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Separating the Main part with its support structures.
Finalizing, curing, and finishing of the finished parts.
The main form of input for making a physical model is a three dimensional model of
the object which is made from a modelling software like Solidworks, Catia etc. Fig
2.1 shows the step by step procedure for rapid prototyping. As an alternative to
modelling, an existing physical part may be scanned digitally. This process of getting
a three dimensional model from a physical part is not a clear-cut and accurate
method. The resolution of the part would be less but may be improved by using laser
digitizer or a machine which is purpose built to measure co-ordinates.
The solid model designed on the modelling software needs to be converted into a
more machine readable format which is called a STL file. The STL file is made of
triangular faces which put together form the model. This file contains all the x, y and
z co-ordinates of the whole model which forms of the basis of three dimensional
printing. The STL file is then sliced by horizontal planes into thin slices. The
thickness of the layer is equal to the distance between two consecutive adjacent
planes. Depending upon the type of the STL model, a support structure may or may
not be generated. The model is imported into the software which mainly acts as a
medium between the machine and computer. The orientation is then adjusted to suit
if required and the model is set to start printing.
The co-ordinates and boundary information of each layer is sent one by one to the
rapid prototyping machine after it is sliced. The machine now starts to build the
model layer by layer as per the information stored in the STL file, conveyed by the
mediating software.
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