Mechanics
The
3d Printer is essentially a system of screws and belts,
all run precisely with stepper motors. The
screws and belts control the x, y, and z axis of the
printer.The
x and y axis are most often
controlled by stepper motors
attached to a belt system, and
the z axis is controlled by a
screw.
http://www.adobe.com/support/freehand/basics/3d_animations/images/xyz.gif
Stepper motors are brushless DC
motors that are characterized by
small, precise, radial movement.
This component is the heart of
the 3d printer for it allows
very controlled movement on each
axis, making the resolution of
the physical object very high.
http://www.seeedstudio.com/wish/wp-content/uploads/2011/09/nm17b12s_w400.jpg
Just
as the belts and screw
systems are controlled
by the stepper motors, a
processor controls
the stepper motors. When
the computer breaks down
the digital object into
slices, it is actually
assigning a value for
the x and y motors for
each point on the now
sliced object. The z
coordinate corresponds
with each layer or
slice. Once the x and y
motors complete each
coordinate, the z motor
moves to the next plane
and the process begins
again. The layers can be
clearly seen in the
printed whistle to the
right.
http://www.cnccookbook.com/img/OthersProjects/3DPrinting/RepRapWhistle.jpg