1. Fault characteristics: The upper thread is floating.
Cause of failure: The tensioner pressure is too small.
Treatment method: Tighten the clamp thread to increase the tension of the cotton thread.
2. Fault characteristics: The bottom line is floating.
Cause of failure: The bobbin spring is too loose.
Solution: Tighten the bobbin spring screw to increase the tension of the bottom thread.
Treatment method: Tighten the pressure adjusting screw.
4. Fault characteristics: Each needle under the sewing material has a thread cover in the shape of a towel thread cover.
Cause of failure: The action of cloth feeding and thread take-up is inconsistent, and the action of cloth feeding is fast.
Solution: Adjust the cloth feeding cam screw to make the cloth feeding and thread take-up action in harmony.
5. Fault characteristics: The stitches do not meet the requirements
Causes of failure: The machine thread is not fully pulled into the sensor; the threading method is wrong; the bobbin case is wrong; the size of the bobbin cap does not match.
Solution: fully pull the machine thread into the sensor; thread the thread correctly; correct the bobbin case; use a bobbin cap of the same size.