Low-cost SCARA ROBOT, 4-AXIS. I hate the robotic arm like a big head swaying with a big head. . . The two-axis motors are all inside the circular base, and the small three- and four-axis motors are hidden in the arm, and the cables are not exposed to them. After replacing it with a ball nut, it replaced the damn expensive ball screw spline and complained again - it was too expensive.