Issue link: https://docs.hic.us/i/445658
216 Chapter 11 Troubleshooting Needle breakage Bad finishing of sewing Cause Corrective Action A clearance between needle and hook point of rotary hook is not suitable. Perform adjustment so that a clearance becomes 0.1 to 0.3 mm. Bad needle location Perform adjustment so that needle is located to the center of needle hole of needle plate. Play of needle bar case (in right and left direction) is big. Adjust. Abrasion of needle catcher of rotary hook Replace the rotary hook. The floor vibrates. Change installation site of the machine. There is a play on the fringe of frame. Adjust the play. Replace the part. Cause Corrective Action There is a play on the fringe of frame. Adjust the play. Replace the part. Abrasion/breakage of neighboring parts of take- up lever drive and/or needle bar drive Replace the part. Bad take-up lever timing Adjust start-up timing. Belt tension of drive system is too strong or too weak. Adjust. QS04