Michelangelo famously said, “The sculpture is already complete within the marble block, before I start my work. It is already, there, I just have to chisel away the superfluous material.” It appears that BMW took that advice seriously, but prefers to work in the medium of aluminum.
BMW insures extreme accuracy in vehicle design by using a process called “cubing.” In this process, the new car design is carefully milled from a solid aluminum block, revealing the vehicle “sculpture” within by removing the easily-recyclable superfluous material. The results create a model precise within fractions of a millimeter, allowing for ultra-precise design of assembly parts, components, and interior parts. Suppliers, working from BMW’s designs, can then send prototype parts for testing, allowing for more precise adjustments and a near perfect fit of the final products.
The resulting prototype model is also 3D scanned, allowing for even higher precision when developing interior and aesthetic components, in addition to mechanical parts.
The process isn’t cheap, however, reportedly costing $5 million for a vehicle. But the resulting accuracy in fit, function, and aesthetics of the vehicle and it’s components remains very difficult to match with other methods, including clay sculpting.
And using the process helps BMW keep the vehicle’s finish very precise and exact, whether it be car panels, console parts, or even seat frames. In contrast, Tesla doesn’t use cubing and it shows, as Tesla vehicles have a history of being criticized for large or uneven panel gaps and a variety of other fitment issues.
Milling car parts from blocks of aluminum isn’t new, but using it to create a full, precise model of a car remains a somewhat unique “secret to success” for fit and finish used by higher-end car makers, including BMW and Porsche.
Read a full report about cubing and how BMW uses it here:
https://www.forbes.com/sites/jamesmorris/2024/11/02/bmw-the-secret-to-car-quality-is-cubing/
Learn more about vehicle development using cubing.
