6 | Clark Manufacturing
is quite unique to Traverse City, Michigan.
This was the same Northern Michigan com-
munity where industry innovators John T.
Parsons and Frank Stulen developed the first
numerically-controlled device utilized in
machining the accurate curvature of rotors
crucial in the manufacturing of helicopters.
In an effort to exact stress calculations in the
production of rotors, Stulen initially experi-
mented with a punched-card machine that
could generate a 17-point outline. Parsons
later expanded on that approach by partner-
ing with MIT to develop a more sophisticat-
ed, fully-automated tool, but these processes