a spot welder you can use a conductive plate and wrap the wires with electrical tape. Fan motor + switch, plus a low-value potentiometer for speed: bend one pin of the potentiometer to the motor’s other wire; red wire to the switch, black wire to the potentiometer’s middle pin; hot glue holds the wires; fold the side-by-side pack upright into the stick, drop in the motor, cap it; hot glue holds the potentiometer and switch, tape wraps the wires, fit the blades. Done, the potentiometer sets the speed; to charge you take it apart — only one cell at a time. Top-liked comment (45) warns ‘who taught you to spot weld like that? one cell going off because you didn’t press down and you’ll behave’ (creator liked it); suggestions: just wire it with a soldering iron, add a TP4056 charger, use a test tube for the shell, swap in a hobby-grade motor.