What you can learn with the SCARA robot
What a SCARA is
Selective Compliance Assembly Robot Arm: two links that rotate in a horizontal plane, a vertical ball-screw spline and a wrist. It is stiff vertically and slightly compliant horizontally, exactly what inserting parts requires. It is faster than a 6-axis arm in the plane and has a small footprint, which is why it dominates electronics assembly.
Right and left arm
Almost every point can be reached with two elbow postures. The controller never switches posture on its own, because the arm would sweep everything around it. In the Move tab you can switch it and see that the tool stays in the same place with different joint angles.
Jump and LimZ
The typical SCARA move is Jump: rise, travel and descend in a single command, with arches that overlap the segments to save time. LimZ sets the maximum height. It must be enough to clear obstacles with the part hanging below, but no more, because every extra millimetre costs cycle time.
The Weight parameter
The controller tunes acceleration and motor control to the load you declare. If you declare less than the real load, the arm arrives with too much energy and vibrates when it stops; with a 0.1 mm tolerance, the component won’t go in. If you declare more, the robot lowers its acceleration and loses speed.
Insertion
The approach is done with Jump to a few millimetres above the hole and the insertion with Move, slow and straight. That way the residual vibration dies out before the component touches the board, and the arm is no longer moving horizontally as it goes in.
Modes and safety
In TEACH the robot moves only with the enabling switch held and at reduced speed. In AUTO the cell door must be closed: opening it stops the robot. The emergency stop switches the motors off and the brake holds the vertical spline.
Other robots in the lab: KUKA arm · Cartesian · Delta · Cobot · Kinematics. More simulators in Labs. Educational simulator: the figures are representative and do not replace the manufacturer’s documentation or the risk assessment of a real installation.