Manufacturing is all about efficiencies. Discovering them. Implementing them. Profiting from them. And in the increasingly competitive transportation industry, better efficiency isn't just a goal--it's a prerequisite for survival.

Peterbilt Motors Company, a leading manufacturer of premium quality trucks for the over-the-road, construction, municipal and medium-duty markets, knows not only how to survive but to thrive in today’s challenging environment. Peterbilt, a division of PACCAR Inc, constantly develops and invests in ways to decrease time to market, improve quality, and reduce costs.

It was these objectives that led the company to develop its new aerodynamic Class 8 truck, the Model 387, using Pro/ENGINEER® . The Model 387 is the first full vehicle the Peterbilt team developed from the ground up using solid models. “As a result of this process, prototype, tool and development lead times for many parts were dramatically reduced,” says Bruce Lawyer, Peterbilt Assistant Chief Engineer. “Virtually every step—from visualization and clearance checks to drawing modifications— was enhanced thanks to Pro/ENGINEER. For instance, the design and styling of the Model 387’s premium-length hood was done completely electronically and released directly for production tools. This saved time and expense by eliminating costly verification models.”

One of the first challenges of reducing time to market involved the truck’s styling— development of the interior and exterior “show” surfaces. Prior to Pro/ENGINEER, we used 2D design tools and completed all proposal renderings in the traditional fashion, with hand sketches and tape lines. As with the development of previous vehicles, styling studies with “sight” models were done at scales ranging from 20% in clay, all the way up through full scale in tooling foam materials.

Most of the exterior surfaces— along with interior components such as the dash and other highly sculpted features—were also modeled by hand and adjusted per the styling group’s direction.

As the project progressed, the purchase of CDRS ™ (formerly Pro/DESIGNER®) drove the Model 387 further into the virtual realm by allowing the electronic design and manipulation of more complex surfaces. Initially, the team scanned scale models to produce point data. These data were in the form of a text file containing a grid of 3D points from the surface of the model and reformatted for Pro/E. The data were imported into Pro/E, where the surfaces were then created and verified to the full-scale models.

While design engineers created many of the Model 387’s surfaces in Pro/ENGINEER, they used CDRS to generate some of the more complex contours requiring more powerful tools. Since the complex surfaces were mathematically defined in the Pro/ENGINEER models as the master record, this process eliminated thousands of drawing sheets. Moreover, the company was so confident in the surface models that many production tools were cut right from the computer math data, saving time and money.

Through the success of the Model 387 program, Peterbilt was able to further improve the styling process. Designers are now able to scan the models electronically and import the resulting data into ImageWare, a third-party tool by SDRC that creates section curves from 3D points. The curves are then exported to CDRS and used to develop the required surfaces, which are then refined, rendered and evaluated using Pro/PHOTORENDER ™ .

Designers can make changes directly to the electronic model, such as apply textures and real-world backgrounds, and determine with confidence the viability of their changes. This significantly reduces the time to achieve a final surface. Once approved, a surface is then imported into Pro/ENGINEER for use by the design engineering groups.

Peterbilt engineers have found that, in addition to its intended application, Pro/SHEETMETAL ™ can be used in other innovative ways. During the Model 387 project, interior soft trim parts were created to match the complex contours of the new interior and converted to equivalent sheetmetal parts models. “These interior pieces could then be flattened to create pat-terns for drawings and tool lay-outs,” says Wade Walterscheid, lead design engineer of the Model 387 interior systems. “This helped reduce lead time for tool development and prototyping significantly. Without Pro/ENGINEER, these parts would have required the lengthy process of reverse engineering.”

Peterbilt designers used Pro/CABLING® , Pro/HARNESS® and Pro/DIAGRAM® to develop the electrical harnesses on the Model 387. Pro/CABLING made it possible for designers to route harnesses more quick-ly and efficiently, as well as automatically generate accurate cable lengths—critical for harness fabrication. This tool also made it easy to create assembly drawings in isometric views, which in turn made wiring installation easier for assembly line workers.

The team used Pro/DIAGRAM to created parametric connector tables and electrical schematics to describe the harnesses. In the previous environment, Peterbilt designers created the diagrams manually. This method sometimes produced discrepancies, which also had to be edited manually—quite a task considering that harnesses can have more than 100 breakouts (splits from the main harness). Pro/DIAGRAM also allowed the team to access connector symbols from a common library, improving drawing consistency as well as simplifying future modifications and new harness development.

Peterbilt engineers used Pro/PIPING ™ to map the route of the nylon tubing used to feed the Model 387’s air systems, including chassis and cab suspension as well as brakes. Pro/PIPING’s parametric nature shaved hours from the process. As with the electrical harnesses, team members were able to route the air lines through the virtual truck to produce routing lengths that needed little modification. In addition, they were able to create easy-to-update parametric schematics with Pro/DIAGRAM.

Peterbilt engineers working on the Model 387’s drivetrain used Pro/MECHANICA® to perform the initial engine mount analysis. With this tool, the team reduced the number of design iterations by more than half— saving many hours of manpower and shortening the design cycle for those parts.

With the help of Pro/PDM ™ , several Model 387 design groups were able to manage their design iterations and share them with other groups on the development team. This proved more efficient than managing data through shared directories, pre-venting data loss and duplication while also providing a secure repository for all released drawings and models. Since completing the Model 387 project, Peterbilt has continued to add PTC tools as it develops its next-generation products. For example, designers are now using 3DPAINT ™ to develop initial styling concepts and renderings for management review. Designers hope to reduce the iterations currently required, and further cut back on the number of required clay models. Peterbilt has also implemented Pro/INTRALINK ® —a more stable and robust data management tool than Pro/PDM—and will use it to manage all Pro/ENGINEER data.

Rob Franz is Engineering Systems Manager at Peterbilt Motors Co., responsible for CAD/CAE software evaluation, development, and implementation. Rob can be reached at rfranz@paccar.com. Brian Krieger is a CAD/CAM Specialist at Peterbilt, responsible for training as well as testing of hardware and software. Brian can be reached at bkrieger@paccar.com.