Fused deposition modelling (FDM) is a fast growing rapid prototyping (RP) technology due to its ability to build functional parts having complex geometrical shapes in reasonable build time. The dimensional accuracy, surface roughness, mechanical strength and above all functionality of built parts are dependent on many process variables and their settings. In this study, five important process parameters such as layer thickness, orientation, raster angle, raster width and air gap have been considered to study their effects on three responses viz., tensile, flexural and impact strength of test specimen. Experiments have been conducted using central composite design (CCD) and empirical models relating each response and process parameters have been developed. The models are validated using analysis of variance (ANOVA). Finally, bacterial foraging technique is used to suggest theoretical combination of parameter settings to achieve good strength simultaneously for all responses.

<p>To solve the tool-making bottleneck, it is fundamental to integrate rapid manufacturing methodologies for rapid tooling, which reduces the lead-time to manufacture the tools while improving their quality. Rapid tooling (RT) is a progression of rapid prototyping (RP). RT is the art of producing tooling directly from CAD models of the part. RT technology plays a major role in increasing the pace of tooling development. This paper describes the role of RT according to the current market situation. An ample review of examples of rapid tooling indicates a new trend of tooling practice. This trend in manufacturing based on rapid prototyping and rapid tooling has already had a dynamic impact on the engineering environment.</p>

Electrical discharge machining (EDM) is one of the earliest non-traditional machining processes. EDM process is based on thermoelectric energy between the work piece and an electrode. A spark occurs in a small gap between the work piece and the electrode and removes the material from the work piece through melting and vaporising. The electrode and the work piece must be electrically conductive in order to generate the spark. Various types of products can be produced and/or finished using EDM such as dies, moulds, parts of aerospace, automotive industry and surgical components etc. This paper presents the various research issues in EDM along with the modelling technique in predicting EDM performances.

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