shaping the future of metrology - Brown & Sharpe

Paramount, California
Gantry CMM Helps Aerospace
Contractor Keep Pace
Today, there are two constants in the
evolving world of aerospace manufacturing—tight
design tolerances and
even tighter delivery schedules. At Aircraft
Engineering Corporation, staying competitive
in this tough business means
taking advantage of the opportunities
that those two challenges offer a seasoned
contractor.
AEC is a versatile, Small Disadvantaged
Business providing engineering,
design, numerical control programming,
and fabrication support for major assemblies,
sub-component assemblies, and
tooling to the country’s advanced commercial,
military, and space programs.
For the past 38 years, AEC has developed
and refined an expertise in tool design,
machining, welding, composite fabrication,
bonding, and structural assembly in
both prototype and production atmospheres.The
company also supports installations
of end item assemblies and large
assembly tools, giving customers turnkey
support from a single source.
AEC’s extensive operations are housed
in seven buildings in Paramount, CA, with
more than 160,000 square feet of manufacturing
space. It’s one of the largest and
most advanced facilities of its kind.
The company’s commitment to ontime,
on-spec production rests on the use
of modern production equipment and
the experienced personnel to operate it.
For example, in the composite fabrication
department, a computer controlled
autoclave, a vacuum forming machine, a
large walk-in freezer for the storage of
composite materials, and curing ovens
22 mfg. Shaping the Future of Metrology
assure precision manufacturing operations.
AEC’s welding department fabricates
complex flight hardware, ground
support equipment, electro-mechanical,
and hydraulic systems.The tooling department
is equipped to produce plaster
master patterns, fiberglass and carbon
fiber lay-up for tooling and production
parts, graphite composite tooling, assem-
bly jigs and fixtures, templates, form
dies, and router fixtures. AEC’s machined
parts/assembly department supports the
needs of the fabrication and tooling departments,
as well as customers’ needs
for machine/assembly work. Coordinating
this equipment to meet production
schedules is one of the secrets of the
company’s success.
Some of the largest aerospace components manufactured in the United States are inspected on this
Brown & Sharpe DEA DELTA gantry CMM at Aircraft Engineering Corporation.
Keeping Pace
With Customer Needs
Using advanced software
systems, AEC has successfully
combined computer aided
design with manufacturing
and inspection operations to
accommodate last-minute
customer design changes.
One of the ways that AEC
keeps up with the demand for
tighter delivery schedules,
even with the last-minute design
changes that are frequently
part of new programs, is through
the integration of computer aided design
with the manufacturing and inspection
operation.
Recently, the company added eight
IBM RISC 6000 workstations running
CATIA ® Version 4.1.7/FR4.1.7 software
developed by Dassault Systèmes, and four
Pentium ® Pro workstations operating Unigraphics
II design and manufacturing
software.These software systems allow
AEC engineers to use the customer’s encrypted
design data to produce a 3D
solid model tool design based on the
customer’s requirements.
Another recent acquisition is a DELTA
gantry-type coordinate measuring machine
from Brown & Sharpe DEA.The
DELTA CMM at AEC has a measuring envelope
of 200" (X), 100" (Y), and 72" (Z)
and can accommodate virtually any part
or assembly manufactured by AEC.The
machine, one of the largest on the West
Coast, has undergone testing and qualification
at AEC and is certified to Advanced
Technology Assembly specifications.
This large CMM is being used primarily
to prove the accuracy of CNC machining.
In a typical application, the CA-
TIA software is used to create inspection
points based on the information from
the part model.
These inspection points are used to program
the DELTA to determine if the part
conforms to machining specifications.
CAD Link Reduces
Inspection Time
The DELTA is equipped with PC-
DMIS for WINDOWS geometric measurement
software. A special feature of PC-
DMIS for WINDOWS allows operators to
use the accuracy of original design data
to create off-line inspection programs
with graphical part models and probe
path simulations. At AEC, PC-DMIS for
WINDOWS downloads 3D part models
from the CATIA system and creates a
graphical representation of the part.The
CMM operator simply clicks on any surface
or feature of the model to create a
DCC inspection program. Inspection results
can be uploaded directly to the CA-
TIA system by IGES and DMIS links.
AEC also uses the optional Curves and
Surfaces module which imports freeform
3D models from the CATIA system
and automatically extracts mathematical
surface nominals and direction vectors.
When the operator clicks on the surface
to be inspected, Curves and Surfaces drives
the CMM along the orthogonal surface
vectors and collects measurement
data.That data is compared to the CAD
nominals, and the “fit” of the surface is
accurately determined regardless of its
complexity.When the user clicks on the
program’s interactive graphic model of
the part, Curves and Surfaces provides the
nominal and actual point deviation.The
program also automatically displays the
nominal tolerance band over the actual
data curve providing clarity of the conformance
of a surface to its nominal model.
“One of the reasons AEC purchased
the DELTA was to allow the inspection
program to keep pace with our new
high-speed three, four, and five axis machines,”
according to Jack Peacock, AEC
Quality Assurance Manager.
Some of the smaller parts checked
can be inspected in as little as three minutes.The
larger assemblies and tooling,
perhaps having 400 to 500 points to
check, take an hour to two hours.
“Without the DELTA, that kind of inspection
would take us up to a day,” he
continued at AEC page 49
mfg. The Brown & Sharpe Publication of Precision Manufacturing
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