Gear shift for the car industry

The electro-mobility revolution has brought with it a radical rethink around car production methods. Both established and new car producers are looking to simplify their production methods and save costs by reducing the size of their factories by producing ever-larger components that require fewer robots to assemble them. The industry is even changing the materials they use to manufacture cars.

Car manufacturing traditionally involved stamping sheets of steel into the shapes needed. A typical car would be made up of hundreds of different steel parts that needed to be welded and fitted. In 1993, the car manufacturer Audi took a radical step when it introduced the Audi Space Frame concept for one of its luxury sedans. It was the starting point for a new manufacturing process. Instead of steel, Audi used aluminum and integrated casted structural parts created by using a process called high-pressure die casting. It involves molten aluminum being shot into a die or mold in milliseconds and then being solidified under high-pressure compression.

Between 2000 and 2010, a handful of luxury car manufacturers started to follow Audi’s example and began using structural castings in their designs. While the parts were varied the volumes were low as early adopters still restricted their usage to luxury ranges. Over the following years, more manufacturers switched to die casting. One example is the production of the shock tower, an integral part of a car’s body in white, the stage where the car frame has been joined together and is yet to be painted.

Cinelli believes the move to larger machines has in the past been inhibited by what he describes as a “chicken and egg” situation. “Car designers did not think about large component sizes because the machines to make them were not available and we had no reason to build bigger machines because there were no components requiring such large machines,” he explains. Now that the market has changed, car manufacturers realize that to remain competitive they need to fundamentally rethink their production setup – with the die-casting process at the heart to increase flexibility and efficiency.

It is the rise of electro-mobility that has proven to be the greatest market disruptor. New car manufacturers realized that going straight to die-cast production was more cost-effective when it comes to start-up costs. This is particularly true for newcomers that don’t already have the stamping and assembly lines in place necessary for traditional sheet metal production.

Companies such as Tesla are also finding that larger machines, when producing a single large component, can result in doing away with costly welding and assembly processes. Fewer processes require a smaller factory footprint and overall lower investment to produce greater volumes. Tesla is currently using 6,000-ton die-casting machines to produce the rear underbody for its Model Y car in the US and in China, according to statements made by Tesla CEO Elon Musk in the 14th episode of the podcast “Third Row Tesla” released in April 2020.

This single piece casting combines 70 different stamping parts and reduces the number of robots required by 300 and the factory footprint by 30 percent. Larger machines are also capable of producing more components in one shot. Shock towers are typically cast one or two at a time, taking around 70 seconds each. A die-casting machine large enough to produce four shock towers in one shot can significantly increase productivity and cut costs.