Carriage for Heacent Prusa i3 standart/E3D cyclop/chimera

Carriage for Heacent Prusa i3. It uses makerbot-like direct extruder. The original carriage was made from PLA plastic and it has temperature deformation while printing ABS. I have to "reverse engineering" another one.
Vitamins: 2? M3x15 screw, 2x M3x30 screw or so, 8x M3 nuts.
WARNING! You must to pause the printing and drop M3 nuts - 7 in the carriage and 1 in the "belt holder part1". Nuts places are numerated at the photo.

UPD 24.02.2017 Add no inner nuts version, add E3D cyclop/chim