I was invited to spend an evening learning about the clay modelling process that goes on behind the scenes at Ford, by 'Ford Sculptors' including Denise Kasper, who was giving the demonstration for a group of journalists, designers and design students at Hoxton Arches' Arch 402.
Even in the digital era, Ford believes that clay modelling is still one of the most important elements of the car design process, so every car is designed in clay before being scanned in as a 3D CAD model.
But before the Sculptors can begin work on their designs, designers give the Sculptors an idea of what they're aiming for by creating Photoshop sketches. Normally there are seven or eight designers working on a car project at one time, and they'll produce around 100 sketches each.
Sculptors work closely with the designer, who is in effect the director of the clay project, to ensure that the result fits the designer's brief.
The sketches are not a solid car design idea, but instead they illustrate the lines the car should have. So, for the new Ford Mondeo (the subject of the demonstration) the designers suggested that lines should give the impression that it's a powerful car, but still elegant. Ford managers will then pick around 10 sketches that they like most, and those will be turned into clay models.
Every clay model starts as a foam and steel base, which the hot clay (at 60 to 65 degrees) then goes on top of (this means it weighs two tonnes instead of five). A milling machine is then used to fashion that clay into the basic proportions of the closest model to the car that's being designed. In this case, it was the previous generation of Mondeo.
The milling machine leaves a rough finish, which the Sculptor will then begin work on.
The first clay models are designed at a 1:4 ratio (the demonstration model is to a much smaller scale of 1:10), before the four best are chosen to be turned into full-scale models. Only two models will be created, but those models will have a different design on each side to represent all four of the designs chosen.
The Sculptors use various different tools, including flexible steel tools at different strengths and tools made from wood for more precise lines.
During the sculpting process, the modellers use their tactile senses rather than sight alone to determine whether there are bumps and bubbles on the surface, which will cause problems when it comes to scanning the model.
When the model is ready, the designer will arrive armed with blue tape that's used to mark out tweaked lines that the Sculptor will create.
Once the lines are approved, they get rounded by a soft, paper-like tool. All lines are described as a radius rather than an edge, because there are no sharp edges in car design for safety reasons.
The final part of the process takes advantage of a stretchy metallic film called Dinoc to be placed over the model, which can require more than four people to apply to a full-size car. The film is used to help see what the car will look like outside, showing all of the lights and shadows caused by different lighting conditions.
3D-printed components including wing mirrors, handles and grilles are attached to the clay to give a more realistic impression of what the car will look like. They also get painted with real body colours once they've been finalised, so it can be difficult to tell that the model isn't actually a real car.
Every two or three months, management comes to see the progress of the clay designs. If they like it the Sculptors continue, if not they have to change it.
Throughout the modelling process, the clay models are regularly scanned and examined as 3D models. Every time the Sculptor wants to 'save' a design they've created before editing it, they'll scan it. That means, if the new design doesn't work as well, they can recreate the exact design they'd previously sculpted.
They're also scanned for the engineers to examine to determine whether the designs are actually feasible. Sometimes the designs don't actually allow enough space for all of the internal components so require tweaking.
According to Denise, though, nothing is done purely in 3D. None of the designs start life there. Surfaces are always taken from what's been created by hand in clay.
Eventually, after a long, two-year process, the car can be manufactured. Here's the result! The new Ford Mondeo, which will hit the streets next year.