The construction of vehicles is a very well established and understood process. While there are definitely variances between automakers, for the most part, they all use very similar techniques.
The reason for this commonality is very simple – it works and what we have today has been achieved by iterations and learnings over a number of decades.
So far, Tesla has followed a fairly similar model, assembling the body form a large number of individual parts however, all that is about to change.
Manufacturing experts like Sandy Munro highlighted potential areas for improvement with the rear section of the Model Y. A couple of years later, Tesla implemented a big change with the Model Y, they began casting a single large aluminum section for the rear assembly. This dramatically simplified the production of the Model Y.
This simplification is critical in reducing the production time of each vehicle, with a nice side effect being reduced weight and cost savings. This also reduced the costs of the robots that were used to assemble the 70 components.
This one change, reduced the number of parts in this section of the car from around 70, down to just 1. Not only is a single part faster to produce, but simplifies things, reducing the possibility for issues in the assembly process, making manufacturing more reliable.
When Tesla made this change, they took the opportunity to review all options to include things like suspension mount points, cable runs, and more on the rear casting. It’s this kind of opportunistic thinking that challenges the status quo, that many other automakers simply don’t do.
Naturally, once you find improvements like this, you want to repeat them in other areas. With the change working so well in the Model Y, it’s not surprising Elon Musk has considered expanding this to an even larger scale.
Casting small to medium aluminum components is nothing new, with aluminum engine blocks now common in ICE vehicles. That said, scaling up the size of parts produced in aluminum isn’t easy, in fact, it’s quite problematic, with many issues needing to be overcome to accomplish it.
Firstly, the machines required would consume a large amount of valuable space inside factories, but secondly, they just don’t exist in volume, therefore they often have to be custom-built which is also incredibly expensive. This is why most other manufacturers would cast multiple smaller components and weld them together, it’s easier, but not better.
Last week, during Tesla’s Battery Day investor event, Elon Musk revealed they are moving to a new way of building vehicles.
The entire front section and entire rear section of the underbody will be cast in whole pieces of aluminum. The machine used to do this, is now known as the Giga Press, the largest aluminum die casting machines in the world.
Made by Idra Group in Italy, they are reported to have a clamping force of 55,000 to 61,000 kilonewtons (5,600 to 6,200 tf). Each machine weighs 410–430 tonnes, so it’s also not something you can just install anywhere, you need very serious foundations to support that kind of weight.
Included in Tesla’s Q2 2020 Update, was a photo of a Giga Press in Tesla’s Shanghai Gigafactory on the Model Y line.
Recently Musk visited their latest rapidly evolving European Gigafactory in Germany. During the trip, he revealed that the Model Y will be ‘radically redesigned‘ and now we know what he meant by that.
The Freemont factory is pretty full, so adding massive casting machines isn’t as practical as it is in new factories. At least for now, Tesla are installing a second Mega Press at their Freemont factory, outside and thanks to some crafty drone shots, we can see that being installed.
The changes to vehicle production doesn’t stop there. Tesla are also re-imagining how the floor of the vehicle comes together.
Instead of batteries being installed into packs and then packs being installed into the chassis, the battery cells will now installed into the floor of the vehicle directly, which will also supply cooling to the surface of the larger 4680 cells.
These new cells will combine to become a structural component, as seen below in this mock-up in Munro’s latest video. These 3 components, will combine to create the entire substructure of the car.
Back in July 2019, we learned that Tesla had patented a massive whole vehicle casting machine. While the drawing used in the patent application shows an entire vehicle being cast (inc parts of the upper body as well), in the short-term, it seems they’re focused in the shorty-term on just the complex undercarriage, but this perhaps foreshadows even greater ambitions for optimisations and single casting.
It’s not clear how fast the parts can be created, but clearly, the production time would be a dramatic improvement over previous techniques of making, then assembling the individual compontents.
Sure, the cost of custom-built gigantic casting machines is likely to be in the millions, with enough volume, they will lower the cost per vehicle.
Sandy has a great new episode on the Munro Live YouTube Channel talking about this manufacturing revolution by Tesla. If you haven’t watched it yet, it’s definitely worth a watch.
Typically automakers invest in a vehicle development process that takes around 4-6 years to complete. Once the vehicle ships, the goal is to then produce as many as they can without making changes, to pay back R&D expenses, then hopefully make a little profit.
As the years roll on, we’ll typically see few designers thrown at the task of refreshing the front, changing some colours on the interior, but largely keeping the car the same. These tweaks can last many, many years as the manufacturer extracts maximum value from their investments.
That tried and true model has worked well, but now there’s a very different competitor, one that plans on making millions of vehicles in the future, so in these early years of growing up, Tesla are proving they’re willing to rethink and invest in making the best machine that makes the machines.
Musk expressed during Battery Day that he believes everyone will eventually many EVs, everyone will eventually figure out autonomy, but the winners in the future will be whoever can make the best factories.
As Tesla finds new ways to drive down costs, it positions them well to head towards a more affordable car that many more people could afford. At an estimated US$25,000, that would be affordable by many, many more people.
If demand is strong for a Model 3 and Model Y at their current premium prices, then a cheaper Tesla that features great performance, range, and autonomy features is also likely to be a smash hit. That’s due in 2023 and we’ll be watching closely on Telsa’s progress.