Ford used a new computerized design process coupled with rapid prototyping to develop the substantial 20-inch wheels for its latest Lincoln concept sedan, set to debut at the Detroit Auto Show in January. “When the wheels are spinning, the light literally dances from spoke to spoke,� says Gordon Platto, chief designer. “There’s an emotional connection with the moving wheel that the customer ultimately experiences. Now, we’re adding that experience to our process.� A simple, hands-on exercise cut almost two weeks out of the design process, explains Robert Gelardi, a senior designer who created the wheel. “To enhance and expedite our process, we rapid-prototyped six-inch scale models that were made overnight so we could look at the wheel with different combinations of finishes,� says Gelardi. “By expediting the three-dimensional evaluation, we achieved the right wheel design for this sedan very early in the development process.� (Rapid prototyping is the process of making a physical model of a part directly from 3-D CAD data.)
Once the final selection was made, designers used advanced design software called Bunkspeed to fine tune the wheel digitally. Bunkspeed allows designers to change vehicle features instantly.
Traditionally, wheels have been designed on screen and evaluated from full-size, 2-D renderings glued to tires. After favorite rendering was selected, a full-size model wheel was then produced. Any changes to the wheel at this point required additional full-size models – a costly and time-consuming process. Because renderings cannot show precise proportions nor can they recreate the effect of light on the wheel, it’s not uncommon to have to produce additional full-size models.
“Previously, we couldn’t take into account the ‘spin’ look during the selection process,� says Xitij Mistry, exterior designer. “With the six-inch models, we now have a method that is more accurate and efficient.�
The Result
The commanding 20-inch wheels represent the hallmark of American design, says Platto. “The trend in wheels is to make a statement. And these wheels do exactly that. They have a sense of importance, a presence, that you find on American vehicles,� he says.
To maximize the perception of the wheels’ size, Gelardi and Mistry used exposed lug nuts on the secondary spokes, allowing the major spokes to travel uninterrupted from edge to center.
“The sculpted shape of the spoke dives toward the center of the wheel, adding visual length,� says Gelardi. “This makes the wheel appear deeper and the tire wider.� says Gelardi.
The five/five spoke design marries luxury and performance in a bi-level arrangement. Five major spokes are positioned at the outer edge of the wheel and five secondary spokes, having a different shape, are placed farther back.
This portrays a sense of depth while accommodating multiple colors and finishes. With five/five spokes, customers have more opportunities to personalize their wheels, choosing polished or vapor-blasted alloy as well as a variety of colors that would match the vehicle’s body.
Depending on the paint and polish treatment of the spokes, the wheels will appear to have five spokes, giving the car a sporty, performance attitude. Or they will appear to have 10 spokes, underlining the sedan’s elegance and grace.
“Using different paints combined with different finishing processes gives you a very cost-effective way to achieve multiple appearances from one wheel,� Gelardi says.
Says Platto: “At Lincoln, we’re just as concerned with how a wheel looks when the vehicle is parked as when it is in motion. We want to make sure our wheel is beautiful in both cases, so we came up with an amazingly simple way to do that in the studio.�
