This thesis work concerns the partial mechanical redesign and subsequent modification of the control algorithm of a lightweight manipulator to enable its use as a specialized cutting tool for a grape harvesting robot. A preliminary study of the components and factory configuration have been conducted, along with the analysis of the programming code from the manufacturer. Several kinematic chains have been investigated in order to allow the manipulator to properly handle a pair of harvesting scissors as an end-effector. Then, specific brackets have been designed and manufactured to install the scissors and their actuator onto the main structure of the manipulator, providing it with an additional degree of freedom.