sorry about my English.
pieze B, as you see in photo "pieza_b.jpg, must have one hole for the axi, and other 3 to put in the piece part_E.
i send you a new photo " 3 holes".
in the same pieze, part_B, are 2 holes for part_C and part_D. (2 holes photo). they do not appear in stl file to print.
meshmixer and cura, say that piece have errors