DIY high-power flashlight tutorial: three 18650 cells and an e-bike headlight for under ¥20

Ep. 41 | Home speakers built from car speakers — surprisingly good? Turning car audio into a home stereo that sounds this good

Ep. 45 | An adjustable power supply with high-end features at rock-bottom cost? Building a portable, precise, digitally controlled adjustable supply from simple materials at the lowest cost — the result is a surprise

Universal magnetic base build guide — the step-by-step build guide for the universal magnetic base is here

Ep. 36 | A Bluetooth speaker bought for under ¥1 sounds amazing after the mod! A junkyard speaker turned into a wireless Bluetooth speaker — the result is a real surprise

I built a ‘New Year atmosphere machine’? If your village had a voice-controlled remote firecracker toy like this, would you stay home a few more days over the New Year

Ep. 43 | A homemade electric grass trimmer? A simple electric trimmer built at home from scrap, and it works really well

DIY flashlight — 3×18650 + e-bike LED, under ¥20

DIY an ultra-long-runtime seven-color night light? For the last science maker class of the term, I hand-built an ultra-long-runtime seven-color night light as a gift for my students

Universal magnetic base — step-by-step

Ep. 61 | Last time a friend asked for one made from 18650s — today we build it; the full build is in the video, please watch patiently

Build your own portable knife-sharpening gadget that every home needs? Kitchen knife gone blunt? Build a portable belt grinder on the cheap and never worry about a dull knife again

Building a lithium-powered electronic magnifier to hunt for gold inside chips

The batteries I planted are ripe — picking a few to make a power bank