Micro motor of steering gear - driven by pure motor rather than cylinder to eliminate in- stability of air supply and pressure Special positioning mechanism - the six waiting positions and the first bobbin core are equipped with independent positioning pins to ensure the stability of grasping Underthread detection mechanism - real time detection and monitoring of the bobbin thread allowance on the winding column of the first shuttle core,parameter can be set for margin value Signal prompt lamp - the visual signal light can be used for warning