Since Karl Benz invented the automobile in 1886, great changes have taken place in the automobile, most of which are attributed to the progress of manufacturing technology. As manufacturers put forward new methods to make different materials into more and more complex shapes and configurations, cars become more efficient, powerful, safe, comfortable and fashionable. Today, this progress continues with the development of 3D printing forms and the adoption of this technology by manufacturers around the world, including in the automotive industry. The rapid growth of the market value of 3D printing in the automotive market proves this. It is expected to reach $2.5 billion by 2023. Let's look at how the industry uses 3D printing today and consider future changes.

Prototype and validate new components
Automobile manufacturers have been using 3D printing to check the shape and assembly and to verify the operation of functional prototypes. For some full-size prototypes, such as checking the fit of rear-view mirrors, FFF / FDM technology with reasonable price can be used. For functional applications that require harder parts or smoother finishes, such as bases or aerodynamic components, resin and powder based technologies that can be used with composites and nylon are preferred. Material injection and 3D inkjet are commonly used for full-color display models and miniature models.

Manufacturing tools
The second most popular use of 3D printing in the automotive sector may be the manufacture of manufacturing AIDS, such as jigs and fixtures. Manufacturing tools using traditional methods is quite expensive and time-consuming, and geometric constraints translate into less efficient manufacturing processes and more constraints on the geometry of end-use parts. 3D printing manufacturing tools are lighter and more ergonomic, making it easier and safer for factory workers to perform their duties. This can save time and money on the factory site.

The injection mold of plastic parts and the mold core of metal parts can also be 3D printed, so that the traditional manufacturing methods and materials can be used to achieve greater design freedom. In addition, topology optimization has become a standard practice throughout the industry, where the geometry of the parts is optimized to achieve the strongest shape while requiring the least material. These algorithmic designs are usually more organic in structure, which makes it difficult or impossible to produce them without 3D printing. General motors, Volvo, Ford and many other companies use 3D printing to produce manufacturing aids to save costs, improve design and shorten delivery time. BMW even printed an orthopedic device in 3D, which can reduce the thumb pressure of factory workers when completing assembly tasks.

Manufacturing end use parts
Luxury and custom cars
Although the production speed using AM is steadily increasing, it is still the bottleneck of this technology. The production volume associated with automobile manufacturing is very high, with thousands of runs per part. For most additive manufacturing technologies (at present), this will be difficult. However, many high-end automobile manufacturers limit their automobile production to less than thousands, which makes additive manufacturing a feasible option. It is not as high-end as Rolls Royce, whose customized cars took a long time to make the company actually use am to increase the production number. BMW has provided tens of thousands of components for the phantom, such as buttons, parking brakes, etc. Other luxury car companies use 3D printing to customize their interiors, including Bentley, Porsche, BMW and Ferrari.

Replace parts as required
Many companies that provide 3D printing replacement parts for old cars also provide parts for new cars. Audi is one of the companies, which has been using am to make prototypes and replacement parts of cars for many years. Printing replacement parts on demand can greatly reduce inventory and transportation costs.

Production of complex geometries and assemblies
Some automobile companies use am only to improve automobile performance by manufacturing parts that cannot be manufactured by traditional manufacturing methods. Taking carbon performance as an example, he redesigned the suspension column for lotus sports car. The suspension combines 9 different parts into a 3D printed aluminum part, which not only reduces the weight but also improves the rigidity. Bugatti made headlines when he released the incredible pressure test images of the 3D printed titanium brake calipers of the Chiron supercar. BMW also 3D prints coolant channels into its M-series cylinder heads to improve performance. With the development of metal 3D printing, more and more automobile companies begin to use this technology to produce some parts to improve performance.

3D print frames and entities
Some companies are going further and printing their cars in 3D as much as possible, such as local motors, which 3D printed the entire body of the electric car strati. They can also 3D print the framework of their automatic bus Olli, which is being tested in several cities. Honda printed all the side panels for its micro commuter electric concept car.

Certification of 3D printing process and materials
Efforts are under way to create standardized 3D printing processes that can be certified to produce components for automotive applications. By certifying printing processes and materials instead of printed matter, smaller manufacturers can obtain certified hardware and immediately start producing products that meet industry requirements without having to carry out expensive certification processes themselves. Sympa research project is currently developing SLA resin, which will be certified for automotive use. The IDAM (industrialization and digitalization of automobile series process additive manufacturing) project coordinated by BMW is committed to developing am process and automation system to improve the efficiency of automobile manufacturing. The nextgenam project has very similar goals, but also includes the aerospace sector. These projects have made progress, so 3D printing is likely to enter more and more automobile parts.

The future of 3D printing automobile
Finally, in a few years from now, a fully 3D printed car will fall from the factory workshop. To that end, much progress will be required. Many companies have been committed to 3D printing batteries, and 3D printing electronic products are progressing smoothly. When the motor can print in 3D, we will stay there a lot. The magnet can print, so we are not far away. One of the remaining obstacles is the automation of robots to assemble all the different printing parts from different printers, and the organizations and projects mentioned in the previous section are already building advanced manufacturing facilities to achieve this goal. In the future, everything from engines, wheels to sensors and instruments will be used in cars in the form of 3D printing. The flying car we all promised may never come, but the 3D printing car is coming.