A small walking biped built to be simple: each leg is a printed four-bar linkage driven by two hobby servos at the hip, one for the thigh and one that sets the knee through the linkage so the foot stays level. A fifth servo turns the leg pair under a weighted top mass, which is how it shifts weight and steers. An ESP32 runs the gait from a joystick remote over ESP-NOW and reads a SparkFun BNO08x IMU for attitude.

Parts

The geometry is the author's whole-robot STEP export, split into one component per link and placed as exported. Servos, the ESP32 and the IMU are part of that export.

Bill of materials

5 x standard hobby servos, ESP32 dev board, SparkFun BNO08x IMU (Qwiic), a second ESP32 with two joysticks as the remote, battery, M3 hardware, printed parts.