The clone of product otherwise termed pattern which is to be cast is created using the method of casting. During the process the pattern is made used for cavity preparation. During the process it is in this container the substance for making the casting would be molted and poured. Patterns used for different types of casting vary as the types and needs. For instance casting, using sand would involve patterns made of plastics or metal or any material relative to this.
Care must be taken while carrying out the pattern making since the patterns once prepared can be used many times whenever the need arises in future. Proper and vital steps must be taken to prepare patterns of excellent quality which would have longer lifetime and there by helps in efficient casting process. The process of making patterns is coined as pattern making and the person who caries out the process is called as pattern makers. Pattern makers generally take up dual role of both designing patterns as well as making of patterns.
Need for Pattern Making :The making of patterns takes its need and importance in different areas of casting. For instance metals while sand cast would surely need patterns for the process to be carried out. Thus patterns are widely required for much process though the equipment used for making of patterns and techniques used for pattern making depends on various factors. Some of the factors to name are the size and the number of products to be cast, design used in casting process and so on. By taking proper stapes and guidelines in the making process of pattern which is widely needed one is sure to produce efficient quality patterns.
Guidelines for the Process of Pattern Making : Shrinkage Allowance :It is vital that proper steps and care must be taken to consider the shrinkage allowance also termed contraction allowance. This could be done by determining the type of metal used for casting process, its attributes or properties, the method used for carrying out the process of sand casting and so on. On proper analysis of above attributes the value determined for shrinkage or contraction allowance would vary. This is because some metals or alloys would have the attribute of shrinkage more than other.
Draft allowances :Allowances like draft must also be taken into account while carrying out pattern making process. That is while taking the pattern out from sand it is very essential to take steps such that the sand also does not come out along with the pattern. One such step in taking care of the above is to allow drafts while designing so that patterns can be narrowed down in side portions and this would make the process of removal in pattern from sand efficient.
Placement Analysis :It is essential for the person making patterns to review and analyze before hand about the placement of different systems like gating or risers in pattern. Proper predefined analysis on this aspect would enable the pattern making to be carried out efficiently and help in deriving an efficient quality product.