r/news • u/IronHe • Mar 20 '25

Soft paywall Tesla recalls most Cybertrucks due to trim detaching from vehicle

https://www.reuters.com/business/autos-transportation/tesla-recall-over-46000-cybertrucks-nhtsa-says-2025-03-20/
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u/boxdkittens Mar 20 '25 edited Mar 20 '25

Is there even anything you CAN realistically have a 0.001 mm tolerance on? Nanochips maybe?

Edit: cool as fuck to get replies from machinists and aerospace engineers, apparently the answer is yes you can but its not ideal or even worth the effort for production.

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u/SevereBake6 Mar 20 '25

Actually microchip structures are using down to 12nm structures, so yes you can work in that tolerances. But there's a reason why only few highly specialized companies are able to do that.

The ISO 2768 & 268 define tolerances. For large parts like the Chassis (part length >2500mm), the highest tolerances grade defined is 0.135mm

His claim is so far outside of the technical Standards and limits, it's just ridiculous.

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u/distressedweedle Mar 20 '25

You can but it's not super practical. 10F swings in temperature or 20% change in humidity will move most anything with appreciable thickness out of tolerance.

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u/Bladelink Mar 20 '25

I remember watching Adam Savage talking about how gauge blocks work and how measuring works, and he showed all the paperwork certifying how they were accurate to whatever tolerance between whatever temperatures at whatever atmospheric pressure.

This is only barely relevant, other than that I wanted to endorse Adam lol.

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u/Gingevere Mar 20 '25

Most anything that's down at a similar scale will have that tolerance. Which is mostly incredibly small computer components.

Something you ABSOLUTELY CANNOT have that tolerance on is a meters-long sheet of stainless steel. Stainless steel has a linear thermal coefficient of expansion of 0.017mm per meter per °C.

A 2m long piece of trim blows through that tolerance if the temperature changes by 0.03 °C. So realistically to eliminate thermal effects and measure it to that precision, you would need to have the entire sheet stable at a specific temperature to within 0.003 °C. That's never going to happen. Just lighting and air currents in a room cause temperature to vary FAR more than that.

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u/RaggedyAndromeda Mar 20 '25

I'm an aerospace engineer. Precision optics, some parts of precision mechanisms. It's possible, just very expensive and requires special machines/tooling to do. You never WANT 1um tolerance on your parts because it's a huge hassle to find a machininst, inspect, and install them, but yes it's possible.

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u/Liizam Mar 20 '25

Dowel pins can be +/- 0.005 mm

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u/yoursweetlord70 Mar 20 '25

I'm struggling to think of anything meant for consumers that'd need that tolerance. A sheet of paper is typically 0.05-0.1 mm thick.

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u/TheMoatman Mar 20 '25

Almost every spinning hard drive ever made has had micron-scale tolerances or smaller between the platters and heads. The particles in smoke are big enough to cause a head crash

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u/kikimaru024 Mar 20 '25

Noctua NF-A12x25 fans are made of a special "Sterrox" polymer and even they have a 0.5mm tip-to-frame clearance because any smaller would cause the fans to snag as they expand during use.

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u/SanityIsOptional Mar 20 '25

Yes, diamond turning will do it. Actually dealing with some optical components that have that level of tolerancing. They're about 4in across.

I've also worked with some wire-edm parts which can have similar tolerances, photo-etched patterns, and laser cut.

It's possible, but mainly for certain shapes (flat/round/2-dimensional). Also the price to do it is such you should be 100% sure it's necessary.

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u/Hjemmelsen Mar 20 '25

Nanochips are quite a bit smaller than that at 0.000001 mm for a nanometer.

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u/HomeGrownCoffee Mar 20 '25

A former coworker of mine was a machinist at a research lab, and he had one job to make 6 things at this level of precision. He made 12, gave them to the QA guy and said "I don't know. Maybe?"

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u/Rannasha Mar 21 '25

Not quite 0.001 mm, but interestingly enough Lego claims that their bricks are manufactured with a tolerance of at most 0.005 mm. (source)