06-23-2010, 08:15 PM
I would imagine most of that central rib is hollow, up to about the 10-11cm mark, and then maybe solid for the last section, I assume the blades are then welded to the central midrib? If its hollow all the way up it would be very difficult to weld the blades without damaging the midrib, so I would think the last bit is solid.
Stuart
