Third dimension is essential for efficiency

Designing in 3D, rather than 2D, may be harder work for the designer, but companies are increasingly finding it to be essential for their business. Timothy Stubbs, engineering manager of Fortress Interlocks, told delegates at the recent Product Development Show, how making this switch had helped his company develop a range of lighter duty, safety gate switches. "I don't think we could have developed the product without the tools we had," he said. "It's very complicated, and 3D visualisation was essential." Fortress used Pro/Engineer Wildfire 2 and PDM/Link to design its products, which are made up of interlocking modules equipped with locking bars and PCBs. They fit onto aluminium guarding or fascia plates. Mechanism design built into Pro/E was used to check for possible interference during assembly of modules, and potential problems identified and eliminated prior to the manufacture. The handle design was imported into Pro/Mechanica and showed up a problem - resulting in a design modification. PDM/Link was used to assign tasks and manage the change process. The company practices concurrent engineering using project teams. There are only two R&D mechanical design engineers plus Mr Stubbs but the project teams also involve the representatives from quality and purchasing. Concept to production was just over two years, with other design and redesign projects undertaken at the same time. The company is now moving onto Pro/E Wildfire 3. Those longer in the engineering design business started in 2D. Dave Salisbury, chief designer at Engine Developments (Judd Power) recalls: "When we started, we were all using pencils." The company produces mainly sports and touring car engines, and its "main trade" at present is engines for cars to race at LeMans. The first package used was Cadkey, which is 2D and some of the designs are still in Cadkey. The company bought its first SolidWorks package from NT Cadcam in 1996. At the time, Mr Salisbury said that its ability to produce drawings was limited, but it has since become "very powerful". All new parts are now designed in SolidWorks. Because some parts are still in Cadkey, it is sometimes necessary to use the two packages together - as in the recent redesign of a 5 litre engine. The engine block was still in Cadkey, but everything around it was to be new. Fortunately, Mr Salisbury explained, SolidWorks can read Cadkey files - so it is possible to take a Cadkey drawing as a sketch and then extrude it in 3D. 3D is of great benefit when working with casting pattern makers, who can take a 3D model, put in a contraction figure, and use the revised model to generate NC machining instructions. Time from concept to a running engine is now about six months: it was previously up to 12 months, says Mr Salisbury. Using Protomold's rapid injection mould tool service is not even possible without working in 3D since it begins by uploading a 3D CAD model in order to obtain a quotation in half a day. The company specialises in the rapid manufacture of aluminium tooling. The standard service is 15 days for delivery, although 3, 5 and 10 days services are all available. According to commercial manager Damien Hennessey, the tools are guaranteed for life. If one wears out, the company makes another. Founder and chief technology officer Larry Lukis says that he got the idea for Protomold when designing plastic parts for large format colour printers in another company. He found that conventional moulds took weeks to be delivered, and rapid prototyped parts did not have the robustness of the real thing. Another company that has moved from 2D FastCAD and AutoCAD to 3D is Microlights, which makes lighting solutions for the retail and leisure markets. The company has adopted Autodesk Inventor after a detailed evaluation process. Engineering manager Daniel King says of it: "Inventor helps us to realise and modify designs very quickly. We are currently using it to produce around five new designs a month." He says it takes him less than a day to create a product concept that can be used to produce drawings for initial cost estimates. Within two days he can produce a "more or less fully engineered design", he says. "Inventor's 2D drawing capability is a great time saver. We can produce drawings to send to our suppliers, complete with any number of views and sections, directly from Inventor in a matter of minutes," he says. "Before, that would have taken at least a week." Economies are achieved by taking a standard design and creating a number of variations by modifying the initial design, adding, deleting and modifying components and assemblies as required. Supplier's component designs are imported in IGES format to add to the extensive library of Microlights' own parts. "If we get a substantial new order from a client for a legacy product that was designed in our previous FastCAD and AutoCAD systems, we now remodel the product in Inventor and re-engineer it to achieve the required price, performance and margin," explains Mr King. In the case of a special design just completed, he says: "In essence, the unit comprises 12 T8 fluorescent tubes in a very large rectangular box suspended from the ceiling. In just two days, I've been able to save around two days of time on each special that we design. Given that 50 per cent of our 150 designs a year are specials, that adds up to 150 days a year of design time and effort saved." For those still moving from AutoCAD to Inventor, it is possible to copy data from AutoCAD and paste it directly into Inventor. Autodesk cites 10 reasons why it thinks customers should move from AutoCAD to Inventor 11 - including the automatic ability to view parts and assemblies from models, and annotating drawings by retrieving information directly from the design. Working in 3D allows the user to check that all parts fits correctly and animated sequences can be created for use in training videos, assembly instructions and sales presentations. Tube and pipe runs and cable and wiring harnesses can be added that comply with user-defined design rules and stresses and deflections of parts can be simulated under real-world conditions with the Finite Element Analysis functionality. Engine Developments The Protomold Company NT CadCam SolidWorks Autodesk Pointers * 3D design is harder to do than 2D design -- but it can immediately be used to generate tooling * Other advantages include the immediate ability to carry out fitting, assembly and finite element studies * Legacy 2D data can usually be read by 3D CAD packages and subsequently extruded into 3D models