Originally Posted by
Cecilia S.
So, not having seen in person a hand crank,
http://www.youtube.com/watch?v=D9DAZTh8744
Here you go. Generally three stitches per crank rotation. They're great for children to learn sewing (all the old children's machines were HC).
EDIT: Motor boss is the raised bit the motor is mounted on and can slide up and down. Cranks are mounted on the same boss