Tesla reportedly wants to ‘gigacast’ a car’s underbody in just one piece

Other automakers are interested in this kind of mega-casting technique, in which a single large part is manufactured in a big press.
a tesla model y
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From the start, Tesla has eschewed traditional manufacturing, design, and sales models, and the company’s latest move could involve revolutionizing the production of its snub-nosed EVs, as a recent Reuters story reports. Previously, the EV giant proved it could reduce costs and parts by casting the front end and back end of its Model Y as whole sections instead of assembled parts, which Tesla calls “gigacasting,” on brand with its 10-million-square-foot Gigafactory in Austin, Texas.  

Tesla’s next step could be die-casting nearly the entire underbody as a singular piece versus the 400 parts it generally takes to assemble the same section of a conventional car, according to Reuters. As that news organization puts it, if Tesla manages to die cast the whole piece successfully, it would “further disrupt the way cars are designed and manufactured.” 

How does a house-sized die-casting machine work, and can it make that much difference in the industry? Read on to learn more.

How the casting process works

Tesla already uses what it calls a gigapress, an aluminum die-casting machine at its factories in the US, Germany, and China. In very basic terms, molten metal is injected into a mold (the “die”), then cooled, ejected, and trimmed. The die-casting process was originally conceived in the mid-1800s, and automotive companies have used this manufacturing method for decades.

In June, Reuters stated that Tesla also developed an aluminum alloy that allows it to “skip the heat treating traditionally used to increase the strength of the cast part.” That detail might trigger alarm bells, considering the tendency for Tesla vehicles to show signs of lackluster quality control when it comes to fit and finish. However, Ed Kim, president and chief analyst for research firm AutoPacific, believes Tesla approaches its body assembly differently.  

“The areas where Tesla has had issues in terms of quality are typically related to squeaks and rattles and panel fit,” Kim says. “But it has done a great job on innovative manufacturing techniques.”

The entire industry has taken notice, with Toyota, Hyundai, Volvo, and others pledging to explore a similar manufacturing avenue (and calling it “hypercasting” and “megacasting” instead). Large-scale die casting is a tricky process, and some critics point to the fact that a single flaw can compromise the whole piece. On the other hand, using a gigapress (or “megapress” as other automakers may call it) can help preserve profit margins by streamlining the process. 

The cost conundrum

Price is certainly a large factor, and Tesla says it cut related costs by 40 percent, according to Reuters, by using a gigapress on its most popular vehicle, the Model Y. That appeals to other automakers, like Toyota. 

“It doesn’t surprise me that Toyota has taken an interest in [gigacasting], because I’ve always thought of Toyota as a manufacturing company above all else,” Kim says. “Historically, Toyota really set the bar on smart, efficient manufacturing and figuring out ways to take cost out of the process without sacrificing quality.” 

Toyota executives may be kicking themselves for not adopting more large-scale die-casting first, he continues. The process is still very new, however, with much to prove, although automakers will certainly be watching. American companies are especially vulnerable to cost and revenue challenges, and the United Auto Workers’ current strike is creating a new flux in future plans; they may look at what Tesla’s doing and decide to go that route, but the relationship with the factories and those who work there adds a layer of complexity.  

Tesla has promised that a new $25,000 entry-level model is on the horizon, and that will require creative cost-cutting measures across the board, including perhaps the gigapress. 

“It’s so different from the assembly line model,” Kim says. “Given the rumored failures on the Cybertruck, the brand is particularly sensitive to manufacturing costs for its upcoming entry-level car and it needs to keep costs down.” 

The EV company’s ability to pull off using the gigapress on its Model Y contributed to its ability to slash prices, putting the competition on the defensive. Die-casting in this manner is technically difficult to execute and changes are very costly, which is why not everyone is jumping in right away, Kim says. Reducing manufacturing costs in a repeatable manner is the holy grail, he says, and automakers are all keeping an eye on this development. 

“Based on the success of the Model Y, Tesla can potentially pull it off,” he admitted.