Mechanical Servo Motor Clock

Date of publication: 11-09-2024 Update date: 10-04-2026 🕒 6 min read

Does clock construction always require masterful precision? Discover how to build a functional and eye-catching clock using 3D-printed elements and Arduino..

The Hardware you will need:

1x Arduino UNO
2x PCA9685 PWM Servo Driver
28x 9G Micro Servo Motors
3D-Printer
5V External Power Supply

7-digit Display with Servo Motors Controlled by Arduino

Can You Make 3D Printed Mechanical Clock?

Step 1:

Download the STL files here >LINK<. Use your 3D printer or a 3D printing service to manufacture all the necessary components. This may take some time. :)Be sure to print the caps in a different colour than the rest of the project, to ensure that the digits can be distinguished from the rest.

Step 2:

Assemble the components for the digits by mounting the 28 Micro Servo motors onto each base plate, as shown in the picture to the right..

Step 3:

Mount the 28 single 3D-printed segments onto each one of the Servo Motors.

Ensure that the segments are aligned as shown in the picture below.

Step 4:

Place the 28 differently colored 'shoes' onto the 28 segments. To improve the quality of the shoes, you may consider 3D-printing them at a higher quality. The print quality of the ones used in this project were 0.2 mm.

Step 5:

Assemble the frame of the mechanical servo clock. The parts can be clipped together, but for improved stability, you can use some bolts and nuts.

Step 6:

Insert the individual digits into the outer frame, paying attention to the top and bottom of the digits. Ensure that all four digits are mounted in the same direction.

Step 7:

Connect the 28 micro servo motors to the two PCA9685 Drivers, as shown in the schematic image below. You may need to zoom in to read the connection numbers (0-15).

To identify the servo motors, refer to the second image where the arrangement is shown.

Step 8:

Solder a connection from the A0 bridge to the second PCA9685 servo driver. Then, connect both drivers together as shown in the schematic image above.

Step 9:

Connect the PCA9685 driver to the Arduino using an I2C connection. SCL should be connected to Pin A5, and SDA should be connected to Pin A4 of the Arduino UNO. Also, connect the driver to the GND and 5V pins of the Arduino.

Step 10:

Add a external power supply to ensure sufficient power for the 28 servo motors. Connect the external power supply to the Arduino by establishing a connection between GND and connecting the output voltage to the VIN Pin of the Arduino.

Step 11:

Connect your Arduino to your PC and open the Arduino IDE. Download the Code and upload it to the Arduino UNO.Here is the link to the Code: >>LINK<<

Disconnect the Arduino from the PC and power it only from the external power supply. Enjoy!

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