to amplify Hansel's comment, note that arm with the hole all the way through is not symmetrical. in needs to be assembled so that the slightly taller hub is next to the bearing. Otherwise, the bearing will rub on the side of the hub support when assembled. Be sure you get this figured out before you assemble because it can be very hard to get the pieces back apart if you do it wrong. The insert posts will break if you are not careful.
12/17/17 - STOP! read ahead to step 56! on my version of the board, there are three pre-installed headers, one for each fan connector. There is no need to cut or splice the part fans.
to amplify Hansel's comment, note that arm with the hole all the way through is not symmetrical. in needs to be assembled so that the slightly taller hub is next to the bearing. Otherwise, the bearing will rub on the side of the hub support when assembled. Be sure you get this figured out before you assemble because it can be very hard to get the pieces back apart if you do it wrong. The insert posts will break if you are not careful.
12/17/17 - STOP! read ahead to step 56! on my version of the board, there are three pre-installed headers, one for each fan connector. There is no need to cut or splice the part fans.
12/17/17 - the printed circuit board has changed slightly. There are now four fan connectors pre-soldered to the board
be careful not to scrape the kapton tape off the thermal fuse as you are sliding it into place against the sharp cooling fins