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In some additive manufacturing processes, support structures are required while building parts, for structural stability as well as for some functional aspects. Support structure should be designed in a way that it should withstand the weight of the part especially overhanging features of the part to avoid distortion and mishap. This paper deals with design and fabrication of tailored support structures for some special cases. From the understanding obtained through various literature, initially, a broad classification of support structures is presented. Based on that, application-specific support structures were designed. Two different support structures were designed, analyzed and fabricated successfully. After fabrication, support structures were easily removed from the part manually.

Metal based additive manufacturing (AM) techniques are continuously adopted by aerospace, automobile, defense, and healthcare industries. The primary concern for the components used in these applications is high precision. Despite being able to produce complex shapes, they lack in precision due to the distortions in shape and size of the part during and after fabrication. Distortion is the deviation of the part from its actual shape or dimension. Eventually, shape deviation has an unfavorable effect on the part functional performance which will hinder their use for critical technological applications. Even though, the temperature gradients during the process build affect these errors; they need to be studied in detail to fix the causation of these errors. In this paper, we review and classify the causation for shape and size distortion that occurs in metal additive processes. The approach to classification is multi-faceted and are based on the geometry of the fabricated part, the material used, process-related parameters, part orientation and physical phenomenon that occurs during the process. This work would help understand the root cause of distortion in major commercially successful metal AM processes and eliminate the need for costly trials.