After developing the online game and server, plus being now able to send the game data to the ESP32 (the brain of the chessboard), the next step is to design and build the physical chessboard.

After many brainstorming sessions, we settled for this design of the chessboard:

Key Elements of the Design:

• Sphere : 20 cm diameter, tilted at approximately 25°, will be 3d printed.
• Chess Piece : 60 mm in height, held in place with magnets, will also be 3d printed.
• Rail : The rail will be made of mutiple layer of laser cutted wood/acrylic.
• Motors and Actuators:
  • 3 stepper motors (sphere rotation, capture zone rotation, cart movement on the rail).
  • 1 linear actuator.
  • 2 servos (one for linear actuator rotation, one for the gripper).
• User Interface: A small screen for displaying information and configuring the chessboard.

How It Works:

Each square on the spherical chessboard is accessible through two movements (if we visualize the sphere as a flat plane) : rotating the sphere move through the files and moving along the circular rail move trought the ranks . 

This is how a move should be executed :

1. Moving to the targeted piece: The cart moves along the rail and/or the sphere rotates to align the gripper actuator with the targeted piece position.
2. Taking the Piece: The linear actuator extends, the gripper close to grab the chess piece then the actuator retract.
3. Moving to the target square: The cart moves along the rail and/or the sphere rotates to align the gripper with the desired position.
4. Releasing the Piece: The linear actuator extends, and the gripper open toreleases the piece.

And this is how capture should be handled  :

The cart moves to a fixed position above the capture zone (a rotating circle at the bottom). The linear actuator rotates, extends, and places the piece in the capture zone. The zone then rotates to make space for the next to be captured piece.