 |
 |
|
An Overview
Rapid Prototyping refers to technologies that provide an efficient process for constructing physical models of mechanical parts that have been designed utilizing Computer-Aided Design (CAD). The ultimate goal of this process is to reduce turnaround time.
The resulting models are constructed utilizing additive fabrication instead of the subtractive or compressive processes typically used when manufacturing parts. Additive fabrication, sometimes referred to as solid freeform fabrication, consists of incrementally building the model by placing layers of materials (e.g. liquid, powder,) on top of each other and joining the layers together.
These models assist in reducing development time by providing a representation of the part being designed that can be physically examined. This examination can occur concurrently with customers and co-workers in different departments allowing for a better understanding of the part being designed. This concurrent examination will also provide an opportunity for earlier determination of issues from differing aspects that could prove to be costly if discovered later in the design or production process. This examination can also include design testing in addition to visual observation of the model allowing for early detection of design defects.
The process for constructing models using an additive process typically consists of five steps:
Step 1
Create a CAD model of the design. Consists of conceptually building the desired model within a CAD software application.
Step 2
Convert the CAD model to a STL format. STL (abbreviation for stereolithography) is a standardized file format that represents the model as a 3-D surface consisting of planar triangles. The model specifications in the CAD application are output into a file containing the STL format.
Step 3
Slice the STL format into thin cross-sectional layers. A pre-processing program prepares the STL file by "slicing" it into thin layers (0.1mm to 0.7mm in thickness). Any structures needed to support the model as it is built are also generated.
Step 4
Construct the model one layer on top of another. Construction occurs by placing the layers defined in the previous step on top of each other.
Step 5
Clean and finish the model. Referred to as post-processing, remove the model from any supports and performing any curing, cleaning, or other needed surface treatments.
The technologies offered by DPT for implementing this process are Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), Stereolithography (SLA), Laminated Object Manufacturing (LOM), Electron Beam Melting (EBM), Direct Shell Production Casting (DSPC), and 3D Printing (3DP).
In addition to using Rapid Prototyping to build models to ease communication and for testing, this process can also be used for rapid tooling and manufacturing.
Rapid tooling refers to automatically building production quality tools or molds used for building production tools, reducing the amount of time needed to produce such tools in the typical manufacturing process. There are two types of rapid tooling, indirect and direct. In indirect tooling, the models are used as patterns for the molds and dies for manufacturing processes. In direct tooling, a production quality part or a mold for the part are built.
Rapid manufacturing refers to automatically producing salable products. This method of manufacturing is especially applicable for short production runs, when the materials of the part are available for this method, when a custom part with unique specifications are desired, or when a part cannot be built with the typical manufacturing processes.
Disclaimer
DPT may not provide some of the services and/or techniques presented in the Knowledge Center. For a full list of services we do offer, please visit our rapid prototyping page.
