Mechanical 7-segment digital clock

Mechanical 7-segment digital clock with 23 segments, controlled by only one RC servo motor. Not only all segments but also carries between digits are mechanically resolved.

- display size (size of the front panel) : 23cm x 10cm
- digit size : 8 x 4cm (the area of center line of each digit)

It consists of 54 types, 115 parts printable with common 3D printers. You also need
- 1 RC servo motor (normal, full size servo. I used Sanwa SRM-102Z)
- 1 micro:bit and 5V power supply (break-out board, etc.)
- 7 rubber bands
- 19 M3 bolts
- paint (ex. white paint for black 3D printer material)

Necessary tools
- sand paper or file for deburring
- soldering iron for welding plastic
- M3 Screw tap (if you do not use tapping screw)
- Silicone grease or spray for lubrication

Tips
- all parts can be printed out without supports.
- for smooth operation, deburring and lubrication is very important.
- A few cases of breaking rothook.stl (ratchet hook) during the daily