DIY Handheld Fan

Info

- Depending on the used cell this fan offers up many hours of continued usage.
- Has a flat bottom to put it upright on a table.
- Angled at 20° so your fingers are not getting cut off quite as easily and it can be used as a desk fan.
- Short circuit, overcharge and overdischarge protection.

Apologies for no photos of the finished fan. I did build one but that was years ago and I couldn't find any photos.

Parts List

- 19x15mm (cutout dimensions) Toy DC Motor (up to or around 3-6V)
- 2mm-Shaft Propeller (can be bought in a kit with the toy motors or printed via another 3D model)
- 18650 Li-ion Cell with tabs welded on the poles
- TC-4056 Li-ion Charge Controller
- 15x7mm (cutout dimensions) Mini SPDT Slide Switch
- USB C breakout board (optional)
- Wires (0.75mm² / 21 AWG recommended)
- Soldering iron, solder, etc.

Assembly

Refer to this Schematic when soldering parts together. (Note: it was made with outdated parts numbers but is still usable.)

1. Solder wires to the Li-ion cell.
   It's recommended to use a cell that already has tabs welded to it to reduce thermal stress.

2. Glue the Li-ion cell into the base piece so it doesn't shake around later.
   I used hot glue but anything that works on plastic, sets quickly, and is viscous enough, should work.

3. Solder wires to the switch (common/center and ON position pins) and glue it into the cutout on the base piece, ensuring the ON and OFF positions are in the correct orientation.

4. Insert and glue both the USB breakout board and the motor to the two top pieces.

5. Solder one of the motor's poles to the switch's ON position.

6. Glue the TC-4056 charge controller somewhere inside either the base or top piece. Make sure it's positioned so you can still see the charge status LEDs shining through the cracks somewhere, to be able to tell when the charge cycle is finished. (If you're printing in see-through / white with thin enough walls, the LEDs should just be able to shine through the material.)

7. Solder everything together like shown in the schematic, making sure no exposed wires can short out while handling the fan.
   Before hooking up the two wires to the Li-ion charge controller's outputs, test both polarities to figure out which way the motor needs to spin, then solder the wires in that configuration.

8. Plug in your charger and test if everything works as it should.

9. Glue all three parts together like shown in the “fully assembled” file.

Note: if the outputs of the Li-ion charge control board accidentally got shorted, it might need a short burst from the charger to reset and output any power again.