... 23-67608685 F:67608618 work principium:step motor is controlled by computer and mark pin moves by the preconcerted track ... surface, circle pipe axes mark and so on. mark object:chassis of auto and motorcycle, vehicle frame, motor, nameplate, piston, carburetor, ... , cylinder mat,transmission case, gear wheel and so on;aircraft motor, motor vane, air workpiece and so on;valve, ironware, reamer, saw ...