As a product design consultancy, we have been helping our clients consider product design and manufacturing issues for over thirty years, so are well positioned to advise you on the right materials, the right processes and the right suppliers (both in the UK and overseas). In particular, we can help you choose the best approach for your anticipated production volumes and target market.
CAD systems produce data that is capable of being programmed directly into production tools like sheet metal cutting and 5 axis milling machines for mould creation. These capabilities, plus the fact that CAD software is now capable of delivering geometry that is practically impossible to define in two dimensions, means that conventional, fully dimensioned engineering drawings may be redundant.
What has replaced fully dimensioned working drawings in many situations is a combination of CAD data plus drawings that show reference dimensions used to check overall accuracy; critical dimensions that relate to the fit of specific parts; critical tolerances; assembly details; surface finishes; and areas that should be left ‘metal safe’ for moulding purposes. These drawings are designed to be used in conjunction with the data and provide useful information in an accessible way.
Where the use of notes on a drawing will not work, due to language issues or the danger of misinterpretation, drawings can be produced using a comprehensive system of symbols and dimensioning known as GD&T. This system allows parts to be produced anywhere in the world, using any appropriate process with no part variations. The use of GD&T toleranced drawings provides a fully comprehensive, transferable and global solution, but can be complex and costly to implement.
If you have a clearly identified production partner and have no intention of using multiple suppliers, data and drawings will provide the most cost-effective system, although it is clearly vulnerable to the supplier suffering a commercial collapse. The GD&T approach is more suited to global production approaches, where identical parts need to be made in a number of production plants.