Re: Automatic Tool Path Generation

From: Phil Orenstein (
Date: Tue Feb 10 1998 - 09:50:25 EET

Brent Stucker wrote:
> Bain is bad. However, I wonder how many people agree with Mark. I think
> that STL files can be as accurate as you want them to be as long as you
> make the triangles small enough. (You have to deal with big files then, but
> with today's fast computers that shouldn't be too much of a problem.) The
> simplicity of STL files makes them very likeable to me.
> Any other comments?


Stl files are as accurate as your underlyling surface or solid model and
dependent on the facet resolution that you set. I work in AutoCAD & MDT
and I've never experienced any trouble with Stl files. Its best to work
with a 'watertight' solid model and set a high resolution (many facets).

There have been some interesting articles in Modern Machine Shop on
machining from stl files. It seems that the major benefit is accurate
file translations from diverse CAD packages. Many people don't trust
IGES, but Stl is very dependable because it is simple and unabiguous and
doesn't carry along needless structural data, just the basic machinable
geometry of the part.

Don't get tricked by 'automatic'. Its basically a hype word. By
automatic they mean that their software uses the surface to directly
calculate toolpath data. You still have to supply speeds & feeds,
spacing, direction etc, etc. You just don't have to do the CAD geometry

In my experience I've found that the best approach is to use a CAD/CAM
package that incorporates a good solid modeler to create machinable
surfaces from which the toolpaths are 'automatically' derived.

                Phil Orenstein

For more information about the rp-ml, see

This archive was generated by hypermail 2.1.2 : Tue Jun 05 2001 - 22:44:52 EEST