Job shop work... it takes 2-4 hours to set up a machine to make a type of gear, and anywhere from 30 minutes to 2 days per gear depending on how big they are. I made almost all the drive bandwheel and pinion bevel gears for Marvel 18" Bandsaws for 4 years, along with a variety of other bevels, along with some spur and helical gears.
It turns out that gears have a rolling contact surface, never sliding (unless you did it wrong), which is why they can last decades. I learned a ton of interesting things about small scale manufacturing. I want to make them on the small scale (4" or less) as a hobby, once I get employed again.
