FOR IMMEDIATE RELEASE:             Mark Bello
Sept. 29, 1994                     (301) 975-3776

                                   TN-5991

              BOEING TAKES MEASURE OF NIST QUICK-TEST METHOD


     Inspection and process-control improvements achievable with
a testing tool developed at the National Institute of Standards
and Technology recently prompted the Boeing Commercial Airplane
Group to enter into its first-ever cooperative research and
development agreement with a federal laboratory.

     NIST and the Seattle-based maker of passenger jets, the
largest Boeing Co. unit, will focus initially on NIST's easy-to-
use system for regularly checking the performance of coordinate
measuring machines, or CMMs.  Potentially, the technology could
be applied to all of the some 130 CMMs installed in six of
Boeing's nine divisions.  There, the automated measuring machines
are used to inspect the dimensions of parts that the company
makes or buys from suppliers.

     Called the NIST interim testing artifact, the modular,
lightweight system consists of a pair of inexpensive, calibrated
ball bars (two steel spheres connected by a steel bar) that are
kinematically mounted on rotatable aluminum arms.  The base is
screwed into inserts on a CMM table, and the baton-like ball bars
are rotated from one indexed position to another.  At each
position, the CMM takes a series of preprogrammed measurements,
and the results are compared with known values.

     To ensure measurement accuracy, Boeing currently calibrates
its CMMs periodically, according to the performance history of
each unit.  This is a costly process that can take from four days
to two weeks.  In between calibrations, the NIST interim testing
artifact can greatly enhance a CMM operator's ability to quickly
ascertain the performance of the machine and its subsystems.

     "The data-collection and -analysis process is so quick--a
complete system check-up can be accomplished in less than half an
hour--that weekly performance evaluations are practical,"
explains Edward Sergoyan, an engineer for BCAG Operations
Technology, the commercial unit's research and development arm.

     The greatest virtue of the artifact, however, may be its
thoroughness.  It includes all CMM subsystems, which usually are
calibrated separately, into one measurement profile.  "The way
the system is configured allows you to uncover subtle problems
that might not be identifiable during separate calibrations,"
Sergoyan says.  The interim testing artifact provides such a
reliable performance check, he adds, that it could allow Boeing
to recertify its CMMs on an as-needed basis, rather than
according to a predetermined schedule.

     During initial research testing of a prototype unit at a
Boeing facility, the artifact's practical value quickly became
apparent.  While demonstrating their innovation, Steven Phillips,
NIST CMM program manager, and his team first discovered
measurement errors on a CMM and then pinpointed the cause--a
faulty mechanism preventing the measurement probe head from
locking into place.  Currently, a pneumatically controlled
version of the artifact--adaptable for use on various types and
sizes of CMMs--is being evaluated at three Boeing fabrication
facilities.

     Soon a fully automated, computer-integrated version will
undergo trials at Boeing.  NIST also is supplying the company
with calibrated ball bars from 300 millimeters to 1.5 meters long
so that the system can be used to evaluate a range of CMMs.

     Boeing's interest in the NIST testing artifact stems from
the measurement intensiveness of aircraft manufacturing and the
company's increasing reliance on CMMs for inspection tasks.
According to Sergoyan, about 30 percent of the 4 million parts
that make up a Boeing 747 passenger jet are inspected on CMMs.
Boeing's newest jet, the 777, contains somewhat fewer parts, but,
he says, 70 to 80 percent of those parts undergo CMM inspection.

     While NIST and its partners continue to work on more
advanced prototypes of the interim testing artifact, several
Boeing divisions already are convinced of the technology's
utility.  They placed orders for commercial versions of the
pneumatic system, made by Giddings and Lewis Measurement Systems,
Dayton, Ohio.

     After applying an early prototype of the testing artifact in
a project to develop adaptive methods to enhance CMM accuracy (an
effort co-funded by NIST's Advanced Technology Program), Giddings
and Lewis chose to commercialize the technology.  The first
products based on the NIST design recently have been released.

     Meanwhile, Boeing is exploring applications of the testing
artifact in manufacturing process control.  Increasingly,
manufacturers are incorporating measurement probes into their
machine tools, enabling in-process inspection of part dimensions.
But problems can arise.  For example, a machine's frame may be
out of square or its scale may be miscalibrated, resulting in
inaccurate measurements that easily escape notice.

     As it does for CMMs, the interim testing artifact offers an
independent means of assessing the performance of measurement
equipment on machine tools.

     Encouraged by the prospects for the CMM-focused
collaboration, Sergoyan describes Boeing's new relationship with
NIST as a "good union," good enough to warrant exploring
cooperative work in other manufacturing technology areas.

     As a non-regulatory agency of the Commerce Department's
Technology Administration, NIST promotes U.S. economic growth by
working with industry to develop and apply technology,
measurements and standards.

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