2. Skipped stitches: 1. Needle bent 2. Needle set with long groove turned to wrong side 3. Needle too high or too low in the needle bar 4. Needle too small 5. Needle threaded from the worng side 6. Excess oil on shuttle.

6. Needle breaking: 1. Incorrect size of needle for thread and fabric 2. Needle blunt 3. Pulling of material while stitching 4. Presser foot incorrectly set 5. Crossing a thick seam using a too small needle.