Inverted/Reversed + Centered Z axis Tevo Tarantula

Why this change?
Lowering the motor from the Z axis eliminates unbalance in height and thus reduces vibration throughout the printer. In addition, the plastic support of this axis was not very rigid and thus reduced precision.
In order to avoid applying a moment to the rising profiles and thus have a balanced structure, the Z axis must coincide with the centre of gravity of the part supported by this axis.
By applying the equation to find the centre of gravity for a system of solids (http://h