In spite of design freedom, difficulties are sometimes encountered when transforming the engineering concept into a useful casting especially when the part was originally designed as a forging, stamping or fabrication.

Since the designer is concerned with a wide range of products, he is seldom wholly conversant with the casting process and so the part is designed without regard for a multitude of foundry variables. This is not to suggest the designer should obtain a comprehensive understanding of the casting process but rather that he should understand the fundamentals and refer additional queries to the founder who is a specialist in the casting process.

Ideally, the designer and founder should establish close contact during the preliminary stages of casting design so that the founder has an opportunity to use his detailed knowledge of the foundry industry and of his own products, for mutual benefit. In this way, comments on draft designs and pattern construction to suit specific foundry requirements, can be made with the least inconvenience. Consequently, major (late) changes in shape, dimensional tolerances and material specification may never arise. All these factors will probably be reflected in lower casting prices since the price of a casting is not simply a function of its weight but rather of the complexity of its shape and how this affects the cost of patterns, cores, molds, cleaning and casting yield.

The process of deciding to design and produce castings may be summarized as follows:

Preliminary

decision to use a casting
detailed design
inquiry, quotation, order

Production

pattern manufacture
sample/prototype casting production
bulk casting production

Very often only superficial contact is established between designer and founder until sample or prototype castings are produced. Occasionally, significant changes are requested at this stage by the designer, or the founder. The designer may have the impression he did not quite receive what he ordered and the founder may realize that a few relatively minor changes to the casting shape may make the casting much simpler and therefore cheaper to produce without affecting performance of the casting. For whatever reason, changes at this stage may mean lengthy, costly delays.

It is therefore essential to involve the founder from the beginning in the technical aspects of detailed design and minimize the occurrence of costly delays during the production stages.