Reducing time to market is a key issue for all manufacturing companies aiming to create an edge in today’s competitive marketplace. This statement couldn’t be more true than in the automotive industry, where new vehicle development cycles have been reduced by as much as 40% over the past 10 years.

Luxury carmaker Jaguar is no exception. Now part of the worldwide Ford organization, Jaguar is a company with an enviable reputation for design innovation at the forefront of automotive technology. The Jaguar S-Type luxury sport sedan is just one of several vehicles to have benefited dramatically from the company’s investment in stereolithography technology from 3D Systems.

“Rapid machining and prototyping methods enable us to turn CAD data directly into physical models in hours rather than the days or weeks it would take using traditional craft-based methods,” says the company’s rapid prototyping & tooling manager, Mark Barrington.

It is no surprise that his department’s wide-ranging tool and model making services are in
constant demand by the engineering functions at the company’s Whitley Product Development Center in Coventry, England.

However, it was the approval of an ambitious new product cycle plan that signaled a marked increase in the group’s workload and led Barrington to set about looking for a solution that would enhance the existing prototyping capabilities of his department. In this regard, the ability to support the timely manufacture of complex castings, such as manifolds and cylinder heads, was regarded as a key requirement of the new system.

On investigation, it was soon realized that these criteria limited the range of potentially suitable rapid prototyping processes.

“The SLA models proved to be invaluable in helping us to optimize the vehicle within the required timescales.”
                                                        Mark Barrington, Jaguar

3D Systems Hits the Mark
As part of the evaluation exercise, Barrington and his colleagues invited three suppliers to take part in benchmark tests. They also identified a list of key assessment criteria and compiled a series of weighting factors, which emphasized their need for fast and reliable model production, high process accuracy and the ability to create fine detail.

The results of the benchmark led to the installation of a 3D Systems SLA 5000 machine as part of a turnkey facility commissioned at the Jaguar site.

“Since then, it has performed well, operating 24 hours a day, seven days a week,” reports
Barrington. “We normally output five or six small components at a time, and I estimate that we produce more than 100 completed models every month on the equipment.”

Improving Design and Performance
In addition to its use for the generation of parts ranging from door handles and dashboards to engine and power train components, the new system has played a major role in optimizing the aerodynamics of the Jaguar S-Type.

Aerodynamic performance is a crucial factor affecting the maximum speed, fuel economy and high speed stability of any vehicle. One of its key attributes is drag coefficient (Cd); a parameter that normally sets stringent target figures early in any development program.

Almost 30% of total drag is known to be generated through the engine bay, cooling pack and underside of a vehicle; limiting the value of traditional clay models for aerodynamic testing. However, by using their SLA 5000 system, Jaguar’s rapid prototyping team was able to create detailed 3/8 scale versions of the vehicle’s complete front and rear suspension assemblies, which were subsequently fitted to test models for evaluation at the Motor Industry Research Association (MIRA) wind tunnel facility.

Working in this environment, the performance of the vehicle was measured and quickly refined. Ultimately, the wind tunnel tests were shown to correlate closely to the results achieved using full-size vehicles.

“With a discrepancy of less than 10% between the two sets of readings, the SLA models proved to be invaluable in helping us to optimize the vehicle within the required timescales,” adds Barrington. “The SLA system’s ability to rapidly process modified parts also enabled a variety of wing mirror and body styling components to be evaluated as part of the demanding test schedule.”

The end product is a milestone vehicle for Jaguar that has already been confirmed as the spiritual successor to the company’s 1960s design classic, the MK II.

But in turn, the Rapid Prototyping team at Whitley has also been acclaimed for its innovative use of the technology, by winning the “Award for Excellence” at the European Stereolithography Users Meeting.

“The S-Type represented the first major development program to be undertaken with the help of stereolithography,” says Barrington. “So, we are both delighted and surprised to be selected for this award.”

“The SLA suspension models have made several appearances at technical presentations and launch events since their use in the wind tunnel development tests,” he adds. “I am sure they will serve as an on-going reminder of what can be achieved by using the best tools for the job.”