Re: IGES and other solid model files to GCode

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Brad Eyben" <abeyben@t...>
wrote:

> Conversion from Iges to Gcode would be something I'd like to see.
> I must not understand, Jeff's question was
>
> Does anyone know a good program for converting solid models like an

IGES to

> GCode to run on a CNC mill?
>

The question started the confusion. IGES is what is called a neutral
file format for exchange of design data. It has many different kinds
of "entities" that may be used. These entities include simple lines,
points, arcs, splines. Annotation, dimensions, and symbols may also
be present. In addition there are a couple dozen different types of
surfaces that may be included, and one that is called a solid which
is nearly identical to the STL format. Note that any and all these
entities may be included within the same file.

Iges is NOT a solid format. Most of the so called solid modelers are
actually using Brep surfaces. Brep stands for Boundary
Representation. In Iges file talk, this is most closely defined with
Trimmed Nurbs surfaces. Exporting a parametric solid model to an
iges format will usually result in loss of history and parametric
data. Probably a good thing when creating toolpaths form a finalized
design.

Iges is an open standard and hence is available to all the Cad-Cam
companies for their use in sharing data. The Cad companies in
particular like to keep their file formats a secret. Because of this
and sloppy/untrained programmers, there are many IGES filters that
export improperly formatted data, and many cad and cam systems cannot
handle the complexity of Trimmed Nurbs and other surfaces because of
2D limitations or other problems recognizing/using the 3D surfaces.

Iges has been around for a while. It has a fixed 80 column, ascii
format that dates back to punched cards and chads.

Vector Cam 3D has a nurbs based CAD surface modeler that supports
trimmed surfaces and can import IGES, STL, and DXF, including mesh
and nurbs surfaces. We offer the full version to the group on
special for $595. It includes both 2d and 3D capabilities for
milling, routing and other table based systems like plasma and laser,
and also includes Lathe and 2 or 4 axis wire EDM. The basic program
includes a pair of Trutype stroke fonts for centerline engraving, a
gear design program, and our Macro Tool Bar for adding
programmability without a degree in computer science.

Best Regards, Fred Smith- IMService

Listserve Special discounts and offers are at:
http://www.imsrv.com/hobby/grp.html

We are THE source for low cost Cad Cam