[blindguy]

The reason the hex peices are off is because of the plastic coupling. Near that plastic thing in the middle the edges warp out a little, and not the same on all sides. the way our team(me) resovled this problem what to remove the plastic from the center of the coupling(so you could shove a hex shaft all the way threw). Then I stuck the part that connects to the motor in so all the hex part was hidden. Now the other one will end up sticking a little bit further out but its ok cuz what you just did is shift the coupling over a bit.