I. Wire Break
Reason: There are burrs on the needle plate or pinhole.
Method: If the broken end is horsetail, it may be burr on the crossing hook, excessive tightness of the clamp and excessive amount of the spring. If the broken wire head is cut, it may be that the position of the mechanical structure of the machine has changed, the parts have not been disassembled according to the original position in the disassembly process, the parts have been damaged by the impact of the broken needle and other parts, and the edges of the parts have burrs, etc. If one or two strands of broken yarn occur on one thread, it may be due to the high foot press height.
2. Jumping Line
Reasons: The spindle and needle are not adjusted in place;
Method: On the premise of correctly installing the machine needle, the machine needle moves from top to bottom and the spindle rotates. When the needle is lowered to a very low position, the spindle tip should be within the range of 14 18 and 10 12 mm from the center of the needle. That is to say, when the needle rod goes down to a very low level, the distance between the needle tip and the needle tip is 3.5-4MM, and the needle rod rises 2.2MM, the needle tip reaches the center of the needle, and the distance between the needle tip and the needle hole is 1.2-1.5MM.
3. Broken needle
Reason: Machine needle touches metal parts such as spindle.
Method: Whether the machine needle and the hook tip of the spindle touch or not. Whether the machine needle is too thin or the quilt is too thick. Whether the foot press height is too low, so that the machine needle and foot press rub. Check nylon gear wear and screw loosening. Check if the synchronous pulley is loose. Check the needle plate, there is no broken needle marks on the spindle.