Bernina 530 Manual - Page 54

Bobbin deformed or jamming in case. Needle hole in throat plate damaged by needle, requires repolishing. Faulty Stitches Unsuitable needle. Use needles System 705. Needle blunt or bent. Needle not properly inserted. Long groove must face front. Push needle homecompletely. Inferior, badly polished needle. Cheap needles often tear thread and break easily. This may cause costly damage to throat plate and feed dog. The best needle is the most economical in use. Needle not in proper relation to thread number. Needle Breakage Needle bent. Needle too fine in relation to thread. Needle holding screw not properly tightened, Top thread tension excessive. When the work is pulled towards the operator on completion, the needle often bends. When the needle performs the first stitch subsequently, it fouls the throat plate and breaks. Therefore always pull work away from you from under the presser foot. During sewing, however, the work should not be pulled away from you too hard. 102 Use of cheap thread which is unevenly twisted or even knotty. A single knot on a thread reel may break the needle and even damage the throat plate so that far more expense may ensue than by securing the best possible thread. Slow Operation of Machine Motor too heavily oiled causing collector to be oily. (See Instructions for Lubrication on Page 27.) Call mechanic I Machine (not motor) insufficiently oiled. Thread ends in the shuttle race. Machine blocked by resinified oil. Flush machine with petrol and oil again. In stubborn cases, the machine must be disassembled. If machine has stood in a cold room, it should be placed in a warm room, open, for about one hour so that it will assume room temperature and the oil in the bearings can get liquid again. Work Puckers In most cases this is caused by excessive tension in relation to type of work. When sewing Knitted Goods, never pull work away from you with your hands which will cause work to pucker. It is advantageous, on the contrary, to assist the forward movement by pushing. 103