3D printer part2

3D printing is a logical extension of the idea of  developing models and prototypes by more automated methods in which product designers make their own rapid prototypes, in hours, using sophisticated machines similar to inkjet printers.

A 3D  printer essentially  works  by extruding  molten plastic  through  a  tiny  nozzle  that  it moves  around  precisely  under  comp uter control.  It  prints  one  layer,  waits  for  it  to dry, and  then  prints  the  next  layer  on top. A typical 3D printer is very much like an inkjet printer operated from a computer. It builds up a 3D model one layer at a time, from the bottom upward, by repeatedly printing over the same area in a method known as fused depositional modeling (FDM). Working entirely automatically, the printer creates a model over a period of hours by turning a 3D CAD drawing into lots of two-dimensional, cross-sectional layers—effectively separate 2D prints that sit one on top of another, but without the paper in between. Instead of using ink, which would never build up to much volume, the printer use thermoplastics (plastics that  melt  when  you  heat  them and  turn  solid  when  you  cool  them  back  down), and  typically  one  called ABS (acrylonitrile butadiene  styrene). ABS is perfect  for  3D  printing. For one thing, it's a  solid  at  room  temperatures  and  melts  at  a  little  over  100°C  (220°F). For another,it's  a  whiteishcolor  chemicals  in paint yellow  color  in  its  raw  form,  but pigments  (the )  can  be  added  to  make  it  virtually any color  at  all.