Graphics Reference
In-Depth Information
these to produce reasonable toolpaths.
Models can also be repaired manually using
a polygonal modeler. Another option is
MeshLab, an advanced, open source STL pro-
cessing and editing tool that is very powerful
but may be intimidating to beginners.
tool of choice. For more on how to use Slic3r,
see
Chapter 5
.
A fairly recent closed-source utility called
KISSlicer, available in free and pro versions,
boasts some unique features, such as adap-
tive sparse infill (using more material near
the edges of a print and less in the center)
and multi-extruder support (using different
material for separate models, support struc-
tures, and infill).
Though most slicing engines can be run as
standalone programs, they're commonly
built into integrated printer client packages
like ReplicatorG (
Figure 3-5
) and Pronterface,
so that the same interface used to control the
printer can also be used to load and slice 3D
models directly.
One type of modeling program may be
handier for, say, designing a mechanical part,
and another for sculpting an action figure.
As you become more experienced with 3D
printing, you might want to consider invest-
ing in a commercial STL analysis and repair
tool such as Netfabb Studio. While their Basic
suite works well for solving manifold issues
quickly and effectively, the Professional ver-
sion allows you to target specific elements of
the model for manipulation, decimation,
and re-meshing, as well as offering stable
Boolean operations to split up a model into
multiple parts. The Professional package al-
so offers built-in slicing utilities and drivers
for operating some of the printers directly, in
some cases entirely replacing the CAM/
client pipeline.
Slicing/CAM Software
Once you have a manifold, error-free 3D
model, it must be converted into specific
toolpath instructions that tell the printer
where to move the hot-end, when to move
it, and whether or not to extrude plastic
along the way. This process is sometimes re-
ferred to as
skeining
or
slicing
. The standard
format for these instructions is a simple pro-
gramming language called
G-code
.
Historically, most printers have relied on the
open source Skeinforge engine for prepar-
ing G-code from model files. Recently, how-
ever, alternative slicing programs have start-
ed appearing, most notably Slic3r, which has
been slowly overtaking Skeinforge as the
Figure 3-5.
Laying out a build plate in ReplicatorG.
All of these parts will print simultaneously.
Note that because a 3D print proceeds layer
by layer, the G-code to print a single copy of
a model is very different from the G-code to
print, say, four copies side by side. If you want
to print multiple parts per job, one option is
to simply lay out build plates, as they're
called, directly in your 3D modeling pro-
gram. Another option, which many find
more convenient, is to lay out build plates at
the CAM level. Many slicing engines, as well
as integrated print environments like
