When Elon Musk was interviewed in an episode of the Third Row Podcast earlier this year, he noted that the Model Y crossover’s rear underbody would eventually be built with a single-piece casting. This is quite a bold target, and one that can make the Model Y into one of the most cost-effective vehicles on the market today, electric or otherwise. 

“The current version of Model Y has basically two big high-pressure diecast [HPDC] aluminum castings that are joined and there’s still a bunch of other bits that are attached. Later this year. We’ll transition to the rear underbody being a single-piece casting that also integrates the rear crash rails,” Musk remarked.  

There are many advantages to using a single-piece cast for the Model Y. The vehicle could be built in a relatively simple manner by using fewer parts, helping the company optimize its production costs. Developing such a design only takes a lot of time and effort, as indicated by Elon Musk in the podcast. 

“It gets better. The current castings, because you’ve got to interface with so many different things, we have to CNC-machine the interfaces and there’s a bunch of things that have to be joined; they have datums on them and that kind of thing. The single-piece casting has no CNC machining – it doesn’t even have datums. It took us a lot of iterations, by the way, to get there,” the CEO added. 

It appears that Tesla is now at a point where it is ready to pursue the Model Y’s single-piece cast. As indicated in a recent report on SAE Automotive Engineering, Tesla has purchased a machine from the IDRA Group, an Italian firm that makes HPDC equipment. What is rather interesting is that the machine that Tesla purchased is a gargantuan piece of equipment capable of producing the Model Y’s special components. 

The machine that Tesla purchased, called the IDRA OL6100 CS, features an upgraded locking force that’s specially designed for the Model Y’s castings. Interestingly enough, the OL6100 CS is fondly dubbed as the “Giga Press” due to its size and power. The machine is 64 feet long and 17 feet high, and it weighs a whopping 410 tons. That’s roughly as heavy as five Space Shuttles. 

Laurie Harbour, president at Harbour Results Inc., a manufacturing consultancy firm, noted that the new machine could effectively optimize the Model Y’s production process. With the Giga Press in use, Harbour estimates that Tesla could save about 20% on labor cost. 

“Even with a big cycle time, you eliminate all the labor to assemble pieces and subcomponents. You’re saving on automation cells, you’re saving on people. It would be tough to put dollars to it, but think of multiple suppliers doing stampings, you could save maybe 20% on labor cost. And reduction in footprint is major. My guess is that it’s a net-net efficiency gain,” she said. 

What is particularly interesting is that the Model Y was already highly optimized to begin with. Unlike the early production Model 3, which featured over 70 pieces in its rear underbody, early production Model Ys only had two large casts at the rear. This was confirmed by automotive teardown expert Sandy Munro, who conducted a thorough teardown of the Tesla Model Y from top to bottom. 

Reflecting on the Model Y’s current casts, Munro noted that the vehicle had “two of the biggest castings we’ve ever seen in a car,” especially one in a consumer vehicle the size of the all-electric crossover. The teardown expert stated that other companies, such as BMW and Audi, have all used castings, but nothing comes close to the one that Tesla currently uses in the Model Y. And once Tesla moves to a single-piece casting system for the vehicle, Munro noted that the American electric car maker could “win the price.”