Calibrating the needle bar swing is a critical step in coverstitch machine operation, as it directly affects stitch quality and machine stability. First, check whether the needle bar swing amplitude is within the standard range (typically 2–4 mm), which can be measured using the scale markings on the machine body or with a dedicated measuring tool. If the amplitude is too large or too small, make fine adjustments using the adjustment screw: turning it clockwise reduces the swing, while turning it counterclockwise increases it.
This adjustment should be coordinated with the feed dog height setting to ensure synchronized movement between the needle bar and the feed dogs, thereby preventing loose stitches or abnormal noise. In addition, regular calibration helps reduce the risk of needle plate wear and lays a solid foundation for subsequent adjustments when working with elastic fabrics. During operation, it is recommended to refer to the equipment manual and ensure smooth, controlled movements to improve overall sewing efficiency.