robotic arm 3d model

Create a simple 3D robotic arm using basic geometric shapes. Use cylinders for the joints, rectangular prisms for the arm sections, and a circular base. Include 4 servo motors: one at the base for rotation, one at the shoulder to move the main arm, one at the elbow to bend the forearm, and one at the gripper to open and close the claw. The design should be simple, educational, easy to understand, and suitable for a school project. All parts must be clearly separated and movable.