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| Fixture Builder Designs Process into
the Product |
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| CAD/CAM
Connectivity is key at InspectionAir |
Global
competitiveness is driving North American manufacturers to
produce accurate parts quickly. Software that communicates
effectively between CAD and CAM can help speed design time
and make the inspection process run more smoothly. |
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InspectionAir Gauge Ltd., Windsor, Ont., Canada has standardized
its check-fixture building business with a boost from SolidWorks/EdgeCAM
connectivity. The company has found that EdgeCAM Strategy
Manager halves programming and machining time and reduces
errors by three-fourths.
“The most important thing for us, as a manufacturer
of check fixtures and other tooling, is to standardize our
manufacturing if we are going to maintain our competitiveness
globally,” says Ray Sparnaay, general manager of InspectionAir
Gauge Ltd. “To do that, you have to gain control of
both the geometry creation and the programming process. Then
you standardize the ways the cutter paths are generated, for
both the tooling and the processing. We want the engineers
to design the process into the product. Once that is done,
the programming can be done on the shop floor, where it belongs.
“When you do that, you get consistent results,”
Sparnaay says. “But the two have to go hand in hand.
You can’t do it with just one, the processing in the
CAD, and not the other, the programming in the CAM.”
In a nutshell, that is how manufacturing keeps Sparnaay’s
60-employee shop from succumbing to the price pressures that
have dragged down so many other tooling shops.
Founded in 1963, InspectionAir has built a solid reputation
among its customers at General Motors, Ford, and DaimlerChrysler
for excellence in quality and aggressive management of the
design and building of its products. InspectionAir has three
Fadal vertical machining centers retrofitted with Numatix
CNC controls and a horizontal machining center with a Heidenhain
CNC. In addition to automatic toolchangers, each machine has
a tool carousel.
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Nearly all of InspectionAir’s
products are check fixtures for auto body assembly and structural
components; precision gauges for engine, transmission, and
aerospace components; precision gauges for engine, transmission,
and aerospace components. These jobs are essentially one-off,
with no repeats except for doors, quarter panels and fenders
that require right-hand and left-hand fixtures. The company
also offers digital camera-based 3D non-contact systems for
rapid scanning and inspection of surfaces.
Making the Connection
InspectionAir relies on EdgeCAM from Pathtrace Systems, Inc.,
Southfield, MI and SolidWorks, Concord, MA. With them as the
core of a tightly integrated flow of geometry from customers
through designers to machine tools, “CAM programming
and machining times have been halved,” reports Bill
Hissink, P.E., production manager.
The primary benefit of tying EdgeCAM to SolidWorks –
connectivity – shows up by digitally linking the machinists
to the design engineers. The previous CAM process was inefficient
at best. The programmers in the engineering department had
been regenerating SolidWorks files in the AutoCAD DXF format.
From these 2D drawings, layers and most of the other information
the programmer needed were stripped away. When the shop was
busy, those paper drawings caused a bottleneck.
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“The
operators needed that information, but the CAM system wouldn’t
handle it,” Hissink says. “So they had to recreate
it themselves. They had to visually check each drawing, feature
by feature, and make sure they pinpointed and programmed the
center point for each of dozens of holes. If a wrong hole
was picked into a series before machining, an under- or oversized
drill and tapping tool would be used on it.”
The old process made it too easy for the CAM operator to select
an incorrect point from the DXF file and drill a hole in the
wrong place. The operator also could easily misread a hole
diameter or depth from the paper drawing, which usually lay
on a workbench next to the machine tool.
This was instantly remedied by connectivity. Once a customer
job has been generated in SolidWorks at InspectionAir, the
model or assembly can be opened directly in EdgeCAM –
from within SolidWorks – with no need for translation.
What was in the SolidWorks file goes into EdgeCAM and the
CNC program. “Now the programmer lets EdgeCAM do all
this for him,” Hissink says. “EdgeCAM always know
where the center points are. For tedious tasks like picking
and grouping holes, EdgeCAM really won’t let you screw
up." |
“With SolidWorks,” he adds, “EdgeCAM automatically
makes sure the diameters are correct, how much stock to leave,
speeds and feeds, and so on. This means the guys on the shop
floor don’t have to manipulate geometry anymore to make
a program. That should be the designer’s job.”
Designing the Process
Sparnaay and Hissink are moving all but the most complicated
CAM programming from the engineers in the usually overloaded
design department to the machine tool operators. In particular,
InspectionAir is standardizing the way it machines fixture
base plates, which have dozens of different positioning and
mounting holes.
Every fixture gets a standard base because customers frequently
move fixtures from one press line to another. Fixture bases
(steel plates machined flat and square) are the most repetitive
part of InspectionAir’s work. Dowel holes without threads
are drilled to accommodate pins used to position a fixture
on a machine tool’s bed.
“Now we know exactly where all the features are in 3D
space,” Hissink says. “That really simplifies
and speeds up machine-tool programming.” The drilling,
boring, reaming, tapping, and countersinking of each set of
holes are controlled with Strategy Manager. With automation
built using Strategy Manager, a single toolpath is created
for all the machining operations on the base plate. No matter
how many holes and variations are needed, they are now all
in one CNC program controlled by Strategy Manager for consistency.
“We plan to use the capabilities of the new 3D version
of Strategy Manager in EdgeCAM Version 9.0,” Hissink
says. “That will enable us to complete the transition
to shop-floor programming. We expect big cuts in 3D programming
time, too.”
Threaded holes are required to mount the fixtures components
onto the base. InspectionAir also has specific threaded-hole
patterns for attaching small gauging components. Placement
and alignment of the holes is essential to the fixture’s
accuracy and repeatability.
The possibilities for error in the old system were controlled
to some degree by generating a new CNC program for each different
hole diameter. As many as 15 toolpaths would be created for
each base. “The average base had five or six different
diameter dowel holes,” Hissink says. “That meant
as many as 10 programs, some with multiple toolpaths. Each
program had dozen or more holes with three machining stages
(drill or bore, ream and tap, countersink) and required 15
to 20 tools per program.”
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“By designing the process into the product, consistency
reduces our costs and maintains or improves our competitiveness,”
says Sparnaay. “Using SolidWorks and EdgeCAM together
lets us do more with the hours that we have.”
Programming errors – primarily due to misinterpreting
drawings – “have dropped by more than three-fourths,”
Hissink says. Largely thanks to EdgeCAM’s built-in feature
recognition, that shows up in sharply reduced rework and scrap.
Those savings go straight to the bottom line.
“SolidWorks allows us to capture in the design process
the reusable parts of the engineering and solid geometry,”
Sparnaay says. “Programming is being tied right to the
3D solid geometry so what the programmer sees is the finished
product. It would be fair to say that SolidWorks has revolutionized
our design process.
“The engineers,” Sparnaay continues, “will
put the surfaces on the products as these come from the customers.
No more do guys from engineering go to the shop floor with
a handful of paper drawings and ask the operator to ‘picture
how the part looks in this (2D) view. Now picture how it looks
in this other (2D) view.” |
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“We want to migrate the product engineering to the next
level with SolidWorks and migrate the programming to the shop
floor with EdgeCAM,” he says. “This works because
EdgeCAM always knows what the SolidWorks geometry is. You
can flowchart the programming of each job with Strategy Manager.
It is the key to our standardization which, in turn, is the
way we have to run the business if we are going to stay competitive.”
“The machinists know which programs they need at any
given time, when jobs are reprioritized,” Hissink says.
“The operators can generate the programs they need on
the fly rather than waiting for the designers to do it for
them. The designers have no way of doing that.”
After the transition, two of InspectionAir’s 12 designers
will be freed from programming tasks. “Their skills
and time are needed on designing new jobs, not doing something
the operators could be doing,” Hissink says.
Extra Advantages
The automation routines also access the EdgeCAM Tool Database,
which mirrors the tools available in the machining center’s
automatic tool changer. This simplifies and automates the
selection of the proper tooling for each job. As many as a
hundred different drills, reamers, taps, counterbores, and
countersinks may be required for a fixture base plate.
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The EdgeCAM Tool Store database at InspectionAir is now populated
with more than 100 tools. As a result, “Strategy Manager
is taking over most of the 2D drilling,” Hissink says.
“About the only programming error we see now,”
he says, “is putting the wrong tool in a pocket of an
automatic tool changer.”
The connectivity benefits show up externally as well. Suppliers
of large weldments to InspectionAir also use SolidWorks, so
InspectionAir can exchange files directly with them. With
that, another opportunity for misreading or misinterpreting
drawings is eliminated.
Customers also needed “much better visualizations of
what they were getting and how the fixture would work than
what they could get from 2D drawings,” Hissink says.
“They pushed us to modernize and streamline our methods.
So did the competition, which gets tougher and tougher all
the time.” |
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