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Lesson 05 - What are the Types of Pattern ?

 Single-piece or Solid Pattern • Solid pattern is made of single piece without joints, partings lines or loose pieces. • It is the simplest form of the pattern. • Simplest type, inexpensive used for limited production. • Typical single piece pattern is shown in Fig. Two-piece or Split Pattern • When solid pattern is difficult for withdrawal from the mold cavity, then solid pattern is splitted in two parts. • Split pattern is made in two pieces which are joined at the parting line by means of dowel pins. • The splitting at the parting line is done to facilitate the withdrawal of the pattern. • A typical example is shown in Fig. Cope and Drag Pattern • In this case, cope and drag part of the mould are prepared separately. This is done when the complete mould is too heavy to be handled by one operator. • The pattern is made up of two halves, which are mounted on different plates. A typical example of match plate pattern is shown in Fig. Loose-piece Pattern • Used when pattern is diffi...
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Lesson 04 - What is Pattern ?

What is pattern? • Pattern is the principal tool during the casting process. • A pattern is a model or the replica of the object (to be casted) • It may be defined as a model or form around which sand is packed to give rise to a cavity known as mold cavity in which when molten metal is poured, the result is the cast object. • A pattern prepares a mold cavity for the purpose of making a casting   Objective of a Pattern Pattern prepares a mould cavity for the purpose of making a casting. • Pattern possesses core prints which produces seats in form of extra recess for core placement in the mould. • It establishes the parting line and parting surfaces in the mould. • Runner, gates and riser may form a part of the pattern. • Properly constructed patterns minimize overall cost of the casting. • Pattern may help in establishing locating pins on the mould and therefore on the casting with a purpose to check the casting dimensions. • Properly made pattern having finished and smooth...
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Location: United States
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Lesson 03 - Advantages, Disadvantage & Application of Casting

Advantages of Casting • Product can be cast as one piece. • Very heavy and bulky parts can be manufactured • Metals difficult to be shaped by other manufacturing processes may be cast (Ex. Cast Iron) • Best for mass production • Complex shapes can be manufactured Disadvantages of Casting • Casting process is a labor intensive process • Not possible for high melting point metals • Dimensional accuracy, surface finish and the amount of defects depends on the casting  process • Allowances required Applications of Casting • Transportation vehicles(Ex. engines) • Machine tool structures. • Turbine vanes • Mill housing • Valves • Sanitary fittings • Agricultural parts • Construction &atomic energy applications.
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Lesson 02 - Casting Terminology

• Pattern: An approximate duplicate or true replica of required product of casting • Flask/Box: The rigid metal or a wooden frame that holds the moulding material • Cope: Top half of the moulding box • Drag: Bottom half of the moulding box • Core: As and shape that is inserted into a mould to produce internal features of a casting such as holes. • Riser: A vertical opening in the mould • Act as a vent for gases • Helps to confirm that the mould is completely filled • Act as a reservoir of molten metal to feed and compensate for shrinkage during solidification of a casting • Gating System: Channels used to deliver the molten metal to the mould cavity • Sprue: The vertical passage in the gating system • Runner: The horizontal channel of the gating system • Gate: Channel which connects runner and mould
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Lesson 01 - What is Casting ?

Casting process is one of the earliest metal shaping techniques known to human being. • It means pouring molten metal into a refractory mold cavity and allows it to solidify. • The solidified object is taken out from the mold either by breaking or taking the mold apart. • The solidified object is called casting and the technique followed in method is known as casting process. Six basic steps in this process: • Place a pattern in sand to create a mold. • Incorporate the pattern and sand in a gating system. • Remove the pattern. • Fill the mold cavity with molten metal. • Allow the metal to cool. • Break away the sand mold and remove the casting
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Location: United States
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