The reason mechanisms like this are so mind blowing is because one simple has no precious artifacts from this time period which would make us aware of the fact

The reason mechanisms like this are so mind blowing is because one simple has no precious artifacts from this time period which would make us aware of the fact that they had the technology to make such objects. And by technology I don’t mean modern day CNC machines. However we know that sophisticated mechanical work began again in The 1400s with various clock makers. However these still typically had a variety of tools and measuring instruments. It is not immediate obvious that ancient Greeks would have variety of files, calipers, lathes etc which appropriate techniques developed to use them to make sophisticated machinery.