Rapid prototyping is the realization of an idea into a physical object in order to provide a representative of a finished product using rapid prototyping technologies to allow for appraisal and design modifications. The First rapid prototyping machine was first made available to markets in late 1987 meaning it is a relatively recent development. Rapid prototyping began as an expensive tool for manufacturing a physical model for design engineers to use to visualize their component designs. However in recent years the technology has advance so much that it is becoming cheaper to produce a component. (1)
The aim of this report is to provide an insight to rapid prototyping technologies by discussing various methods and provide the advantages and disadvantages of rapid prototyping itself.
2.0. Generic Rapid Prototyping Process
The basic steps in a rapid prototype process can be summarized into the following:
1. Construct a CAD model based on the desired design.
2. Convert the CAD model to and .STL file by slicing the model into layers.
3. Building on the rapid prototyping machine
4. Support material is removed and the model is finished and cleaned.
2.1. CAD Model Construction
A component or model is constructed on a CAD (Computer-Aided Design) program. This model will represent the desired physical rendering part to be built. This model must be built with closed surfaces which defines an enclosed volume. This means that the data must specify the inside, outside and other characteristic boundaries of the model, but this does not apply if the model itself is meant to be a solid as a valid solid model will automatically be an enclosed volume. This requirement ensures that all horizontal cross sections that are essential to the RP are closed curves to create a solid object. (2)
2.2. Convert to .STL file
The solid or surface model built using a CAD is next converted to a .STL format (STereoLithography). This creates a 3D model that can be used by the RP machines. The STL file format approximates the surfaces of the model using tiny triangles. Highly curved surfaces must employ many more triangles, meaning that STL files for curved surfaces can be rather large files. (2)
2.3. Rapid Prototyping
Most RP machines are automatic and require little to no input after initial setup. It is usual for an operator to leave a machine on a build overnight as some building processes may take up to several hours. The number of objects built at one time is dependent on the volume of the RP machine. (2)
This process put high responsibility onto the operator as generally some manual operations are necessary. Therefore there is a high chance of the model being damaged. The cleaning refers to the removal of any external parts and support materials that may have remained on the model. (2)
3.0. Different Rapid Prototyping Processes
3.1. Stereo Lithography Apparatus (SLA)
SLA machines use an excess of...