Under construction. Gripper to be added. The motors shown are Escap Swiss DC Motors with epicyclic reduction gearboxes. It is planned to replace these with steppers.
Construction is in Meccano. The robot is modular and has 6 motors as follows: Base rotation, Shoulder, Elbow, and two for the wrist (one for flexion/extension - one for rotation) These latter two motors are situated at the shoulder and drive co-axially through it with chain drives linked to a differential drive at the wrist. The result of this arrangement is that with both these motors at rest, shoulder and elbow motion have no effect on the wrist which stays in the same orientation to the floor throughout the movement. There is also a parallelogram linkage between the elbow and the shoulder so that elbow motion alone also results in the forearm remaining at the same angle to the floor throughout the movement.
Dr Michael Adler