Hello, in addition to ordinary sewing machines, clothing enterprises usually need to use some special decorative sewing machines, such as zigzag sewing machines, to meet the individual needs of the modern clothing market. However, the fracture of section line and bottom line is also a common problem of zigzag sewing machine in garment production. According to the actual operation experience of several maintenance workers, some related maintenance methods of zigzag sewing machine section line and bottom line fracture are classified and sorted out (the following analysis will talk about the cause of the failure first, then the treatment method), hoping to provide you with useful help. 1. The stitching strength is too poor; Only need to replace the suture with better strength and quality; 2. The pressure of the top thread and the bottom thread is adjusted too tightly, causing the suture to be scratched or broken; We can slowly loosen the thread clamping nut and bobbin screw, and adjust the upper or lower thread accordingly; 3. The threading sequence is incorrect or the needle is bent; Replace the new needle and thread the needle in the correct order; 4. The needle hole edge of the machine needle has acute angle or needle groove hair; Use or replace a new needle after polishing the pinhole; 5. The rotating shuttle is not stable or the position is not installed correctly; Adjust the position of the shuttle according to the standard; 6. The hook of the hook is damaged or the hook line is too fast or too slow; Polishing the hook or replacing the hook, and adjusting the hook time of the hook; 7. The needle hole is rough or the needle slot of the needle plate is damaged; Grinding and polishing the needle groove of the coarse pinhole needle plate; 8. The main shaft is too big or the concentricity of the main shaft is not good, so the operation is not flexible; Properly improve the cooperation between shuttle and shuttle core; 9. The bottom thread is too full, too loose and too messy, which makes the bottom thread not smooth in the sewing process and causes thread breakage; The winding machine can be reformed to make the winding on the spool uniform, compact and tidy; 10. The position of the feed tooth is too low, and the distance between the quick opening at the bottom of the feed tooth and the outlet of the bobbin thread is too small, resulting in contact friction between the bobbin thread and the quick opening at the bottom of the tooth; Adjust the height position of the feed tooth reasonably, or fall into the feed tooth, and polish the bottom of the tooth with fine sand to quickly open it; 1 1. The shuttle skin and the shuttle shell are not well matched, and there is a gap in the middle, so the outlet tension is uneven; Adjust the fit clearance between the shuttle skin and the shuttle shell reasonably so that the tension of the bobbin thread will not change.