I own a Miniware ES120 electronic screwdriver. It’s one of the last devices in my household that still has a microUSB connector which is pretty annoying. So I modded it to use USB-C. The mod is quite simple, you need a small PCB with the USB-C port, a new 3d printed end cap that sticks out a little and you need to solder the connections to the original PCB. In the end everything looks pretty neat and works really well.

Here’s a little build guide.

BOM

Part	Count	Schema Ref	Description	Mouser	LCSC
GCT USB4120-03-C	1	J1	USB-C port	640-USB4120-03-C	C3445864
5.1 kOhm Resistor	2	R1,R2	0603/1608	667-ERJ-3EKF5101V	C2907114

You can get the parts on Mouser or LCSC. Get the PCBs from Aisler or JLCPCB. The 3D printed end cap can be ordered at JLC3D. They can even assemble everything for you if the parts are too small for your taste and you don’t want to solder it yourself.

The endcap can also be 3D printed at home, at any other 3D printing service or at your local hackspace.

Additional parts

To connect the breakout board to the PCB you will need some enameled wire or single core cable strand.

PCB

The gerber files are zipped in the production folder. Upload them to the PCB fab and make sure the PCB has a thickness of only 1mm. There is really not much space in the housing.

Endcap

You can find the 3D model in the repository or on Printables.

If you want to print it yourself, I’d recommend using a 0.25mm nozzle. I printed it in Prusament PETG Prusa Galaxy Black and it came out pretty nice.

Integration

1. Unscrew the end piece of the screwdriver
2. Unscrew display with Torx T3
3. Remove display cover
4. Remove PCB
5. Desolder microUSB port
6. Solder wires from PCB to USB-C adapter
7. Insert PCB back into the case
8. Put display cover back on
9. Put adapter PCB into endcap
10. Put endcap into the slots so it fits snug
11. Screw on the metal end piece
12. Put the display screw back in
13. Profit!

Try to charge the screwdriver and connect it to a PC to check if power and data lines work again.