structural:summarization, information:classification
Artisanal

The teeth of antique or artisanal gears that were cut by hand from sheet material, like those in the Antikhytera mechanism, generally had simple profiles, such as triangles. The teeth of larger gears — such as used in windmills — were usually pegs with simple shapes like cylinders, parallelepipeds, or triangular prisms inserted into a smooth wooden or metal wheel; or were holes with equally simple shapes cut into such a wheel.

Because of their sub-optimal profile, the effective gear ratio of such artisanal matching gears was not constant, but fluctuated over each tooth cycle, resulting in vibrations, noise, and accelerated wear.