The objective of this work is to bring about a revolution in Manufacturing Industry from Mass-Production Manufacturing to Tailor-Made Manufacturing in which products are manufactured according to the whims of the customer. For that, Rapid Prototyping (RP) method was used for making a prototype or pattern for casting a product. A new method for investment casting was found out using RP: Fused Deposition Modeling (FDM). RP parts were also tested for using them as a pattern for sand casting. Software named “AUTOCAST-X” was used for designing and simulating zero defect casting. A case study of a middle disc of Oldham coupling was done, in which the disc was produced using both the new investment casting and the sand casting and the parts made by both the methods were compared. Views of foundry personnel were recorded on using RP Patterns in sand casting. They found it very helpful in case of intricate and complicated pattern designs which cannot be made by a pattern maker in wood or metal.Prototyping