After losing the charging cases for two sets of Redmi Airdots earbuds, Chinmay Shalawadi decided to design and 3D print his own DIY case for them.
The first step was to measure the earbuds, which was a bit of a challenge due to their complex shape and because the pogo pin connectors need to be aligned precisely. The position of the right earbud was in fact off, so a second version had to be manufactured, then a third when it found the buds were too deep to remove. It’s a testament to the magic of 3D printing, as this certainly took some extra time for these iterations, but not a huge expense.
For charging connections, pogo pins are sandwiched between magnets that hold the earbuds, which are held together in tiny 3D-printed inserts. These magnets and pins can be sourced from other devices, but after attempting such an operation, Shalawadi eventually ordered new pins to take care of this job.
Electronics-wise, the unit uses an old Nokia smartphone battery, along with a TP4056 charging board and a step-up circuit to produce 5V. Cleverly, the indicator LED outputs are run to a (non-addressable) RGB LED, so this could be positioned to shine through the top.
It’s a handy build, and as of the video’s recording, it has been in use for a couple weeks without even having to recharge! Print files are available on Thingiverse if you’d like to recreate the project and more info is found in Shalawadi's write-up.