DEVELOPMENT OF ELECTRIC DISCHARGE MACHINING (EDM) USING SOLENOID ACTUATOR FOR EDUCATIONAL PURPOSE

The increasing number of materials with variation in properties, especially hard-to-cut, leads to the need for an advanced machining method to process such material. Electric Discharge Machining (EDM) is one of the advanced machining methods widely used for hard-to-cut alloys. The EDM process uses an electrode as the conductor of electrical current to erode the metal alloys and is supported by other components. Due to EDM's high cost and high energy consumption, developing a low-cost EDM and simpler EDM setup is necessary, especially for educational purposes in laboratory activity. However, the EDM design and setup required to produce the desired “spark” have always been a challenge for researchers and manufacturers. In this research, a small-scale EDM setup was built. A solenoid actuator is used to generate simple mechanical movement. The movement is used to control the gap between the workpiece and the electrode to produce a spark. The solenoid actuator is used because of its low cost and simple mechanism. The proposed EDM setup is successfully fabricated and works appropriately by generating sparks and a hole cavity during the process. There are six cavity holes produced in mild steel workpiece during the experiments with various parameters such as current (5A, 7A, and 10A) and frequency (10 Hz and 20 Hz). The varied parameter shows that the higher current and lower frequency removed more materials. In contrast, the higher frequency produced a better quality of the cavity hole. However, the lack of flushing quality on the material debris during the process results in the formation of excess metals around the edge of the hole.

Multi-objective Optimization of Linear Proportional Solenoid Actuator

This paper employed a multi-objective Genetic Algorithm (GA) process to optimize the structure parameters of Linear Proportional Solenoid (LPS). And designed objectives include magnitude of static push force, stability of push force with displacement in working range and push force to mass ratio. A two-dimensional finite element analysis model is presented to reduce the large calculation time generated by GA process. The optimization process result of LPS shape parameters is obtained and the optimal LPS is manufactured. Through using a high-precision measuring device in the static push force test, a comparison result between conventional shape and optimal shape shows that the proposed optimization strategy is feasible.

A Development Study of a New Bi-directional Solenoid Actuator for Active Locomotion Capsule Robots

A new bi-directional, simple-structured solenoid actuator for active locomotion capsule robots (CRs) is investigated in this paper. This active actuator consists of two permanent magnets (PMs) attached to the two ends of the capsule body and a vibration inner mass formed by a solenoidal coil with an iron core. The proposed CR, designed as a sealed structure without external legs, wheels, or caterpillars, can achieve both forward and backward motions driven by the internal collision force. This new design concept has been successfully confirmed on a capsule prototype. The measured displacements show that its movement can be easily controlled by changing the supplied current amplitude and frequency of the solenoid actuator. To validate the new bi-directional CR prototype, various experimental as well as finite element analysis results are presented in this paper.