[GingisK]

Cutting perfect concentric deep-groove circles by hand?

They were smart enough to use a fly wheel on the drill. I'd expect them to be smart enough to make a fly cutter or trepan-like rosette cutter.

[ProtectOurFreedom]

Yes, it would be a small step to mount a cutter on that flywheel.

[Vaduz]

Archimedes raps box