“I enjoy designing and building interesting clocks and am always looking at unique ways to display the time. This clock uses 4 vertical slides that contain the numbers. Four stepper motors position the slides so that correct time is shown in the display area of the clock.
The steppers are controlled using an Arduino Uno with a CNC Shield. It uses an Adafruit PCF8523 RTC board to keep the time. The case and mechanical aspects are all 3D printed and the slides displaying the numbers are made of wood with laser engraved numbers.
I used 3d printed rack and pinion gears mounted on the back of the wood slides to move the slides up and down. The rack and pinion system was derived from this linear motion device made by Trigubovich on Thingiverse.
Cryptic Version
I made two versions one using normal numerals and a cryptic version based up cfb70’s Cryptic Calendar Instructable.
Supplies:
Ardunio Uno
CNC Motor Shield
A4988 Motor Driver (qty 4)
Adafruit PCF8523 RTC
Steppers 28BYJ 5V (qty 4)
Power Connector - Barrel type
Pushbutton Switch (qty 2)
Power Supply 12v
Misc 3mm bolts and nuts
2mm screws for RTC board (qty 2)
1.5 board feet of 4/4 hardwood (I used Birdseye Maple)”