I am pretty sure that the brown wires are ground and should go toward the same side of the PCB as the USB and power plugs. But that's only an educated guess. It would be nice if step 10 of the assembly instructions indicated this.
Good point, we'll add this to the instructions and the next version of the PCB. However your correct the brown wire (ground) should be the closest to the "back" of the piccolo for all three servo's.
I am pretty sure that the brown wires are ground and should go toward the same side of the PCB as the USB and power plugs. But that's only an educated guess. It would be nice if step 10 of the assembly instructions indicated this.