Reasons for breaking of the needle thread



  • The thread path is bruised
  •  High-grade thread is not used for needle thread
  •  Wrong threading: threading through the thread take-upspring neglected
  •  Needle size too fine
  • Wrong timing of the sewing hoo



Reasons for the stitches to float and measures to prevent the thread from slipping out of bobbin case 

  • The main reason is either the tension of the bobbin thread is too weak or the bobbin thread slips out from the bobbin case. When polyester or nylon threads are used, the bobbin thread often slips out. In such a case, lessen the amount of winding thread on the bobbin. Also, if some lubricant such as vaseline is applied between the bobbin case shaft and the bobbin case slit, this defect will be eliminated

Reason for wobbling stitches immediately after the first barred end is finished
  • This defect appears when the starting action of the tension disc No. 2 is a bit too late at the first barred end and also when the "floating" amount of the tension disc No. 2 is too great

Slipping out of the needle thread

  • This defect occurs when the grasping power of the needle thread trimmer blades is inadequate

Reasons for wobbling stitches at the start 

  • The height of the needle thread trimmer blades too high
  • The angle of the tension release tripping segment No. 2 installed wrong. Adjust it so that the tension releasing time at the start of sewing is shortened.