Depends on what it is. Some things like ball bearings need to be precise in order to work efficiently, but car body panels definitely do not need to be that precise. Pretty much nothing on a car needs to be within 10 microns.
You also have fun effects due to temperature, humidity, vibrations, heat radiation, etc. This means that large sheets produced in those precisions will still bend and all that, making the smoothness a bit absurd.
That said I could imagine that he mistranslated something his usability haptic researchers did tell him, that hands can detect irregularities up to 9 microns. Those numbers are relevant for how smooth surfaces have to be that people regularly touch. Still even in that most generous case it is a bit absurd, especially when we see Tesla's shoddy current construction.
Also less reliable, "back in the old days" mechanical products had pretty loose tolerances, and the entire design was based on tolerating the loose tolerances. That way shit never breaks when it bumps around and is used for years. "High precision" is both wasteful and unneccessary, since once one thing goes wrong it can fuck up like 5 more things instantly.
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Depends on what it is. Some things like ball bearings need to be precise in order to work efficiently, but car body panels definitely do not need to be that precise. Pretty much nothing on a car needs to be within 10 microns.
You also have fun effects due to temperature, humidity, vibrations, heat radiation, etc. This means that large sheets produced in those precisions will still bend and all that, making the smoothness a bit absurd.
That said I could imagine that he mistranslated something his usability haptic researchers did tell him, that hands can detect irregularities up to 9 microns. Those numbers are relevant for how smooth surfaces have to be that people regularly touch. Still even in that most generous case it is a bit absurd, especially when we see Tesla's shoddy current construction.
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deleted by creator
Also less reliable, "back in the old days" mechanical products had pretty loose tolerances, and the entire design was based on tolerating the loose tolerances. That way shit never breaks when it bumps around and is used for years. "High precision" is both wasteful and unneccessary, since once one thing goes wrong it can fuck up like 5 more things instantly.