The robotic arm used in the project was a modified LYNX 5 which contains 5 DOF: shoulder flexion / extension (S1), shoulder abduction (S2), elbow flexion / extension, wrist flexion / extension, and hand grasp / release. Each DOF was controlled by one servo, except the shoulder abduction, which was controlled by 2. The shoulder abduction process requires lifting all of the servos to the end effecter, and thus requires the most amount of torque. Each servo motor was controlled by PWM with an update rate of 20Hz and a pulse ranging from 1.0ms < Pulse Width < 2.0ms, where 1.5ms is center rotation of the servo.
To handle the greater amount of torque required for this project, S1 was modified from a smaller servo to a larger servo to meet torque requirements. Additionally, a redesign of the base was needed and a magnetic mount was attached for convenience. The magnetic mount allowed the robot to be mounted on the vertical as opposed to the horizontal to give an appearance of a human arm.