Rapid prototyping is fast emerging as a preferred manufacturing method among global manufacturers to bring products faster to the market. As a part of this process, manufacturers are using varied tooling methods to design pre-production models, limited parts of production runs, and even production quality tools of the rapid prototyping process. Die casters are using a variety of rapid tooling methods to produce pre-production models, limited runs of production parts and even production quality tools subject of running up to 100,000 parts in certain cases.It was during the year 1980, when developments in rapid prototyping started with the help of computer aided design or animation modeling software. These tools were used to convert the virtual designs into cross-sections constituting the physical dimensions of the model. The procedure can be compared to that of a topographical model where the layers represent to the elevations in the model. The virtual model is then transformed into a real design through either additive or subtractive prototyping.
Additive Prototyping
In this method, the model is created by producing crosssections using sequential micrometer or millimeter-thick layers of liquid plastic, powdered plastic or any other engineering material. The normal interface between the CAD software and rapid prototyping machines is the STL (stereolithography) format that is similar to printing. The layers posited by the prototyping machine that fit to the virtual cross section from the CAD model, are fixed together or fused (often using a laser) to produce the final shape.
The main benefit of additive prototyping is its capability to create almost any shape, except trapped negative spaces.
Substractive Prototyping
Substractive prototyping is a conventional method of rapid tooling that is used create a die tool. In place of machning the steel in the tempered condition and afterwards heat treating it, pre-hardened steel used. The process helps in shortening lead time. Sophisticated cutting tools provide for machining of steels up to 40-42HRC. Die life can increase from a few thousand shots to tens of thousands, which depends on configuration of the part.
Substractive prototyping is a conventional method of rapid tooling that is used create a die tool. In place of machning the steel in the tempered condition and afterwards heat treating it, pre-hardened steel used. The process helps in shortening lead time. Sophisticated cutting tools provide for machining of steels up to 40-42HRC. Die life can increase from a few thousand shots to tens of thousands, which depends on configuration of the part.
The primary advantage of subtractive process is its ability to create very accurate tools with superior surface finish.
Advantages of Rapid Tooling
Some of the important advantages of rapid tooling are -
- Variety of tooling methods for unique and specific requirements
- Designs can be quickly transformed from prototype to production
- Rapid tooling cuts production time
- Possible to create complex designs
- Economical
