Anand D
Author
In an impressive display of rapid prototyping and engineering grit, creator Kayden Knapik successfully designed, built, and programmed a fully 3D-printed bipedal robot named Stompy in just 3 days. Utilizing the Bambu Lab P2S 3D printer, Knapik fabricated the robot's structure from scratch. The mechanical design features six degrees of freedom three per leg powered by six Robstride 02 motors, 17 Nm of torque each to ensure the robot could handle locomotion.
To achieve movement, the project skipped traditional manual trajectory programming in favor of reinforcement learning. By running thousands of simulations in parallel, Knapik trained a walking policy that was later deployed to the robot’s Jetson Orin Nano processor. The initial training revealed a common pitfall: the robot default-walked like a quadruped with inverted knees. By modifying the foot geometry and re-training the policy to encourage forward-bending knees, the robot finally achieved a more natural, human-like gait.
By the end of the three-day build period, Stompy proved capable of walking on various surfaces, including concrete and uneven terrain, and even demonstrated balance recovery when pushed. With a total build cost of approximately $1,000, this project serves as a compelling open-source-focused starting point for hobbyists interested in building their own humanoid robots. Future iterations aim to improve the platform's stability and capabilities, with project files and code currently being made available to the community.
