User`s manual

From a 3D model to a printing le

The real “secret” of three-dimensional printing is the transformation of three-dimensional object

into a sequence of two-dimensional slices that overlaping, reconstruct the object. Imagine a series

of slices of bread: If the stack rebuilt the loaf from which they were cut.

In the case of 3D printing every slice may consist of two-dimensional shapes not connected together

as it is their sum to create the nished object.

Thanks to this breakdown, the object can be complex as desired because the printer will draw with

the plastic one layer aer another without overlap; a square or a doodle for the printer have the

same diicult.

The most important work the soware makes is starting from the 3D model – usually a mesh of

triangles in space called mesh – and transforms it into a sequence of slices according to a number

of parameters (slicing). Because the process is completed correctly the mesh should be closed and

not have triangles that are oriented incorrectly confusing the “inside” and “outside”. It happens that

some model is made to art: at this point or the soware that does the slicing manages to repair the

mesh or the result of errors that will prevent the correct reproduction of the object.

A good STL, a good slicing, a good print

The STL le is the starting point for the entire procedure, so from the le should be removed anything

you don’t want to print (hidden objects, etc.).

The 3D drawing must be a solid and not a solid sum interpenetrate or match. Similarly, the design

must be as clean and precise as possible: articles must have an inside and an outside well dened

so that the surfaces perfectly match each other without leaving holes. most 3D design soware gives

you the possibility to carry out an analysis of borders to check for holes.

The 3D drawing must be oriented in such a way as to have a face adjacent to the XY plane of your

drawing soware: in other words, the design should not “oat in a vacuum”, otherwise the machine

will not print.

If you’re working on a STL downloaded from internet or given to you by a client, there are free so-

ware for checking and correction of STL as Netfabb.

The “slices” are printed in a specic format (called G-Code); This format is nothing more than a set of

instructions for moving the instrument (cutter, laser or extruder head) along a path X, Y, and Z axes.

Each slice contains the movements on two axes, moving the press plane and motor commands that

extrudes the molten plastic to create one aer another the layers that make up the object. At the end

of each layer le commands move the Z-axis by lowering the print of that plan just enough to add

the new layer.

Every 3D object can be transformed with the process of slicing in a variety of G-Code les, each dier-

ent from the others because slicing parameters generated using dierent: for example the slices have