For this project i decided to used 5/5mil traces for the windings on 4-layers, adding to around 140 turns. This design choice makes the coils much bigger than the ones I used for my micro PCB motor (https://hackaday.io/project/39494-pcb-motor) which had 4/4mil traces and around 40 turns.

The bellow 26.7 x 258.2 mm 4-layer pcb with the 12 coils was designed. Thank you oshpark.com for supporting this project.