... Best credit. T:86-23-67608685 F:67608618 work principium:step motor is controlled by computer and mark pin moves by the ... on. mark object:chassis of auto and motorcycle, vehicle frame, motor, nameplate, piston, carburetor, shock absorber, cylinder mat,transmission case, ... gear wheel and so on;aircraft motor, motor vane, air workpiece and so on;valve, ironware, reamer, ...