I really, really, really did not like this post. I found it to be riddled with bad assumptions, questionable unsupported claims, and critical omissions. I don’t think any of the core arguments survive close scrutiny.
Moreover, I took serious issue with the tone throughout. The first half hand-waves some seriously questionable claims into existence with strong confidence, while the second half opines that everyone who ever thought otherwise is some combination of sycophantic, incurious, brainwashed, or an idiot. I would have appreciated more intellectual humility.
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My read is that this post totally whiffed on the entire subject of die casting cost savings.
The chassis of cars is a relatively small fraction of their cost. The cost of aluminum die casting and stamped steel is, on Tesla’s scale, similar. Yet, there were so many articles saying gigacasting was a major advantage of Tesla over other companies.
To be clear: the cost savings argument for die casting is little to do with the cost of the chassis itself, it’s mostly an argument about the cost of body assembly.
In an automotive assembly line one of the most labor-intensive, challenging, and expensive steps is the “body shop,” where a car’s structural components are assembled into a “body in white.” Die casting saves time and money by reducing the number of welds, bolts, etc. required to go from components to body. It also cuts down on total weight, waste material from manufacturing a larger number of components, and the number of steps one can introduce tolerance errors.
Here is an example from the Model 3. Switching from traditional assembly to die casting cuts out 169 separate metal parts and 1600 welds. Those costs add up! Look at the difference in estimated variable costs.
in short, your claim: “The cost of aluminum die casting and stamped steel is, on Tesla’s scale, similar” both seems to miss the entire point and run against literally everything I have seen written about this. You need citations for this claim, I am not going to take your word for it.
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The price thing alone seems like a post invalidating miss, but I was pretty alarmed by the sheer number of other strong assertions made with weak or no supporting evidence. Some of these seemed obviously wrong.
Tesla has been widely criticized for stuff not fitting together properly on the car body. My understanding is that the biggest reason for that is their large aluminum castings being slightly warped.
Tesla’s panel gap issues predate the giga press by like a decade and has always been attributed to wide tolerances for all parts and lazy QA (de-prioritized in favor of R&D). I have absolutely no idea how you got to this “understanding.” Citation please?
As for voids, they can create weak points; I think they were the reason the cybertruck hitch broke off in this test.
Or the geometry of the frame was insufficiently optimized for vertical shear. I do not understand how you reached this conclusion.
BYD is still welding stamped steel sheets together, and that’s why it can’t compete on price with Tesla. Hold on, it seems...BYD prices are actually lower than Tesla’s? Much lower?
Price alone doesn’t really say anything about the giga press. Perhaps BYD’s efficiency could be explained by some of the other few thousand things that go into making a car? What about all the other stamped steel chassis companies BYD is way more efficient than?
Also, production costs are the actual thing that matter for this argument, not price. Tesla has 6x the profit per car of BYD which obviously factors into the higher prices.
Oh, and Tesla is no longer planning single unitary castings for future vehicles?
This is a bit misleading. Tesla doesn’t currently do unitary castings, so this is a suspension of future R&D not changing what they currently do. Importantly, this means they will keep giga casting their chassis for the foreseeable future.
Money is a factor, of course; PR agencies drive a lot of the articles in media. I assume Tesla pays some PR firms and people there presumably decided to push the Giga Press.
You should stop assuming! Tesla spent essentially nothing on marketing until 2023, well after this assumed PR would be taking place. By nothing I mean that the estimate for their marketing spend in 2022 (literally all marketing to include PR if there was any at all) was $175k.
in short, your claim: “The cost of aluminum die casting and stamped steel is, on Tesla’s scale, similar” both seems to miss the entire point and run against literally everything I have seen written about this. You need citations for this claim, I am not going to take your word for it.
Here I would be careful since investments, especially in a particular model generation of welding robots, are depreciated. For forming processes, the depreciation can even extend over three or four model generations. This technological write-off – bear in mind that this is not tax-related – runs over a timeframe of 30 years. For the OEMs that are already using these machines for existing vehicle generations, the use of the new technology makes no sense. On the other hand, thanks to its greenfield approach, Tesla can save itself these typical investments in shell-type construction. In a brownfield, it would be operationally nonsensical not to keep using long depreciated machinery. So, in this situation, I would not support the 20-30% cost savings that were cited.
With die casting, one important aspect is that there is a noticeable reduction in the service life of the die-casting moulds. Due to so-called thermal shock, the rule of thumb is that a die-casting mould is good for 100,000-150,000 shots. By contrast, one forming tool is used to make 5m-6m parts. So, we are talking about a factor of 20 to 30. There is quite clearly a limited volume range for which the casting-intensive solution would be appropriate. To me, aluminium casting holds little appeal for very small and very large volumes. Especially for mass production in the millions, you would need about six or seven of these expensive die-casting moulds. We estimate that the die-casting form for the single part, rear-end of a Tesla would weigh about 80-100 tonnes. This translates to huge costs for handling and the peripheral equipment, in the form of cranes, for example. Die-casting moulds also pose technological obstacles and hazards. The leakage of melted material is cited as one example. The risks of not even being able to operate in some situations are not negligible.
Or the geometry of the frame was insufficiently optimized for vertical shear. I do not understand how you reached this conclusion.
No. If aluminum doesn’t have weak points, it stretches/bends before breaking. The Cybertruck hitch broke off cleanly without stretching. Therefore there was a weak point.
By nothing I mean that the estimate for their marketing spend in 2022 (literally all marketing to include PR if there was any at all) was $175k.
I’m skeptical of that. PR firms don’t report to Vivvix.
I really, really, really did not like this post. I found it to be riddled with bad assumptions, questionable unsupported claims, and critical omissions. I don’t think any of the core arguments survive close scrutiny.
Moreover, I took serious issue with the tone throughout. The first half hand-waves some seriously questionable claims into existence with strong confidence, while the second half opines that everyone who ever thought otherwise is some combination of sycophantic, incurious, brainwashed, or an idiot. I would have appreciated more intellectual humility.
***
My read is that this post totally whiffed on the entire subject of die casting cost savings.
To be clear: the cost savings argument for die casting is little to do with the cost of the chassis itself, it’s mostly an argument about the cost of body assembly.
In an automotive assembly line one of the most labor-intensive, challenging, and expensive steps is the “body shop,” where a car’s structural components are assembled into a “body in white.” Die casting saves time and money by reducing the number of welds, bolts, etc. required to go from components to body. It also cuts down on total weight, waste material from manufacturing a larger number of components, and the number of steps one can introduce tolerance errors.
Here is an example from the Model 3. Switching from traditional assembly to die casting cuts out 169 separate metal parts and 1600 welds. Those costs add up! Look at the difference in estimated variable costs.
in short, your claim: “The cost of aluminum die casting and stamped steel is, on Tesla’s scale, similar” both seems to miss the entire point and run against literally everything I have seen written about this. You need citations for this claim, I am not going to take your word for it.
***
The price thing alone seems like a post invalidating miss, but I was pretty alarmed by the sheer number of other strong assertions made with weak or no supporting evidence. Some of these seemed obviously wrong.
Tesla’s panel gap issues predate the giga press by like a decade and has always been attributed to wide tolerances for all parts and lazy QA (de-prioritized in favor of R&D). I have absolutely no idea how you got to this “understanding.” Citation please?
Or the geometry of the frame was insufficiently optimized for vertical shear. I do not understand how you reached this conclusion.
Price alone doesn’t really say anything about the giga press. Perhaps BYD’s efficiency could be explained by some of the other few thousand things that go into making a car? What about all the other stamped steel chassis companies BYD is way more efficient than?
Also, production costs are the actual thing that matter for this argument, not price. Tesla has 6x the profit per car of BYD which obviously factors into the higher prices.
This is a bit misleading. Tesla doesn’t currently do unitary castings, so this is a suspension of future R&D not changing what they currently do. Importantly, this means they will keep giga casting their chassis for the foreseeable future.
You should stop assuming! Tesla spent essentially nothing on marketing until 2023, well after this assumed PR would be taking place. By nothing I mean that the estimate for their marketing spend in 2022 (literally all marketing to include PR if there was any at all) was $175k.
OK, here’s a citation then: https://www.automotivemanufacturingsolutions.com/casting/forging/megacasting-a-chance-to-rethink-body-manufacturing/42721.article
No. If aluminum doesn’t have weak points, it stretches/bends before breaking. The Cybertruck hitch broke off cleanly without stretching. Therefore there was a weak point.
I’m skeptical of that. PR firms don’t report to Vivvix.