Fixture builder designs process into the product: CAD/CAM connectivity is key at InspectionAir.
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 CAD, and not the other, the programming in 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.
Nearly all of InspectionAir's products are check fixtures for auto body assembly and structural components; precision gages 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, EE., 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.
"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 knows 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 gaging 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 tapped holes and three or four different diameter dowel holes" Hissink says. "That meant as many as 10 programs, some with multiple toolpaths. Each program had a dozen or more holes with three machining stages (drill or bore, ream and tap, countersink) and required 15 to 20 tools per program."
"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 parts looks in this [2D] view. Now picture how is looks in this other [2D] view.'
"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.
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.
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." Pathtraee Inc., www.rsleads.eom/502tp-242
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|Publication:||Tooling & Production|
|Date:||Feb 1, 2005|
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