The design for Tesla’s long-delayed, sci-fi-inspired Cybertruck was first unveiled in November 2019, but a company-wide email sent by Elon Musk in August 2023 implies he’s worried about “precision” in manufacturing the trapezoidal pickup truck, which demands “straight edges.”
Musk’s memo reports that that “due to the nature of Cybertruck, which is made of bright metal with mostly straight edges, any dimensional variation shows up like a sore thumb. All parts for this vehicle, whether internal or from suppliers, need to be designed and built to sub-10-micron accuracy. That means all part dimensions need to be to the third decimal place in millimeters and tolerances need to be specified in single digit microns. If LEGO and soda cans, which are very low cost, can do this, so can we. Precision predicates perfectionism.”
Why are the Cybertruck’s straight, angular edges suffering from faulty manufacturing? The small veteran band of brother engineers and pressmen who have worked in a high-volume automotive shop know the answer. Stainless steel is hell on tools, and the very expensive dies used to form the curvy, sexy exterior steel panels of contemporary consumer vehicles.
In fact, even with ordinary steel, you generally cannot form a complex, deep, curved surface in just one pass. It requires a journey for the sheet metal through a series of (aptly named “progressive” dies) to form the shape without tearing the steel (Yes, Virginia, stamping presses can tear steel even better than Superman can).
Young designers and engineers, whose brows require constant mopping, are the bane of the tool and die shops since they love curves. Frequently over the history of the modern exterior automotive design — since Chrysler’s airflow in the 1930s — it is the engineering managers who scream at the “artists” that “we’re making Chevys, not Bentleys. We can’t afford the dies or the scrap rates to make this unit’s exterior!”
But the use of much better mass-producible steels — thanks to the advances made in World War II and hardened die surfaces — have allowed us to have seen the stunning Jaguar XKE of yore as well as the cookie-cutter but curvy exterior SUVs of today.
But, since Elon Musk doesn’t tolerate such abuse (i.e., common sense and legacy engineering), we have “bent” metal, not curved metal exterior panels exiting the bending dies. These are much cheaper than the progressive forming dies needed for a sexy shape, and when they wear out of specification, they are much cheaper to replace than the progressive die set.
Don’t get me started on fit and finish, the only part of a car that 99.9% of owners ever notice. Tesla is terrible in this department. I can just imagine a final line inspector at a GM or Ford assembly plant screaming out, “Who, the f**k let this unit get this far?” Many, many times have I seen an assembly line worker use a crowbar to “adjust” the fit of a door, but that’s a story for another time.
Having briefly discussed the manufacturing and metal issues of the Cybertruck’s appearance, let’s now get to the exterior finish, i.e., the “paint,” and the practical problems with using a tungsten carbide exterior coating.
Henry Wadsworth Longfellow said, “Great is the art of beginning, but greater is the art of ending.” In my educated opinion, I believe that Cybertruck will end before it ever really begins. Why?
Automakers cannot paint stainless steel with a durable coating in any affordable way known to contemporary paint engineering, which is why automakers do not paint the raw steel exterior panels on contemporary cars and trucks. You paint onto a coating, pre-applied on them after they’ve been formed that the paint adheres to.
It’s not quite true that stainless steel does not “rust.” It’s just that the surface oxidation (rusting) of stainless steel is such that once a thin “protective” layer of “rust” is formed, it prevents further penetration of moisture into the surface so that only a green patina (in the case of nickel, stainless steel) ultimately forms.
The protective patina, by the way, is friable (i.e., it can be broken through by being scratched). Each time that happens, a new patina will form, which gives old stainless-steel panels a blotchy look.
As a consultant on painting technology to DeLorean Motor Company in the early 1980s, my most vivid memory of John DeLorean was the final interview that I and my partner, an ex-Ford design studio engineering manager, had with him and his CEO, who was a former general manager of GM’s Pontiac division. My partner, who was eight years old when World War II ended and had vivid stories of the firebombing of his hometown, Hamburg, Germany, is a no-nonsense guy who drove a Jaguar XKE that he called “baby” and whose refrigerator’s sole purpose was to host a bottle of gin.
He told Delorean, “You can’t paint stainless steel. It’s natural patina forms and prohibits any uniform undercoating so that the top coat (what the customer can see) simply flakes off.” John Delorean, who had movie-star good looks, screamed for us to get out of his office and told his cowering CEO to find some competent engineers. I have always wondered if he was coked up at the time, but I’ll never know.
Today, of course, paint technology has advanced over what it was in 1980, right? I leave this question open to the brave paint engineers who will risk the wrath of Mr. Musk.
However, the notion that tungsten carbide coating can resist “scratches” on the Cybertruck’s surface (a/k/a patina) needs to be reevaluated. First, how would you coat the entire exterior? Tungsten carbide can only be created at very high temperatures, too high even for an in-line process during exterior body panel assembly. And, if you coat the panels before final assembly, the coating will flake off at the edges and surely be scratched off and/or penetrated during those operations (It is not like Superman’s costume, impervious!).
But let’s assume for the sake of argument that the automaker is somehow coating the car with a continuous tungsten carbide film. What would be the exterior color? Grey, metallic? I don’t know. But what I do know is that as soon as the coating becomes scratched or marred, the underlying stainless-steel patina forms, which is what gives the vehicle’s exterior a mottled look of greenish islands among the grey.
I just had a vision of a tungsten carbide coating machine. It would feature a variable source, and the shape of the source must closely follow the shape of the target being coated unless it is planned to react with the components of the coating at the surface to be coated. This would require a NASA-type installation. There would also be a jig to hold and transport the piece to be coated. No such installations have been built, so far as I know, in the history of this planet for the mass production of large-coated parts. Did I mention the temperature of formation of tungsten carbide? Ask Elon Musk about this. He’s got a master’s degree in solid-state materials from Stanford.
Ignoring the above, we still have a truck that looks like “Nude, descending a staircase” (look it up) come to life. It would have been a big hit in 1923 when car makers were experimenting with shapes to wean customers from Ford’s one available design.
All the (un)learned analysts share Tesla’s corporate margins even when we don’t want to hear about them. Can anyone discuss the actual costs of building a Cybertruck? Never mind corporate margins. What’s the margin going to be for the Cybertruck?
Henry Ford, when asked in 1915 what colors the Model T was available in, said, “Any color, as long as it’s black.”
Elon Musk should answer the same question with, “Any color you want, at least until you leave the dealership.”
Notwithstanding my snarky attitude, it’s not about color, it’s about brand loyalty. It’s going to be hard to wean loyal customers from their Detroit iron.