SmallKat Is an Open Source, 3D-Printed Kitty Robot

Earlier this year, roboticist Kevin Harrington and a group of students from the Worcester Polytechnic Institute unveiled SmallKat, a dynamics oriented quadruped robotic cat designed for testing different walking gaits and as an educational platform. The robot came in three different sizes — micro, small and XL, all outfitted with nearly the same hardware, including 16 MG92b micro servos, three switch mode BECs, a Bosch Sensortec BNO055 9-axis IMU, Turnigy 1000mAh battery, and an ESP32 module.

A few weeks ago, Harrrington and his team announced a revision of the SmallKat robotic platform, essentially combining the original and the last version, as the previous model was deemed too big and heavy for their needs. The latest iteration has been streamlined and features longer legs with a slightly larger body, as well as utilizing M3 hardware for more accessible procurement and assembly. They also added optional encoders for additional feedback, provided improved calibration, and gave the robotic cat better aesthetics.

“This version of the cat has more parts than the original however the assembly process is significantly easier, and it is more robust. Additionally, replacing servos and other parts takes much less time. The next step will be wiring and running this version through some tests with walking and fixing a few small design errors with tolerances. This version is getting closer to what we hope a final and commercial product would like. Still a lot of work and testing to go before we get to that point.”

All of the updates and a detailed walkthrough on building the SmallCat, including schematics and files, can be found on Harrington’s project page. For those who might not have access to a 3D printer, he is selling the SmallKat on Tindie as a kit ($500 and up) or as a fully assembled and calibrated robot.