I saw some Koenigsegg video showing that they have molds and they papier mache pieces of carbon fiber sheets on top, to give it the shape they need and then bake it. What I don’t get is how is it possible to get any sort of precision using this method. For example, wouldn’t wheels have messed up weight distribution, since you can’t evenly apply carbon pieces to the mold?
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Typically the carbon fiber would be vacuum sealed against the mold, meaning that it follows the exact shape of the mold very well. As for getting a good distribution, carbon fiber is very thin so by applying multiple layers you can precisely balance out the wheels.
The molds are the key part in the process.
Each mold is measured with metrology tools, either they measure sample points in the mold or use 3d scanning devices ( faro focus, leica scanners…)
They then compare the measurements with the theoretical 3d model of the mold.
When mold is within the approved specification, they will be able to lay the carbon sheets according to the engineer plans.
After the moulding is done, they will do the same tests on the part.
Serendipitously enough, Christian Von Koenigsegg explains what they do in the video: https://www.youtube.com/watch?v=PGGiuaQwcd8&t=211s
TL;DW: They put a little bit of extra carbon fibre on the spoke opposite of the metal valve to “pre-balance” the wheel. Since tyres themselves have some innate imbalance, they position the tyre on the rim in a way that the wheel and tyre balance each other out.
Outside of that specific case, you can always grind and file carbon fibre parts after they’ve been baked to get them just right if need be.