One generation ago—about 25 years ago, that is—industrial metalworking was in the midst of a transition. Where machine tool motion had traditionally been governed either mechanically or by human oversight, a great many shops at that time had begun to define this motion instead using coded programs. These programs were written for machine tool controls that awaited only the proper instructions to send their machines’ axes through any sequence of moves. One generation ago, NC machining became a mature and accepted technology.

In 2000, there are still plenty of people in the metalworking industry who remember the time when essentially all of metalworking was manual or mechanical. However, a larger group of metalworking professionals has no personal memory of the day when NC machining did not play a major role in the industry. And today, both groups are carrying forward another transition—one that involves harnessing the potential of today’s cheap and powerful computer technology.

This is not to say that the transitions break along convenient generational lines. In many shops, the move to NC is still ongoing. And as for the next move forward, one could argue that it began many years ago. In fact, it may have begun the day another “C” was added to the abbreviation. “Numerical control” is now something of an antiquated term. Today, we speak of computer numerical control. And the defining transition today is a move toward processes in which computer technology lets barriers to information flow fall away.

Here are just some of the trends that seem destined to gather momentum:

1. CNC becoming computer “network” control. CNC machines no longer have to be islands on the shop floor, remote from communication. Some CNCs available today are capable of two-way communication across a network. As a result, numerous CNC machines can be monitored—even operated—from a common, central location.

   A "Significant Event" At Cessna - Remote CNC monitoring allows machine tools at an aircraft manufacturing facility to be used more productively. See also the column written by Mark Albert, the article's author, about this same application.

2. Measurement and quality integrated throughout the process. Inspection no longer has to occur after-the-fact and apart from the process. Closed-loop measurement systems make it possible for a process to inspect its own work and compensate automatically if a variation is detected.

   Consider Closing the Loop - In this shop, parts coming off of a standard CNC lathe are inspected by an automated system networked to the CNC. When the trend of the inspection data changes, the system adjusts CNC offsets to compensate. Thus the system can be relied on to machine large batches consistently without human intervention.
   
   The Shop With A Nervous System - Instead of preventing thermal growth and contraction in large workpieces, this shop devised a system for precisely compensating for the thermal effects. The system involves monitoring temperature at the machine tool, and post-processing the CNC program on the fly to adjust for dimensional changes in real time.

3. Traditional machining speed limits taken away. In many processes, the CNC’s ability to control axis position defines how fast the machine can feed. But with faster processing, the new speed limit may be based on the harmonic characteristics of the cut.

   Boeing's One Part Harmony - At this manufacturing facility for military aircraft, the most productive speed for milling aluminum is not necessarily the highest speed available. Instead, the most productive speed for a given application precisely favors the chatter conditions of the cut.

4. Tighter integration between shops and suppliers. Computer technology now makes it possible even for small shops to take delivery of tools and other supplies on a just-in-time basis. It can also permit shops to receive remote troubleshooting for their CNC machines.

   Long-Distance CNC Service - By allowing the service technician to troubleshoot a CNC machine tool without making a trip to the shop, an "open" CNC can reduce the time and expense required for service calls.
   
   Own No Tool Before Its Time - The role of effective information technology is such a "given" in this inventory management success story, the article doesn't discuss it directly. Instead, this article focuses on a relationship the technology makes possible. By inviting its cutting tool supplier to open a branch office on its shop floor, this job shop achieved truly just-in-time tool delivery.

5. The use of the Web as a customer-service tool. Suppliers to machine shops are already using the Web in this way. Now, some contract shops are following suit.

   Connecting With Customers - This contract shop uses the Internet to give customers direct access to the shop's own management system. The result is improved customer service, achieved practically effortlessly. Customers get instantaneous information on job status, projected delivery date, and quantity on hand.

6. Expanded services from metalworking trade magazines. Okay, this one is a little self-serving. However, the broad trend of improved information flow also affects those of us who serve the metalworking industry through publishing. In the past, the best that publishers could do for their readers was to mail them a magazine every month and hope the readers found information in it they could use. Now, thanks to the Internet, the same magazine can become a reference tool that any metalworking professional can consult on an as-needed basis.

Modern Machine Shop’s Web site lets readers find more information about the technologies, products or suppliers they see mentioned in print. As a result, the magazine and Web site together carry readers farther today in their search for information than the magazine alone ever could. MMS