Introduction to CAD/CAM Software
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CAD/CAM & CNC Software
CAD and CAM software packages are closely related to one another. In fact, they
share the first two thirds of their respective acronyms: CAD / CAM stand for
Computer- Aided Design and Computer-Aided Manufacturing. CAD programs
typically are used to draw the part being developed. CAM programs are used for
generating the tool path for the CNC machine that will cut the part. The
boundary between the two programs is often blurred as CAM programs often have
drawing capabilities and CAD programs often have “plug in” programs, or added
optional features, that allow them to generate tool paths.
CAD/CAM programs get installed on a computer and, contrary to popular belief,
learning to navigate the various functions is not rocket science. At first, the
different file formats and industry terms can be overwhelming. The good news is
that with each successive completion of the cycle, from drawing, to tool path, to
cutting a part, the method becomes more familiar and, subsequently, easier to
reproduce.
CAD Software Creates Drawings in 2D or 3D Formats. Traditionally, CAD
programs were primarily for engineering drawings and drafting. Its usefulness has
evolved beyond the tasks of precise dimensioning. Expanded capabilities now
include realistic renderings, dynamic analysis of moving elements and various
finite element engineering analyses.
A few standard 2D formats include: .DWG, .DXF, and .EPS. 2D CAD files typically
share the same graphical element in that they are vector-based. Vector graphics
consist of lines, arcs and other elements, in contrast to the pixels that make up a
raster file, like a digital photo. Vector graphics define these lines, arcs and
polylines with simple mathematical equations. 3D CAD files are similar, but
much more complex. Hundreds and even thousands of facets are calculated
when creating 3D CAD files such as, .STL, .3DS, and .RAW. This is just a
sampling of some of the more standard formats specific to different CAD
programs. Other formats, such as .IGS, define 3D surfaces and lines using
complex parametric equations. CAM software helps convert and manipulate a
CAD drawing into a tool path. CAM software imports a CAD drawing and saves it
in its own native file format. There are some programs that have both CAD and
CAM capabilities in one software package, which is a convenient feature, but the
transfer of files between two separate and standard CAD / CAM programs is not
complicated. In fact, most CAD and CAM programs have built-in capabilities to
both import and export several file formats.
The tool path generated by most CAM programs is in a standard manufacturing
programming language called G- Code. Consisting of “G” and “M” codes or
commands, a G- Code file guides the path of the cutter through the material by
outputting code for linear or circular motions. CAM software also embeds
parameters into the G-Code, such as tool width, tool path position, cut depth,
feeds and speeds, and others. These CAM parameters become increasingly
important as the files being cut become more complex. For instance, a 2D part
only requires that the depth of the cut be specified along with the path once the
tool reaches the desired depth. When a 3D part is being carved, the full program
description can consist of hundreds of thousands of G-Code commands
specifying the tool path. The program for 3D parts usually consists of very small
line segments that form the desired shape.
Another necessary step that CAM packages complete before outputting a tool
path is referred to as post-processing. This post-processing (or posting) customizes
the G-Code commands and parameters to communicate with a specific CNC
machine. The G-Codes and functions often remain the same, but posting serves
to format the syntax of the file to meet with the protocol of a given CNC machine’
s controller. Because of the great deal of freedom found in the international
standards for G-Code, individual controllers may require different formats. The
post-processing customizes the format to the specific controller being used.
The scope of CNC machining applications is so vast, that a good CNC Software
Suite (CAD / CAM) needs to accommodate a wide range of machining methods
covering several different markets.
CAD and CAM software packages are closely related to one another. In fact, they
share the first two thirds of their respective acronyms: CAD / CAM stand for
Computer- Aided Design and Computer-Aided Manufacturing. CAD programs
typically are used to draw the part being developed. CAM programs are used for
generating the tool path for the CNC machine that will cut the part. The
boundary between the two programs is often blurred as CAM programs often have
drawing capabilities and CAD programs often have “plug in” programs, or added
optional features, that allow them to generate tool paths.
CAD/CAM programs get installed on a computer and, contrary to popular belief,
learning to navigate the various functions is not rocket science. At first, the
different file formats and industry terms can be overwhelming. The good news is
that with each successive completion of the cycle, from drawing, to tool path, to
cutting a part, the method becomes more familiar and, subsequently, easier to
reproduce.
CAD Software Creates Drawings in 2D or 3D Formats. Traditionally, CAD
programs were primarily for engineering drawings and drafting. Its usefulness has
evolved beyond the tasks of precise dimensioning. Expanded capabilities now
include realistic renderings, dynamic analysis of moving elements and various
finite element engineering analyses.
A few standard 2D formats include: .DWG, .DXF, and .EPS. 2D CAD files typically
share the same graphical element in that they are vector-based. Vector graphics
consist of lines, arcs and other elements, in contrast to the pixels that make up a
raster file, like a digital photo. Vector graphics define these lines, arcs and
polylines with simple mathematical equations. 3D CAD files are similar, but
much more complex. Hundreds and even thousands of facets are calculated
when creating 3D CAD files such as, .STL, .3DS, and .RAW. This is just a
sampling of some of the more standard formats specific to different CAD
programs. Other formats, such as .IGS, define 3D surfaces and lines using
complex parametric equations. CAM software helps convert and manipulate a
CAD drawing into a tool path. CAM software imports a CAD drawing and saves it
in its own native file format. There are some programs that have both CAD and
CAM capabilities in one software package, which is a convenient feature, but the
transfer of files between two separate and standard CAD / CAM programs is not
complicated. In fact, most CAD and CAM programs have built-in capabilities to
both import and export several file formats.
The tool path generated by most CAM programs is in a standard manufacturing
programming language called G- Code. Consisting of “G” and “M” codes or
commands, a G- Code file guides the path of the cutter through the material by
outputting code for linear or circular motions. CAM software also embeds
parameters into the G-Code, such as tool width, tool path position, cut depth,
feeds and speeds, and others. These CAM parameters become increasingly
important as the files being cut become more complex. For instance, a 2D part
only requires that the depth of the cut be specified along with the path once the
tool reaches the desired depth. When a 3D part is being carved, the full program
description can consist of hundreds of thousands of G-Code commands
specifying the tool path. The program for 3D parts usually consists of very small
line segments that form the desired shape.
Another necessary step that CAM packages complete before outputting a tool
path is referred to as post-processing. This post-processing (or posting) customizes
the G-Code commands and parameters to communicate with a specific CNC
machine. The G-Codes and functions often remain the same, but posting serves
to format the syntax of the file to meet with the protocol of a given CNC machine’
s controller. Because of the great deal of freedom found in the international
standards for G-Code, individual controllers may require different formats. The
post-processing customizes the format to the specific controller being used.
The scope of CNC machining applications is so vast, that a good CNC Software
Suite (CAD / CAM) needs to accommodate a wide range of machining methods
covering several different markets.
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