Mechanical designers are being tempted into using solid modelling by low-cost software offers and new, easier-to-use products and features. The aim of these enticements is to convert 2D CAD users to 3D, although users of older solid modellers are also said to be ripe for change.
At the heart of this marketing effort are vendors of mid-range solid modellers: well-established companies like Unigraphics (which also develops a high-end system) and SolidWorks, as well as newcomers like Visionary Design Systems. All normally offer Windows-based solid modelling software for around £4,000.
Until the end of the year, Unigraphics is offering 500,000 free copies of a software package called Solid Edge Origin, which contains all the 2D functions of Solid Edge, Unigraphics’ mid-range solid modeller, plus the ability to evaluate 3D modelling.
For £400, the company is also offering a basic solid modelling package, Solid Edge Origin 3D – a subset of Solid Edge. The target market for both Unigraphics products (which can be ordered over the web from www.solid-edge.com) is the world’s 2D mechanical CAD users, most of whom use AutoCad.
According to Unigraphics, 3D systems will account for 77% of the 4.5 million installed mechanical CAD seats in 2003. This year, 3D systems are expected to account for about 42% of the total.
The advantage of 3D over 2D is that it produces an unambiguous representation of a product that is more easily understood by a wide range of people. `It is much easier to see when parts don’t fit, to make any last minute changes to the design and to carry out downstream activities like stress analysis,’ says Simon Booker, SolidWorks’ UK regional sales manager. `Also, 2D drawings are produced automatically from the 3D model.’
SolidWorks and other new solid modellers are affordable, run on PCs and are easier to learn and use. Booker estimates that a third of the enquiries received by SolidWorks are from users of more expensive high-end CAD systems such as those developed by Dassault (SolidWorks’ parent), Parametric Technology, SDRC and Unigraphics. These systems typically offer surface and solid modelling, the ability to handle very large assemblies, such as cars, and a range of integrated add-ons.
High-end CAD systems are favoured by large manufacturers, which continue to put pressure on their suppliers to adopt the same software, regardless of its cost or suitability.
Two main reasons are cited for this: first, it eliminates the need to transfer data between different CAD systems and, second, it maintains associativity – that is, if the design changes, everything associated with that design is updated.
Mid-range vendors attempt to address the problem of data transfer between companies by offering a wide range of products and integrating selected software with their modellers. Delcam, which sells solid and surface modelling and CAM software mostly for toolmaking, is adamant that the data transfer issue is a red herring.
Most of the problems occur, says Peter Dickin, Delcam’s marketing manager, because of misunderstandings about the tolerance of the model being transferred. `As long as people communicate, data transfer using something like Iges should be reliable,’ he argues.
As for the notion of associativity between CAD and CAM data, Dickin insists that for complex shapes it is impossible for product design changes to be reflected in tooling design. `The cutter you’ve chosen to generate the tool path may no longer be appropriate and for mould tools you’ve got to allow for material shrinkage,’ he says.
Arguments such as these are unlikely to affect large manufacturers’ overall CAD/CAM strategies, but companies are still willing to try new products. An example is IronCad, a solid modeller developed by Visionary Design Systems of the US, which has sold about 1,000 copies since its launch just over a year ago. It is being sold in the UK by Leonardo Computer Systems.
Alan Goswell, Leonardo’s managing director, says one UK company found that with IronCad, a task which took more than six hours on Pro/Engineer was completed in 86 minutes. The manufacturer concerned has not replaced Pro/Engineer but has purchased seats of IronCad for conceptual design.
`Users found that they could get their ideas into 3D very quickly with IronCad because they didn’t have to bother with parametrics,’ says Goswell.
IronCad’s speed, claims Goswell, is attributable to the fact that it is more user friendly. Instead of constructing models using 2D sketches, constraints and parametric relationships, IronCad users can select from a number of primitive shapes from a tool bar, drag and drop them on the screen and adjust the size and shape. Parametric relationships and constraints can be applied to finalise the design, if needed.