Eli5 How was the first industrial machine made without the precision of machinery?

Question

How do you make a machine that has perfectly flat/plumb/level metal components without the aide of a machine to begin with?

In: 224

Answer 1

I saw a guy cut a thread on a guide rod with nothing but a small file in his hands. Shit worked perfectly. And to be honest, it doesn’t need that much precision to create the rudimentary mass production machinery. Then, so long as your initial machinery is consistent, you can use it to manufacture more precise instruments, and so on and so forth. This is how we’re not stuck on some arbitrary level of precision and keep making more precise tools using their previous, less precise iterations.