Route to 3D: Solid modeling provides a better way to design tanker trailers

Remtec Inc., a subsidiary of Remcor Inc., designs and manufactures tanker trailers for petroleum products. These are the big tanks you see delivering gasoline to service stations but they also transport other petroleum products, such as asphalt. While from the outside it may look like one big tank, on the inside, it is divided into four to six separate compartments.

Remtec is the main petroleum tanker trailer manufacturer in Quebec, based in Chambly, but its parent company owns a similar business in British Columbia as well as two in the U.S. (in Nebraska and South Carolina). According to Remtec’s director of research and development, André Bourgault, the market for these tanker trailers is not as large as for other truck trailers, so competition is strong. Customers expect faster and faster delivery times, so "the ability to design and assemble a trailer fast is a competitive advantage," he says.

In addition to the pressure to deliver tankers quickly, Remtec faces other challenges in the design of its products. First, these tanker trailers consist of many parts (some designed in house, others provided by suppliers) and it’s necessary to keep track of everything with an accurate bill of material (BOM). Second, because Remtec’s tankers are oval rather than round (to lower the center of gravity and prevent rolling over), designers must work with complex shapes, in particular where the front and back "heads" of the tanker interface with the main portion of the body. Third, the majority of these designs involve sheet metal, making the creation of accurate flat pattern drawings crucial.

Remtec’s previous CAD system was 2D AutoCAD. It claimed it was difficult to do this work in 2D, especially when creating the complex surfaces of the heads as well as keeping BOMs up to date. It was necessary to create a new BOM each time a design variation was made. This was also true for the sheet metal flat patterns. With AutoCAD it was also more difficult to detect interferences prior to having parts made. Errors that were detected on the shop floor delayed delivery and increased development costs.

Realizing that 3D modeling could address these issues, Remtec evaluated a number of solid modelers, and the first couple was ruled out due to cost. SolidWorks and Solid Edge were put through a thorough benchmarking process that led to the selection of Solid Edge. "The Solid Edge guys took better care of us and we were satisfied with the capabilities of the software," Bourgault explains. "Also, Solid Edge is easy to learn and use."

WORKING QUICKLY, VIRTUALLY
Remtec now builds virtual, complete tanker assemblies in Solid Edge, parameterizing the model so that it can be changed quickly to meet a customer’s needs. "We have several models and depending on what the customer wants, we simply modify variables such as length, height, width, number of compartments and so on," Bourgault says. "With parametric modeling, this happens much quicker than it used to with AutoCAD." Once a parametric model is done, it takes Remtec about half as much time as it did in the past to tailor a design to a customer’s specifications.

One very important benefit of Solid Edge is its sheet metal modeling environment. Once a sheet metal part is designed, the flat pattern is generated automatically. "With 2D this was very time consuming, but with Solid Edge it is just a mouse click," Bourgault notes. A BOM is also just a mouse click away once the model is finished, saving the company the 12 to 15 hours that used to be required to generate a single BOM from drawings. The BOMs are also more complete because Solid Edge counts all the small items such as fittings, washers and bolts that used to be omitted in the past.

When a customer asks for something unique and a new design is required, Remtec no longer builds a mockup. Remtec is confident about doing this because the company is able to detect interferences in the software. The accuracy of the designs created in Solid Edge has made it possible to design and build a first production unit 20 percent faster than before. And because there are fewer errors and scrapped parts, the company saves money on development costs.

Solid Edge brings other advantages as well. Production drawings are now easier for shop personnel to understand. "They are clearer than before because now we can do exploded views and 3D views. The guys in the shop all like that and there is less error in assembly now," Bourgault says.

"Another advantage of Solid Edge is that designers like it. It is a lot more motivating to work in 3D." Remtec also sends its 3D images to its customers for design reviews. The customers find the 3D images much easier to interpret than 2D drawings.

John Smith is a technical writer for Siemens PLM. (c)2010 Siemens PLM Software Inc. Reprinted with permission.