Chris from Clickspring has done an amazing amount of work recreating the tools and methods the Greeks would have used, I'm fairly certain he's got all the right answers.<p><a href="https://hackaday.com/2020/12/12/hackers-discovery-changes-understanding-of-the-antikythera-mechanism/" rel="nofollow">https://hackaday.com/2020/12/12/hackers-discovery-changes-un...</a><p>I made gears for 5 years of my life, and they are a pain, but the ancient gears didn't push metallurgy to the limit, expecting decades of continuous service... they had a lot more leeway. Even so, there were a lot of very skilled craftsmen who put in an enormous amount of time building these things, probably in a small shop.