Rapid prototyping manufacturing

Rapid prototyping manufacturing is a process that employs additive fabrication technology ( rapid prototyping) to produce end-use items. Directly from CAD data, components are manufactured without molding, casting, or machining. The impact of rapid manufacturing is far-reaching, and the opportunities and advantages are extensive. This is why rapid manufacturing is heralded as the next industrial revolution.

Since the earliest days of rapid prototyping, experts have envisioned the application of the technology in the manufacturing process, and the focus of this vision has been on the initial cost and time savings that are realized when tooling is eliminated. Slashing hundreds of thousands of dollars and months from a product launch are significant benefits to manufacturers in all industries. However, the relative impact pales in comparison to the wide-ranging advantages that exist when rapid manufacturing is implemented.

Focusing only on the upfront benefits gained from eliminating tooling, the industry has failed to recognize many of the opportunities that rapid manufacturing offers. Some will yield unprecedented efficiencies; some will generate annual savings that far exceed the cost of a tool, and others will facilitate new methodologies that address age-old constraints imposed by conventional practices. Rapid manufacturing will benefit nearly every discipline within a manufacturing organization, and it will change fundamental business processes. When adopted en masse, it truly will be an industrial revolution.

Status quo

For the production of moderate- to high-volume quantities of metal or plastic parts, molding and casting are the prevalent processes. However, the tooling that is required demands a sizeable investment and a significant commitment to the product and its design.

Rapid manufacturing is an enabling technology since it eliminates the upfront expense and expedites manufacturing. For example, injection molds for small-to moderate-sized parts will often cost $20,000 to $75,000 and take upward of three months to complete. This investment of time and money is both a barrier to new products, especially for those with low forecasted demand and a drain on the cash flow and profitability of a company. Obviously, since it eliminates the need for tooling, rapid manufacturing facilitates new product launches and improves the corporate bottom line. For many, this is enough justification to pursue rapid manufacturing, but bigger gains are derived from the freedom to change a product’s design.

The rapid cycle times of tooling facilitate the inexpensive manufacturing of thousands, often millions, of parts. When amortized over large part quantities, the cost of tooling becomes reasonable and, oftentimes, almost insignificant. However, this presumes that tool will be operated for long periods of time; therefore, the tooling becomes a liability. With the prospect of additional costs and delays, product modifications are undesirable. Investing $5,000 to $20,000 for tooling rework, or $20,000 to $75,000 for replacement, is an unwelcome expense. Also, the losses grow since sales revenues are nonexistent while waiting for tool repair. Wherever possible, the ideal situation is to produce a perfect tool and keep that tool running for the life of the product. With this aim, the release of a work order for a production tool becomes a major commitment.

Sometimes use the proto mold is good option for some low production project as well, this will let you save some mold cost but have the perfect quality molding parts, a specially good idea for low volume production parts

However, commitment is not reasonable. Product life cycles are shorter, consumer demand is more fickle, and the odds of the redesign are high. In effect, the commitment becomes justified only when perfection is achieved. Without the perfect product, perfect design, and perfect mold, the investment in tooling becomes a constraint and an undesirable commitment. In many cases, when faced with a less-than-ideal scenario, companies will opt to continue manufacturing the product without change. The cost and time of retooling outweigh the advantages of the redesign.

The fundamental problem with tooling is that perfection is elusive, and striving for perfection is costly. It is unlikely that an organization is capable of perfection in every part, every assembly, and every product that it makes. Oversight, error, assumptions, and a whole host of unquantifiable variables can occur. Additionally, product demand may be overstated, and customer requirements may be misinterpreted.

Tools such as rapid prototyping help companies to uncover flaws, errors, and imperfections before releasing a production mold. And yet, problems still arise, only to be discovered when the first articles are molded. In many cases, the problems are minor and can be ignored. In others, the flaws are significant, but the repair is not an option because of cost and delays.

Tooling is a commitment. The moment the order is released for tooling, the design becomes frozen. There is little latitude for change and alteration. The options are limited to reworking, retooling, or building a stockpile of imperfect molded parts. Tooling is a constraint to making better products with better sales results.