3D printing or additive manufacturing is a technology in which 3D objects are printed by depositing a thin layer of material layer-by-layer until a final product is produced. In this research work, it has been focused on the fabrication of a Portable 3D Printer for the manufacturing of sample parts by using Fused Deposition Modeling (FDM) process. The primary process parameters such as nozzle temperature, extrusion speed and fill density in addition to their interactions are studied. It has been observed that these process parameters influence the dimensional accuracy & extrusion time of the part produced by the process of Fused Deposition Modeling (FDM). The main objective of the research work is to create a reliable and cost efficient 3-D printer and to minimize the dimensional variation that usually occurs to plastic parts produced by 3D printers. Cartesian mechanism has been used where the print bed moves in the Z direction and the extruder moves in both the X & Y directions. The 3D printing filament that has been used is made of Polylactic acid or polylactide (PLA). The process involved 3D solid modeling to design, 3D printing with coated adhesive applied on the printing platform, measurement of dimensional variation of the printed parts and statistical analysis. Response surface methodology (RSM) based desirability analysis has been employed for optimization of FDM process parameters namely, nozzle temperature, extrusion speed and fill density. Mathematical models were developed and tested for accuracy & extrusion time using Design Expert 11 software for RSM application.