Challenges and Choices in the Specification and Implementation of the STEP-NC AP-238 Standard

[+] Author and Article Information
Martin Hardwick

Department of Computer Science, RPI, Troy, NY 12180

David Loffredo

 STEP Tools, Inc., 14 First Street, Troy, NY 12180

J. Comput. Inf. Sci. Eng 7(3), 283-291 (Jul 10, 2007) (9 pages) doi:10.1115/1.2768090 History: Received August 21, 2006; Revised July 10, 2007

STEP-NC AP-238 is the result of a ten-year effort to replace the RS274D (ISO 6983) M and G code standard with a modern associative language that connects CAD design data to CAM process data. STEP-NC builds on previous work to develop a neutral data standard for CAD data and uses the modern geometric constructs of that standard to define device-independent tool paths, and CAM-independent volume removal features. This paper describes four key factors, or challenges, that had to be addressed to extend STEP-NC AP-238 functionality beyond that offered by other CNC standards. The four factors are difficulties inherent in all CAD/CAM integration projects and can be summarized as follows: the information complexity of geometry, the volume of attributes defined for manufacturing processes, the difficulties of integrating models that span CAD and CAM, and the requirement for easy implementation. We describe an advanced CNC application that uses these four factors and show how STEP-NC AP-238 enhances CNC machining and measurement.

Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 1

Some limitations of the RS274D Standard

Grahic Jump Location
Figure 2

STEP definitions for point and B-spline curve written in EXPRESS

Grahic Jump Location
Figure 3

EXPRESS-G description of the STEP-NC process model

Grahic Jump Location
Figure 4

Design to manufacturing pipelines

Grahic Jump Location
Figure 5

STEP AP-238 mapping for working step to operation relationship

Grahic Jump Location
Figure 6

New implementation architecture

Grahic Jump Location
Figure 7

Architecture of the tolerance application

Grahic Jump Location
Figure 8

(a) Toleranced part and probing operations, (b) colors for individual probe results and complete features, and (c) probing results for a particular hole feature




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In