This 3D printed bottom bracket attaches to chassis platform with four M3 screws and provides mounting holes for the H-bridge motor controller, the Arduino and the Raspberry Pi. Four M3 spacers attached onto the top to provide clearance for the circuit boards and connectors.
You can download the .stl or Freecad files here;
Don't have a 3D printer? If you are in the UK you cano order one from civrays via makexyz.
Please check out the other 3D parts;