CNC machines question (computer numerically control)?

Question

What can CNC machines that is virtually impossible for human controlled machines to do?

Answer 1

Not much.  Off the top of my head turn non-circular part with a single point tool.  That would be make ovals on a lathe.  Maybe build those moving cavity pumps.

In almost every case it's not that a job is impossible without a CNC it just take way longer to set up and run or require really expensive tooling.  If you really want to you can mill internal threads or complex curves on manual machines but a CNC will do it way faster.

Answer 2

higher accuracy

more efficient, faster

making 3D curves with precision