LEGO MINDSTORMS Robot Inventor
This model makes a 4-leg walker using only one motor. It has the same dimensions and walking geometry as the 4-Motor Walker except with only one motor. Because all four legs move together at the same speed, gears and axles can be used to transmit the power from one motor to all four legs. However, unlike the 4-Motor Walker, it cannot turn, since all the motors always move together.