Closeup of Robot Achilles' left foot.  The heavy-duty
military grade needle-bearing universal joint (modified)
is clearly visible.  Modifications include weight/size
reduction and addition of nuts welded on both ends
into which bolt the lower foot and upper leg.  Model
RC light weight aluminum rods connect servos to the foot.
Except for U-Joint, Servos and nuts/bolts, all
components are made of aluminum.