Assembly video needs work

[Aztecphoenix]

Not sure about the crank arm, where did you see it?

If you look at the printout for the scanner just below the encoder disk is a thick black line if you read the text below that it is instructions for bending wire for a crank arm.

[Anuvin]

Sure enough. You can even see that Nathan made the crank arm. It it for a pulley system. I am not sure, but I suspect you will cut out a disk from cardboard and poke the crank arm through. Then run some fishing line around both disks and crank to spin your object. Does that make sense? Only thing I can think of for the fishing line he mentions.