This project involves modifying the calf (lower-leg) structure in the Unitree Go2 Pro’s 3D model. Existing 3D models of the Unitree Go2 Pro can be found online and are also available on Unitree’s GitHub. In this project, we will redesign the calf section so that, when fully extended, the calf and thigh align in a straight line. This modification will be applied to all four legs. Based on the reference diagrams, the goal is to create a SolidWorks assembly file in which each joint can be moved and tested to verify the new kinematic structure. Development of control, ROS2 integration, and Gazebo simulation will proceed separately after the modified 3D model is completed. In the Unitree Go2 Pro quadruped robot, the positions of the hip, thigh, and calf motors and gears will remain unchanged, but the structure of the calf section will be modified. The calf legs of all four limbs will be redesigned so that, when fully extended as shown in the diagram, they form almost a straight line. The length of the ground-contacting portion of the leg will remain nearly the same as the current design, and the hinge will be moved as far outward as possible so that, when pushed by the motor, it aligns almost linearly with the thigh. The front legs will maintain the current knee joint orientation and bending direction, but the rear legs will be modified to bend backward like a human knee. In other words, by swapping the outer casing of the thigh and calf leg on the left and right sides of the rear legs, the current inward-bending geometry will be reversed so that the legs bend outward instead. More specifically, the structure involves swapping the left and right orientation of the rear leg’s thigh and calf motor assembly, along with the lower leg structure, at the existing hip joint.