Re: [CAD_CAM_EDM_DRO] Digest Number 415

> Message: 8
> Date: Mon, 20 Mar 2000 22:10:18 -0800
> From: "Jay Tuckwood" <jtuckwood@...>
> Subject: BOBCAD FOR 3D?
>
> Greetings,
>
> I would like to export SolidWorks 3D IGES files to BobCad and machine

complex parts.

> Have any of you had success doing this?
>
> For the past 3 yrs, I have had great success exporting Autocad DXF files

to BobCad and creating G-code for machining 2 1/2 dimension holes and
pockets, etc. on my CNC Sherline mill.

>
> I know a real 3D CAM software package will set me back $10K or more (which

is out of the question). BobCad looks so promising, but I have had no
success with real 3D. (There must be a trick...and the support from BobCad
has been abysmal).

>

Jay, what you must understand to accomplish a transfer from solidworks to
Bobcad, is that Bobcad can only understand lines, points, and arcs. It has
no innate capability to understand what a solid or surface is. The IGES
import function in Bobcad translates many IGES entities into a form that
Bobcad can understand. Included in this are several IGES surface entities,
but NO solids. The surface translations are primarily an interpolation of
the edges and boundaries of the surface, and are often represented as a
series of short line segments, similar to a spline curve.

I have seen the best results if the Solidworks model is saved as a DXF
wireframe. I am not sure that it can save a file as an IGES wireframe, but
that should work just as well. One thing that you will have to be careful
with, is that the DXF files that Solidworks generates, have closed shapes
for surfaces. This results in duplicated entities along nearly every
boundary between one form and another. For example, on a cube, with sharp
edges, each edge will have 2 lines, one from each face of the cube.

When complex models are imported into Bobcad, they will often be
automatically "grouped" by the IGES translation. In order to get access to
the entities found in the little red boxes(to change them, or to use them
for a skin), simply select them, and make sure that they are "ungrouped".
Change-Ungroup.

One last option that may be of interest if you want to generate skins over
complex contours is our IGES2DXF translator. This program will generate
cross-sectional slices in any 2 normally oriented planes, through complex
Nurb Curve based surfaces (like Rhino generates). You determine if you want
X-Y, X-Z, or Y-Z slices, and how many within the extents of the model.
These slices are intended to be used by the skin function in Bobcad &
Vector, but could also be the basis for a Sintering/hot glue type of
machine.

In the Sintering/hot glue application, the original model would be an IGES
surface. Cross-sections would be developed by IGES2DXF, and then Bobcad
could generate either a zig-zag, or a spiral pocket to control the "tool" or
glue nozzle.

We have a free 30 day full working demo of IGES2DXF on our web site at:
http://www.imsrv.com

The free threading program and Cad-Cam-EDM-DRO special offers are at:
http://209.69.202.197/cadcamedmdro.html


Best Regards,

Fred Smith
IMService

imserv@...
Phone: 248-486-3600 or 800-386-1670
Fax:248-486-3698