Precision machining of propeller blades; Subhuman III Human Powered Record Challenger.
This HPV sub featured
two, twin blade, counter rotating propellers of an extremely sophisticated
design. Blades were machined from 6061-T6 billets. The blades fit into a clamped
retention system in the hubs. Also of interest, the entire propeller assembly
including fins could be pivoted to provide vectored thrust for directional