An on-car disc brake lathe system (30) for resurfacing a brake disc of a vehicle brake assembly includes a lathe body (34) with a driving motor (32), a cutting head (36) operably attached to the lathe body, and a drive shaft (68). The system also includes an alignment system (50) having an electronic controller (600), input and output adaptors (66, 82) configured to rotate with the drive shaft, one or more adjustment discs (90, 92), and an adjustment mechanism (94, 96).