ASEA IRb6  Industrial Robot

This robot is one of the most successful Industrial Robots to be found on factory floors and although more than twenty years old, is still useful for moving parts and products, assembly processes and welding.

A Meccano model of this robot was made in 1987 and became ModelPlan MP 70.  The robot shown here is of similar appearance, although much smaller, therefore requiring less power to move the various joints and much easier to construct.

Meccano Asea IRb6 Industrial Robot

The robot has a number of interesting features.

1.  The body rotates on a base structure with the motor situated in the base.

2.  The shoulder joint between the body and the arm is spring loaded both in the forward and backward direction requiring less power to move it.

3.  The elbow joint between arm and forearm is counterbalanced.  

4.  A parallelogram of linkages ensures that when the arm is moved, the forearm always stays at the same angle relative to the horizontal plane. 

5.  The arm and forearm motions are each controlled by similar linear actuators driven by servo-motors.  This is a crosshead sliding on parallel guides and is moved by a capstan and wire. 

6.  By a system of internal linkages, the wrist is similarly configured to stay at the same angle with the horizontal. These arrangements reduce the need for complex programming for the wrist joint.

7.  The wrist has two motions - flexion and extension, and rotation.  These are controlled by an internal differential at the end of the forearm and driven from independent motors situated on the body.  This reduces weight at the end of the forearm.  When these motors rotate in the same direction, the wrist is lifted and lowered.  When they turn in opposite directions, the wrist is rotated.

Robot hand or gripper

8.  The gripper or fingers are controlled by a separate motor situated on the hand.  A clutch in the drive train prevents overload. 

9.  All motors or joints have digital encoders or potentiometers to provide positional feedback to the computer.

10.  The robot has been designed to be controlled by the Meccanisms Motivator, and programs are being  developed for it.

Robot controller and power supply

Michael Adler

November 2005