When it is running, this quadruped trots and walks around indoors, holds its chassis level on an inclined cushion using IMU data, and runs an idle breathing animation. A puppet mode matches the chassis orientation to the tilt of a handheld smartphone. The head carries a rectangular display with customizable blue digital eyes, which is a nice touch of character.
PrintedRobotics built it around an ESP32 S3 with a PCA9685 servo driver, an MPU6050 IMU, and a voltage sensor board. Two 15A adjustable buck converters feed the legs, one per pair, while a separate 5V 3A converter keeps the ESP32 isolated. Twelve DS3218 high-torque servos drive the twelve degrees of freedom, down from eighteen on the earlier hexapod this design came from. The frame, leg linkages, and head casing are printed in red, white, and black, held together by roughly a hundred M3x8 screws, four M4x30 screws, and twelve ball bearings. A 3S LiPo between 3000mAh and 6000mAh powers it, and tests show over 20 minutes of runtime.
Two details stand out to me. Sacrificial printed clips snap during impacts to protect the servo motors, which seems a smart way to make crashes cheap. Servos and the controller run on independent converters to avoid brownouts without custom PCBs, and a Wago connector plus lever-nut splices keep wiring simple.
The open question: both antennas are cosmetic only right now, since an antenna plug burned a board and a regular ESP32 S3 was fitted instead, and the benefit of running two antennas is debatable anyway. The current inverse kinematics walking looks mechanical; reinforcement learning training is planned in the hope of more fluid motion. ESP32 scripts and an Android controller apk are on GitHub, with CAD, print files, and a wiring diagram shared online. At around 200 USD, that seems a solid deal.
Project by PrintedRobotics. Watch it on their YouTube channel: