1. If one stitch is skipped after several stitches, it may be that the shuttle is severely worn, causing the tip of the shuttle to be too blunt, or the needle of the sewing machine is too high/too low.
Solution: Replace the shuttle with a new one, adjust the height of the needle bar or the height of the needle, and re-align the needle.
2. The bobbin thread cannot be threaded and the needle skips. It may be that the shuttle thread is too short, the shuttle thread is caught in the shuttle door, the needle is too high, and the shuttle swing cannot catch the thread loop.
Solution: lengthen the shuttle thread and check whether the bottom thread is caught. Looseness of the fastening screw on the needle bar connecting shaft will cause the needle bar to move up, causing the needle to be too high, and the shuttle swing cannot catch the thread loop. Therefore, the height of the needle bar should be adjusted, and the fastening screw should be tightened after re-aligning the needle.
3. If the jumper is caused by the movement of the needle bar, the reason may be that the needle bar hole or the needle bar is worn, the screw of the needle bar connecting hole is loose, and the needle bar is displaced.
Solution: replace the needle bar sleeve, or replace the needle bar with a new one and re-align the needle, and tighten the fastening screw.
4. When sewing thick jumpers or thin jumpers, it may be that the needle plate of the sewing machine is severely worn, the needle is too thick, the bottom of the presser foot is worn or the pressure of the presser foot is too low.
Solution: Replace with a new needle plate, replace with a thinner needle, replace the presser foot or adjust to an appropriate pressure of the presser foot.
5. If the stitches are skipping continuously, it may be because the quality of the needle is poor or the needle is bent and the loop cannot be produced normally; Improper fit between the two parts; long-term use of shuttle pendulum, shuttle bed and other parts are seriously worn and other reasons.
Treatment method: replace qualified machine needles or straighter machine needles; adjust the height of the machine needles so that the sewing material, suture and machine needles cooperate with each other; regularly check the shuttle shuttle bed and other parts, and replace the severely worn parts in time..