Tesla is working with multiple 3D printed sand casting companies

Tesla is trying to master the art of casting large, complex car parts in one go. If it succeeds, it will change how cars are made, making it faster and cheaper to produce electric vehicles (EVs). According to a Reuters report, five people familiar with Tesla’s plans revealed that the company aims to revolutionise the traditional, complicated, time-consuming, and expensive process of creating large components like a car’s underbody, which typically requires assembling numerous smaller pieces.

Tesla’s Gigafactory (Image Source: Tesla)

To overcome these challenges, Tesla is looking into 3D printed sand moulds, which are much cheaper and quicker to make than traditional metal moulds. This way, they can test new designs without spending a ton of money. Reuters sources revealed that the carmaker is also experimenting with special types of metal that work well for these big, one-piece castings. The goal is to speed up how cars are made and make electric vehicles more affordable.

Innovative casting
According to insiders who spoke to Reuters, this seemingly simple shift in material choice could be a game-changer for the entire industry. Traditional moulds made from metal are expensive and time-consuming to alter. For example, a dashboard mould alone can cost between $100 000 to $150 000, while a mould for a bumper might range from $50 000 to $100 000. Engine component moulds can start at around $20 000 and go up to $80 000 or more, depending on the complexity and material.

A single tweak in the design of these moulds could cost as much as $100 000. But when it comes to creating an entirely new mould from scratch, the costs can soar up to $1.5 million, especially for large, complex structures like a car’s underbody. A sky-high figure like this accounts for detailed design work, specialised machinery and labour, rigorous testing to meet quality and safety standards, and the cost of durable materials required for casting. Such high costs make Tesla’s exploration of 3D printed sand moulds a potentially revolutionary development in the automotive manufacturing industry.

An auto part printed out of sand using binder jetting (Image Source: ExOne)

In contrast, 3D printed sand moulds offer a far more flexible and cost-effective solution. Engineers can easily revise designs using a digital design file and 3D printers, and a new sand mould can be printed within hours at a fraction of the cost. This dramatically shortens the design validation cycle from as long as a year to just two to three months, allowing for more rapid innovation and adjustments.

Moreover, Tesla leverages the flexibility of 3D printing with sand to experiment with intricate designs previously considered too risky or expensive. For instance, Tesla’s engineers can now include hollow subframes in their one-piece castings to reduce weight and improve crashworthiness. Engineers place 3D printed sand cores within the moulds to create these hollow structures. After casting the metal, they remove the sand, leaving the desired hollow spaces behind.

Mould magic
Tesla prefers in-house solutions and tends to be secretive about its production techniques. Despite this, the company has embraced 3D printing for various purposes. A Forbes report revealed that Tesla’s applications of this technology range from creating door handles to prototyping entire chassis. For Tesla’s specific need to create 3D printed sand moulds, binder jetting technology would be the go-to method. These printers rely on layering, spreading sand on a tray, and then selectively applying a liquid binder to shape the mould according to the digital design. The machine repeats the process layer by layer to complete the mould and then removes the unbound sand to reveal the finished product.