** A digital clock with vertical bars. **

• The weight of a bar itself moves the neighboring bar when carry up.
• Only one servo motor
• Reduction gears make it possible to raise neighboring bar by the dropping lighter bar (lever principle)
• Easy to adjust the time

Caution : To be honest, making this clock is not recommended because it is very loud when bar drops. The durability of this clock is questionable because impulsive force of dropping bar will damage somewhere. To print the clock with supplied STL files, you need large 3D printer (300x300mm build table).

To design the gears, I used "Precision Gears" addon for Blender, https://makertales.gumroad.com/l/PrecisionGears