18aa367c_ooting_Sewing_Machine_Problems__Symptom
[Root Cause] A thin needle was used for sewing a heavy weight material. Needle has not been fully inserted into needle bar. Needle clamp screw is loose. Presser foot is not correct one. Presser foot is loose. Pulling on fabric as you sew. [Corrective Action] Use correct size needle. Properly insert needle. Securely tighten needle clamp screw. Use correct presser foot. Reset presser foot. Do not pull fabric, guide it gently. [Symptom] 
Needle breaks.
Troubleshooting Sewing Machine Problems
Symptom