As continuation to the previous post....

Fused Deposition Modeling:

    The set up in this process consists of an extrusion nozzle which follows a tool path that is defined by the CAD file. This nozzle is heated which melts the material (mainly thermoplastics or wax) and is movable with the help of motors to form layers that are extracted from STL file. The nozzle can turn the flow on and off.  

     The materials are deposited in layers as fine as 0.04 mm (0.0016") thick, and the part is built from the bottom up – one layer at a time. FDM works on an "additive" principle by laying down material in layers.

Picture depicting FDM process

Solid Ground Curing (SGC):

       In this process a plate is charged selectively and coated with black powder which results in photographic mask of clear and opaque areas for a single slice of the part. This layer is placed over photopolymer and exposed to a UV lamp which hardens the polymer selectively. The unhardened polymer is removed from the surface and affine layer of wax is deposited and hardened which acts as support. After completion of the process the wax is melted and removed.

    This process has many advantages as the process is non time consuming and post curing is eliminated.

    The step wise procedure can be found here:

http://www.efunda.com/processes/rapid_prototyping/sgc.cfm

The setup for SGC process

Laser Engineered Net Shaping (LENS):

      This process fabricates the model directly from the CAD model using metal powder injecting into a molten pool created by a focused, high powered laser beam. Simultaneously the substrate on which the deposition is occurring is scanned under the beam/powder interaction zone to fabricate the desired cross sectional geometry. Consecutive layers are sequentially deposited, thereby producing a three-dimensional metal component.