Видео с ютуба Invent Gear

The History of Gears

Making Internal Gears - It Took Longer Than I Thought (Ring Gears)

How to make gear motor at home

21Days Machining Process of 3Ton Industrial Gear with 100yrs old Technology

Watchmaking: Machining a Watch Gear

Gears! - But Were Afraid To Ask (MiniLathe)