1. See if the pressure of the small clamp is too high. Length of control line of small clamp. If the pressure is too high and the thread is too short, the thread will come out of the pinhole when sewing for the second time.

2. When the tangent electromagnet is working, check whether the big clamp bounces off. If it doesn't bounce off, push the big clip in a little.

3. Whether the position of tangent cam is correct.

4. Whether the handwheel is installed correctly, and whether the sensor at the handwheel is installed correctly or has problems.

5. If the imitation brother is a computer flat car, such as a standard, see if the installation position of the moving knife is too front, or the tangent line is too early.

6. It is a weight copying machine, and whether the installation position of the fixed knife is at the far left.

7. The low line is whether the pressure of the line stopper is too high.