Thursday, 25 September 2014
Enhancing design competitiveness
PRODUCT design ideas of the yesteryear were rendered on paper by skillful designers who were both artistic and technically competent.
The ideas were then translated into three-dimensional “mock-ups” or models, using clay, wood or paper board. Skillful craftsmen carved out or assembled the mock-ups for visual assistance to evaluate the aesthetic, dimensional proportionality, manufacturability and tool-making constraints of the product design.
Photographic snapshots of the mock-ups were used for advertising campaigns of the products.
Similar steps were taken in those days to design and develop automotive parts and components for a new vehicle model introduction.
The practice was time-consuming.
Component mock-ups were merely for visual assistance and were not intended for mechanical testing and engineering evaluation purposes. This further prolonged the process of design-to-manufacture time frame.
The problem persisted when the vehicles’ original equipment manufacturer (OEM) insisted that vendors present small quantities of the parts being developed in the form of finished products.
In this case, the vendors have no alternative but to proceed with the fabrication of the expensive production molds or dies to produce the part samples.
The risk can be on the vendors should the parts presented were not accepted. More often than not, the vendors were asked to reproduce the samples through further modifications on the molds or dies on condition that the new samples were delivered within narrow time frames.
The advent of digital technology has helped to minimize the problems by virtually eliminating the manual mock-up stage of the product development process.
The introduction of computer-assisted prototype-making machines, such as the “Stereolithography (SLA)” and “Laminated Object Manufacturing” are now able to generate accurate parts prototypes for visual analysis.
The parts are rendered on the computer screen in the initial design stage. Upon finalisation, the data are transferred to the machine for prototype generation. The prototype can be produced by having the exact visual appearance of the expected finish product with dimensional accuracies.
Since the prototypes are generated using materials such as polymer, in the case of SLA, they are not suitable for physical or mechanical testing, but are useful for visual analysis and fittings or assembly in the vehicle.
The technique is not only able to generate accurate prototypes, model-making time frame is shortened multifold. The process is now recognized as “rapid prototyping technology”.
Rapid prototyping does not overcome the problem of the OEM requirement for vendors to produce a few working parts samples for mechanical testing and other engineering evaluations.
This requirement is fulfilled by the “rapid tooling” technology, which comprises “soft-tooling” and “bridge-tooling” techniques.
Soft-tooling is made from silicon rubber resin and used to produce plastic-prototype components using Polyurethane Resin. Accuracy is rather limited, but suitable for production of 100 rigid samples.
Bridge-tooling is an intermediary between soft-tooling and the actual production tooling strong enough to produce some 3,000 working samples required for the new design and engineering evaluations.
Rapid tooling fabrication time frame is about one fifth and costs some five per cent of the production tooling, thereby reducing the risk of vendor’s parts bidding significantly.
There are a few rapid prototyping operators locally with little or no rapid tooling capability. In order to encourage product design and development activities among the local vendors and the public at large, the availability of a comprehensive prototyping facility in a one-stop center is appropriate.
The initiative will enhance the local design capability and competitiveness for the local industry.