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are a lot of possibilities for manipulating the Cad file, like the alteration of scale of the
output model or position of the model on the deposition table, etc. After the Cad file
is imported, the tool and material properties are applied. The material is now ready to
be deposited in the shape of the model desired to be printed on the deposition table.
The fully assembled machine looks as shown in Fig. 3.5.
3.4 Material characteristics for FDM
Fig 3.5 The fully assembled Fab at home in operation
One of the main properties of a material to be used with the test bed like fab at home
machine, is that material to be used has to be thixotropic, i.e in a semi solid state
which will enable a continuous, uninterrupted flow through the syringe barell. The
strength, mechanical properties of the end part is quite dependant on the bonding
between the individual strands or filaments. An investigation was done by Celine et
al [28] on the bond formation of parts made with a fused deposition modelling
process. The FDM process is analysed thermally and dynamics of bond formation
between filaments were evaluated by sintering. The results obtained from heat
transfer analysis and experimental data from sintering was used to study the degree
of bonding in the filament deposition process. It showed that the envelope
temperature had little effect on the neck growth than the extrusion temperature did.
An investigation was conducted by Ker ching ang et al [29] to find out the bonding
relationship and mechanical properties of structures formed by FDM processes. The
team have basically studied the effects of the FDM processes and its direct impact
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