I made this little robot sometime in mid-2014. The motor case, fuse clips, and most of the underside copper layer are grounded, with small “islands” manually cut clear to carry Vcc. The sides and top of the phenolic board are stained black with Sharpie marker, and the foam tape provides a solid interface with a bit of give to accommodate the underside solder points. The toothbrush belonged to my grandmother; I found it in a travel kit in a piece of very old luggage.