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DIRECT DIGITAL MANUFACTURING PART THREE:HOW TO IDENTIFY OPPORTUNITIES

3D PRODUCTION SYSTEMS

By Scott Crump, CEO, Stratasys, Inc.Direct digital manufacturing (DDM) can be diffi cult to characterize because it does not fi t neatly into previously established categories built around conventional manufacturing processes. Due to its unique processing capacities and innovative advantages, it can be a challenge to easily identify target applications for DDM. Therefore, it is vital to understand how to recognize the opportunities.Compounding the diffi culty in learning to recognize when DDM should be considered is the breadth of opportunities. Unlike conventional manufacturing processes that are constrained to process specifi c classes of materials or targeted towards specifi c product characteristics, DDM is successfully used in a wide array of industry for a broad range of products manufactured from a many classes of materials. In this aspect, DDM is much like machining but without the manufacturability constraints.With so many opportunities to leverage the process, companies may overlook good applications that could benefi t from DDM. To prevent this oversight, there are fi ve common traits of successful DDM implementations that designers and engineers can use to rapidly identify the next product that will benefi t from DDM.
Figure 1: Complex geometries are likely candidates for DDM

DDM OPPORTUNITY INDICATORS

Complexity Although part complexity is not a requirement for DDM, the benefi ts that can be derived usually increase proportionally to the component’s design complexity (fi gure 1). The reason is that for extremely simple shapes there can be multiple manufacturing methods available that can deliver a part reasonably quickly and affordably. This is true because conventional manufacturing methods’ time and cost are usually proportional to the complexity of the part. So, as design becomes more intricate, or more feature-laden, the cost of tooling, machining, molding, casting, stamping and forming are likely to rise. Likewise, the lead time to receive the fi rst manufactured parts also increases.With DDM, there is no link between complexity, time and cost. Unlike traditional methods, manufacturing lead time and expense are more closely tied to the size and volume of a part than they are to the component’s design. As a result, the advantages of DDM over traditional methods are more signifi cant with more complex components. Large Up-front Investment Manufacturing has an investment in each of its products. There is a substantial investment of labor, time and money for the creation of tool paths, fi xtures, molds and machinery. For example, a single injection mold can cost $75,000, or more, and take eight to 16 weeks to make. As the initial investment of money and time grows, DDM becomes an increasingly viable alternative.When products are made with DDM, there are no tooling cost and no waiting for the fi rst production parts. Since DDM eliminates tooling cost and expedites production, it minimizes the start-up investment for a new product. For a manufacturing company, this translates to better cash fl ow, improved profi t and decreased debt. Lowering the initial investment also opens the door to more product introductions and the launch of products with low projected annual demand. With DDM, the high amortization cost for tooling of a small demand item is no longer a decision making factor. Rather, companies may elect to create the new product and build a new market without consideration of the cost per unit attributed to manufacturing start-up expenses. Redesign Conventional manufacturing processes are best suited for fi xed and static production runs. Any change to a product’s design results in an unwanted investment of labor, time and money. Once in production, design changes are expensive and time consuming. Therefore, the goal with current manufacturing processes is to minimize changes to maximize productivity and profi t. DDM circumvents this traditional rule. Since DDM promotes the freedom to redesign at will, any product that is likely to warrant design revisions becomes a candidate for the additive manufacturing process (fi gure 2). When using DDM, manufacturing a revised design is simply a matter of modifying
Figure 2: Freedom to redesign at will even complex geometries.

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