How did they made these ...in XVI century?

[mklotz]

DIYSwede I already knew the video featured in that post. And indeed was something that followed the same path I had in thinking that the lathe was the machine that made everything. Indeed, inspired by the introduction to a book about a project for a DIY lathe out of concrete (sorry I forgot the title). That's also why I started to make my own lathe. But what I ask here is something different. Look at the part enhanced by the red circles. Those are not made with a lathe. Maybe a milling machine, but there was milling machines at the time? Still, some part really intrigue me. I am not a machinist, so I wonder how to make those "hexagoned eggs" (well I really don't know how to call those parts) circled in D and C.

One way to make duplicate parts with matching symmetry is to use filing buttons.

A Google search will provide much to read on the topic so I'll offer only a short summary here...

The desired pattern is formed in a metal that can be hardened. After hardening, this pattern is clamped to the workpiece. The worker files the workpiece down to the pattern. When he has matched an area of the workpiece to the shape of the pattern, his file will "skate" on the hardened pattern, signalling that he's filed enough at that location. The worker shifts his attention to another area and repeats the process. When done, the hand-filed workpiece is a near perfect copy of the pattern.

[Claudio HG]

One way to make duplicate parts with matching symmetry is to use filing buttons.

Yes, that is a clever method. Didn't know those, let's say template, were named filing buttons. Thanks, I learned something new.
That seems to be a solution for small parts though, but some parts that you can see in the pictures are quite big. However I just realized that those parts could have been made from casts, and then filed or grinded down to the desired dimension and finishing appearence.

Anyway, I don't know you guys, but I am really fascinated by those old machines and how people did them. I got lost as in a rabbit hole in every museum I visited: London, München, Paris, Milano. The first two are IMHO the absolute best, but they are so large that one would need days to visit them throughly.