"bob prohaska" wrote in message
news
My original notion was of a large billet with center holes on the
main
axis and every crank throw axis, the question being directed at how
the
throw axis centers were found. Clearly, that's not how it was done.

Thanks to all who replied, I was thinking in the wrong way!

bob prohaska

Clever inventors amd mechanics have been making crankshafts for a very
long time:
https://en.wikipedia.org/wiki/Hierapolis_sawmill
"With the crank and connecting rod system, all elements for
constructing a steam engine (invented in 1712) - Hero's aeolipile
(generating steam power), the cylinder and piston (in metal force
pumps), non-return valves (in water pumps), gearing (in water mills
and clocks) - were known in Roman times."

https://commons.wikimedia.org/wiki/F...nd._Pic_01.jpg

-jsw