Customer References - LeicaSOLID OPTICSEntering the World of 3D DesignAttractive design and advanced engineering methods play an important role in product development - even if the products are classics. Well aware of this and of its own standing as one of Germany's most successful manufacturers of optical equipment, the Leica Camera Group set out to steal a lead on the industry, this time in product development. Leica opted for 3D CAD/CAM. Written by Ulrich Sendler in June '94, translated by Siegmar Siegel It was eighty years ago that the first 35-mm camera saw the light of the world - and recorded it on film. Superb precision engineering and an optical system reflecting nothing so clearly as the genius of its inventor were the secrets behind the new product. In the age of computers and computer aided design, this camera is still sought as a craftsman's tool and as a collectable by amateurs and professionals alike.
The headquarters of the Leica Camera Group are in the town of Solms, near Wetzlar in Germany. As in its earliest days, the company recognizes the importance of superior-quality metal parts and lenses as a mainstay of the success enjoyed by its cameras, projectors, magnifying systems, binoculars and telescopes over the decades. In recent years, the company has radically reviewed its development and manufacturing processes, with the result that it now holds a pole position among CAD/CAM users. Drawing boards were ousted by 2D CAD stations in the late eighties, and early 1994 saw the triumphant beginnings of 3D solid modeling. The skeptical opinion voiced by some designers and draftsmen was not the only stumbling block in the early days of CAD. Alfred Hengst, Head of Development/Design in Solms (Fig. 2), readily appreciated that the move from drawing board to drawing screen amounted to no more than a vital first step. It remained difficult to predict just what the future held in store.
In 1989, the company brought in external consultants to assist in the next major decision. Above and beyond choosing a vendor, Leica was intent on formulating a general contract with its software supplier that would minimize the company's risk. This objective was achieved. No initial productivity dipManagement finally opted for PE/ME10 from Hewlett-Packard, and the first seven workstations were installed. Progress was faster and better than expected. The first ten designers were trained they immediately discarded the old familiar work patterns and embraced the new approach. From that point on, they used their computer screens with equal eagerness both for initial drafting and for detail work. As Alfred Hengst recalls, "To our surprise, the dip that everyone had warned us to expect - productivity falling off in the middle of changeover - simply did not materialize. The system was easy to use and had a very logical structure. Our designers were motivated to an amazing degree, and still are. The worst skeptics, who had threatened to leave the company if their drawing boards were taken away, are now among the most convinced adherents of CAD." The Leica Camera Group now operates about thirty PE/ME10 stations. In-house developers have created so many custom macros and add-ons that the drafting, designing and drawing functions leave absolutely nothing to be desired. One rule was imposed at Solms, however, and rigorously applied: no changes to the user interface. The standard is strictly retained, not least because avoiding changes in the user interface imply costly adaptation when new versions of the software come along. The next step soon followed. In October 1990, the company was installing DMS. The Data Management System is another HP product, the forerunner to PE/Workmanager. Even then, the company had set its sights far beyond the mere practical management of engineering drawings. A project team was set up and endowed with considerable executive powers. Its job was to formulate the hopes cherished by the various departments for a solution of this nature. The team soon reported that reality would fall short of these expectations. The effort involved in customizing standard software to the company's specific needs is far in excess of that needed to adapt the CAD software itself. Clearly, it would be necessary to alter the user interface and add custom macros. PE/ME10 ran virtually as a standard system, but this would not be the case with DMS. Three test runs were conducted with the aim of assessing the as-installed functionality. The practical experience gained in this way was incorporated in an overall system: within a matter of weeks, DMS too enjoyed the same level of acceptance previously afforded to PE/ME10. DMS fulfilled its purpose so efficiently that only one month into productive usage management decided to dispense with parallel data backups on the local workstations. From then on, backups were stored only on the network server. Double backups rendered superfluousThe application employs the PE/ME10 file structuring function to directly map the parts structure commonly used by Leica. The BOMSs based on this structure are always up to date. Organizing release procedures and access permissions is part of the solution, which is now used intensively throughout the company by 40 operators in various departments. At the end of March 1994, the database managed by the system contained almost 6000 drawings and close to 7000 parts structures with subassemblies, optical parts and mechanical components. When development of a new product received the go-ahead in mid-1993, the time had come for the next step - the search for a suitable solid modeller. The crucial consideration was reverse engineering, a design method of enormous importance among an ever-expanding circle of consumer-goods manufacturers. Reverse engineering employs a physical 1:1 model to define exact geometries and generate the corresponding drawings. The market demands attractive products with smooth lines products that nestle in the hand. Consequently, manufacturers have no choice but to use tools capable of converting the hardware designs into correct CAD models. Other factors that cannot be ignored include the increasing popularity of modern prototyping methods such as stereolithography. These techniques permit highly detailed assessments even at a very early stage of product development. The CAD data provide the foundation that needs to extend to NC machining of tools for injection-molded plastic components and metal die-castings. Free-form solidsThe search began for a fast and robust new-generation modeler that would support free-form surfaces in 3D designs. When Alfred Hengst went to see what the market had to offer, a new product from HP had just earned itself a place in the front rank of eligible systems. PE/SolidDesigner is a new 3D software package based on an innovative geometry kernel called ACIS, developed as an OEM product in the UK, and now a central function in numerous 3D systems.After running benchmark tests on a number of solid-modeling systems, Alfred Hengst came to the conclusion that they were all more or less at par. However, each system has its strengths and it is very much up to individual users to discover the product best suited to their needs. PE/SolidDesigner performed well in the benchmark tests. It was when the tests were over, however, that the strengths of this modeler really came to the fore. A Leica development engineer had been casting an eye over the tests. Not a PE/ME10 user himself, this engineer sat down and began using the test installation. With neither familiarization nor training and more or less in his spare time, he started to model parts with the new system. The parts he modeled were not mere dummies for practice - they were parts needed for a new product. The results gave Alfred Hengst food for thought. He sent this same engineer on a week-long training course organized by the vendor of a rival modeling system. The trainee returned, declaring that PE SolidDesigner was easier to use without training than the rival product with training. Another important factor was the close family resemblance between PE/ME10 and PE/SolidDesigner (the links have since been exploited at every opportunity). The last vestiges of doubt were swept away when a milling test demonstrated that the SolidDesigner data could be used without difficulty for NC machining. Work processes have since matured to the extent that aluminum or plastic models are generated directly from the CAD data. A 4-axis milling machine is linked directly to the system for this express purpose. Fig 3: Camera housing designed with PE/SolidDesigner. The first parts originated
as an exercise in design-it-yourself. 3D design without trainingDesigners working with the 3D software from HP can generate complex components without advance knowledge of the relationships that will ultimately exist between the individual geometric elements. If a modification has to be integrated at an advanced stage of development, the system often knows automatically which boundary conditions will apply. The process of modification is simplified by an array of options, for example local operations restricted to individual faces. The first months' experience proved what had scarcely seemed credible: with this system, 3D modeling is almost as easy as conventional design work on a fully featured 2D system. The user interface of PE/SolidDesigner, moreover, is designed to ensure that PE/ME10 users feel at home from the start. Free-form surfaces had constituted another important consideration for the developers of the new product. Once again, the user who had taught himself the basics of the program caused some raised eyebrows. Without instruction and very much on his own initiative outside regular working hours, he set out to master the complexities of surface functionality. The outcome was a number of models of a quality that made them ideal for direct prototyping. These same models are now used to manufacture casting tools.Fig 4: The battery compartment of a camera. Virtually photographic display quality
permits effective simulation of the assembly process. Partners for solutionsHere at last, however, PE/SolidDesigner reached the limits of its capabilities. For the time being, a true surface specialist is needed when it comes to handling highly complex surfaces, complicated curvatures, surface smoothing or surface reverse engineering using digitized input data. For this reason, Hewlett-Packard recently entered into a technical partnership with Cisigraph with the aim of linking to and later incorporating the STRIM 100 system. 3D modeling dates back only a few months at Leica, but there is no denying its success.
Alfred Hengst sums up, "I am convinced that solid modeling is the only choice for our
products, with their high requirements in functionality and design. There was one thing
that was always difficult with 2D that is child's play with 3D - demonstrating that
the investment was worthwhile. |