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The criteria for selecting the most suitable parting direction include (in decreasing order):
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An
undercut feature is produced using a corresponding shaped core. This
involves higher costs in terms of special materials, additional tooling
and lower productivity. The number and volume of cores must be minimised
by selecting an appropriate parting direction.The parting line can be identified using its characteristic that it coincides with the projected boundary of the casting when viewed along the draw direction. The edges of the casting are first projected on to a plane perpendicular to the draw direction. The inner segments of the projected edges are ignored and the outermost perimeter (silhouette boundary) is determined. This is projected back to the casting and the corresponding landing points are determined. These points are connected in sequence to form the parting line. If multiple landing points occur (say, along edges parallel to the draw direction) then multiple alternatives of parting lines are available for selection. Depending on the shape of the component, the above method can generate flat, stepped or complex parting lines.




