Solid Edge used to design innovative sewing and embroidery system for the world market
Solid Edge with synchronous technology serves as the digital development platform for Bernina’s next-generation equipment
“Nowadays, a sewing machine is a complex, high-tech product that combines precision mechanical, electrical and electronic components, as well as software, in a confined space,” says Gérard Durville, Bernina International AG’s development and design director for 10+ years. A pioneer since 1893, the Steckborn-based company is contributing to this trend. Besides Toblerone, Swatch and Rolex, Bernina is one of Switzerland’s premium brands and is among the global leaders in providing quality and precision in its sector.
The company, owned by Hanspeter Ueltschi, the founder’s great-grandson, employs some 1,100 staffers worldwide. About 300 of them are working in Steckborn. Target groups for Bernina’s products include quality-conscious homemakers and discriminating hobby-sewers.
State-of-the-art technology in a confined space
By the end of 2008, Bernina put the model 830 on the market – a sewing and embroidery system featuring exemplary functionality and quality. To do so, the company engaged a 50-member development team, comprising engineers from software development through quality assurance and supported by external personnel, as necessary. The team designed a platform for the company’s new generation of sewing machines. The result is a product line that is ergonomically exceptional, features touch-screen driven operations and yields significant new automation capabilities for its users.
“Recently, we intended to put a new model on the market every year,” says Durville. The company achieved this goal and continues to do so by adopting a platform strategy that promotes extensive same part usage, with the basis for that work performed by the company’s mechanical design department.
In 1995, Bernina was one of the first companies in Switzerland to implement Solid Edge® software for the Windows operating system. Solid Edge is a user-friendly, 3D computer-aided design (CAD) system. Today, the company leverages 17 licenses using the powerful Solid Edge with synchronous technology. “We are only able to handle such an amount of precision mechanics in a confined space via a 3D environment,” says Durville. “It is unthinkable to design such things in 2D.”
New flagship: Bernina 830
The advantages yielded by Solid Edge are especially recognizable in the Bernina 830, the company’s top model. “It is already the third product that has been entirely defined in Solid Edge,” says Alain Capt, CAD coordinator at Bernina. The entire 3D assembly model consists of 1,500 highly detailed parts that consume about 500 megabytes of disc space. Durville adds, “When handling such complex assemblies, short waiting times for the users determine our efficiency.” By using an advanced assembly CAD technology within Solid Edge, loading only the required sections enables shorter access times. However, all part property information within the assembly is available at any time. Complete “digital mockups” are permeable and automated collision controls enable the needed design to be effectively developed in a highly confined space. Collision and motion analyses of assemblies give additional support. “Via Excel entries, we address variables in Solid Edge and examine the various motion sequences of our products,” says Capt.
The new top model includes a main drive that has to generate enough power to be able to sew more than 30 layers of fabric at a speed of up to 1,100 stitches per minute. It also has to be capable of cutting leather or balsa wood. No less than 16 stepper motors enable a scope of functionality like the transversal transport in 360-degree directional sewing, an automated needle threader, fabric transportation from top to bottom, as well as an automated swing-out, rotary hook. Swiss precision is measured in micrometers and can be seen when sewing a zig-zag pattern, such as a Christmas tree, where the sewing needle must end exactly where it started.
Interface to FEM analyses
During equipment operations, there can be significant forces on a number of components, making correct dimensioning enormously important. An interface between Solid Edge and a finite element solution eases structural analyses. With Dynamic Designer, an add-on product that is embedded inside Solid Edge, parts are optimized to handle accelerating forces and vibrations. To analyze the environment for the main drive and electronic parts, thermal analyses are run in order to ensure precision and longevity. Here, the machine’s center chassis plays an important role. This aluminum die cast part has to comply with stability, accuracy, weight, and vibration specifications. At the same time, it has to be designed to be easily manufactured. Durville notes that Solid Edge meets high modeling requirements, explaining: “In view of functionality for freeform surfaces, Solid Edge definitely plays in the same league as other, more costly systems. As we are continually demonstrating the power of Solid Edge with synchronous technology, we are hopeful that more of our suppliers and external designers will convert to this highly productive, easy-to-use tool.”
Hub for suppliers
Solid Edge establishes the digital data linchpin for the globally distributed manufacturing of various sinter, stamping and die parts. More than 350 tools are designed using the 3D models created with Solid Edge. Suppliers get the information as data exchange (DXF) files, which are exported directly from Solid Edge. Based on the 3D models, cost-calculation software is employed to evaluate the costs, especially of die cast parts. After entering parameters like overall size, wall thickness, weight, number of surfaces or number of slides, the software proposes a machine for the manufacturing process and calculates estimated tool and part costs. This information is very important in defining and optimizing target prices in advance.
Competitive edge secured: synchronous technology
Bernina now uses Solid Edge with synchronous technology, following a qualified implementation of the software by Siemens’ solution partner, Quadrix AG. Synchronous technology supports conventional, dimension-based or parametric working methods. It enables a user to specifically select 3D elements and make real-time modifications to them directly in the most convenient manner. “Especially during the concept stage, Solid Edge with synchronous technology is a wonderful tool for experimentation and new ideas,” says Capt. “But also in regard to changes, for example, for foreign parts adjustment, it offers significant advantages.” Gerhard Eimer, chief executive officer at Quadrix AG, adds, “Being a pioneer, Bernina develops innovative products with innovative tools. We engage the full functionality of Solid Edge to optimum advantage.”
Capt notes that designers are highly productive in designing sheet metal parts using synchronous technology. They are designing far faster than was possible with the previous approach and find the software substantially easier to use. With the numerous productivity gains and shorter design times enabled by Solid Edge, Bernina has established a solid foundation for future innovation and a stronger competitive advantage.