Anatomy of a SCARA robot (3D)

← Robot list · SCARA page

Turn the robot with the mouse or your finger. Click an axis (a coloured circle or a card) to light up its ring and its axis and to read its description, press X-ray to look inside at the motors, gearboxes, controller and cables, and move each joint with its slider.

Turns the whole arm around the vertical column. The motor and the gearbox are in the column.

Turns the second link around a vertical axis at the end of the first one. Together with J1 it places the tool in the horizontal plane.

A rod slides up and down through the end of link 2, driven by a ball screw. It sets the height of the tool. The only linear axis.

Spins the tool around the vertical rod: it sets the angle of the gripper in the plane.

What is inside each joint?

Servo motors at the base and at the elbow, with harmonic gearboxes: stiff in the plane, which is why a SCARA is so precise.
Ball screw and spline shaft: the end of link 2 holds two motors, one for the up-and-down motion (J3) and one for the rotation of the tool (J4), both acting on the same hollow rod.
Brake on J3: gravity pulls the rod down, so the brake holds it when the power is off.
Cables and air pass through the hollow rod to the gripper (vacuum or compressed air).
Controller: in the column or in a separate box.

The angles of this 3D model are those of the drawing, with a zero chosen for display: they differ by a constant from the DH angles of the robot page. The model is simplified: the real inside depends on the make.