The Next Step

A proposed extension to the ISO standard offers big benefits to NC machining.

Last November Martin Hardwick presented an innovation that promises to change the economics of NC machining forever. His firm, STEP Tools Inc., Troy, N.Y., held the first demonstration of STEP NC, a proposed extension of the international standard known as the Standard for the Exchange of Product Model Data (STEP). STEP was developed by the International Organization for Standardization, which received a mandate from the United Nations to develop one extensible, comprehensive standard for product data. The overall standard, like its more primitive predecessor, IGES (Initial Graphics Exchange Specification), deals with the leading problem of engineering collaboration data incompatibility. The NC extension parallels STEP's overall ability to seamlessly facilitate data flow in B2B situations, but at the CAD-to-CAM level between design and manufacturing. Those savings complement each other synergistically. Consider Hardwick's example of an OEM that wants to reduce the time needed between the design of a 3-D model and its manufacture. "To do that today, the 3-D model has to be converted into a drawing before it can be sent to manufacturing. With STEP NC, they'll simply send the geometry as a 3-D model." Hardwick says that alone could result in time savings of 75%. The demonstration, which was viewed by industry observers including standards-making organizations, machine-tool builders, software vendors, and control makers, was a complete art-to-part process via STEP NC. "First we designed the part using Cadkey software and stored the resulting geometry in the STEP format," Hardwick explains. He says other CAD systems such as Unigraphics, Catia, or AutoCAD would have been equally appropriate. "Then the geometry went into an advanced process-planning system retrofitted for STEP NC. Output from the process-planning system was then fed to the controller of a Bridgeport [machine tool] that made the part." Hardwick emphasizes that the process-planning step is greatly simplified, paring 35% of the time normally required for that process. "In addition, the machine tools become safer, faster, and more adaptable. They become safer because, for example, the machine tool will know exactly where the geometry of the part is and will avoid damaging it. The machine tool also will know where the fixtures are and prevent their destruction. In addition, the machine will do much of the safety checking done manually today. And the increased flexibility means last minute changes will more easily be accommodated." Hardwick says the benefit comes from the controller having all the information about what it's supposed to make. "STEP NC also will make it easier to take a part program that was developed for one machine and move it to another machine." For Hardwick, identifying the significance to manufacturing of collaboration predates the Internet's B2B activities. He first saw the need for facilitating collaboration in 1988 at Rensselaer Polytechnic Institute (RPI), Troy, N.Y., where he is a professor of computer science. (He also is director of RPI's Laboratory for Industrial Information Infrastructure.) "I got involved with General Electric on something called DICE, which was the DARPA Initiative for Concurrent Engineering. That was a time when the design and manufacturing cycles in the U.S. were far too long compared with what they were in Japan. Detroit was in trouble and [automakers] were searching for ways to reduce cycle time via concurrent engineering. "Our team very quickly concluded that facilitating collaboration meant that people had to have better tools to understand each other's data." Likewise, with STEP NC machine tool controls better understand and fulfill the intent of the part designer. Hardwick founded STEP Tools in 1991 with the business mission of developing STEP translators for major CAD/CAM vendors and providing STEP translator services, including consulting. His STEP NC demonstration was the outcome of a $2 million Advanced Technology Program (ATP) Award in 1999 from the National Institute of Standards and Technology. Part of the company's motivation for ATP participation is the preparation the program provides for the new wave of translators and services that STEP NC will require. The company's STEP NC revenue will come from the license fees provided by participating CAD/ CAM and machine control vendors and from services and consultation. Technically speaking, STEP NC is now being balloted to become a draft international standard -- which means that all the major industrial countries are now in the process of voting as to whether they want to accept or revise the proposed standard, says Hardwick. In the U.S. the American National Standards Institute will cast the vote. He predicts STEP NC will pass its ballot and will become an official draft international standard in May. He expects it to become a full international standard in 18 months.

Hide comments

Comments

  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Publish