SmallKat: A 3D-Printed Robotic Cat for Research and Education

Roboticist Kevin Harrington and a team of students from the Worcester Polytechnic Institute have designed a “dynamics oriented quadruped” in the form of SmallKat — a robotic cat for research and educational purposes. The 3D-printed (PLA) cat was designed as a robotic project platform to test different gaits and sensors.

“The intention of the platform was to make a fully open source dynamics quadruped for the education/research and high-end toy markets. Using hobby servos and common electronics allows the overall price point to remain very low in comparison to its competitors.”

SmallKat comes in three different sizes — micro, small, and XL, but they all feature similar hardware configurations. Under the hood, the SmallKat is equipped with 16 MG92b micro servos, three switch mode BECs, a Bosch Sensortec BNO055 9-axis IMU, Turnigy 1000mAh battery, and an ESP32 module, which sends data to a nearby PC for all the heavy data crunching. What’s interesting is that the robot’s kinematics and walking/gait controllers can all be switched-out on the fly without needing to restart the platform to do so.

As mentioned earlier, all three versions of SmallKat include most of the same hardware; however, the larger, more advanced robotic cat uses an onboard Raspberry Pi rather than a PC for data processing. Future revisions will employ a custom STM32 board, which will make the robotic cat more costly and will require the use of a Git server to run new code in development.

All versions of the SmallKat are controlled with code created with Bowler Studio, which allows you to use live 3D models to input motion trajectories to control the cat. Those interested in a more detailed walkthrough on the SmallKat build process can head to Harrington’s page, as well as his GitHub page for the SmallKat framework.