EDM Knife-like Robotic End-Effector Driving Material Efficiency

Electric discharge machining (EDM) has a unique ability to accurately cut exotic, hard-to-cut materials such as titanium without physical contact, with negligible force and vibration. Such a characteristic makes it a promising machining technique to be combined with robot manipulators to maximise the flexibility of the working envelope. Such a combination enabled robots to make a more sustainable cut of large, monolithic, and complex workpieces used in relevant defence and aerospace industries. The concept has been proven through a feasibility study prototype using wire EDM, followed by rotational milling EDM configurations. The wire EDM configuration was challenging due to instability in the wire control system and tension. The milling EDM configuration has been proven successful for intricate geometries. However, it involves removing large amounts of material and is thus not ideal for large geometries or deep cuts. Thus, to further explore sustainable robotic EDM for large workpieces without vaporising significant amounts of scarce, exotic, hard-to-cut materials, new inventive tools are needed. Therefore, this research aims to present a new knife EDM (KEDM) end-effector concept as a pure simulation capable of making large, deep cuts on a titanium workpiece without interruption. Using the TRIZ algorithm, engineering constraints are overcome to propose a KEDM design that vibrates and operates like a large WEDM, without frequent wire breakage, setup, or restarts. This research further explores the proposed end-effector through a digital twin kinematic simulation to find and demonstrate the extent of the machined workpiece and the robot’s enlarged workspace.