① Irregular movement of clothing
In the process of using sewing machines to sew clothing, sometimes the clothing material moves at an uneven speed and the stitch length is short and irregular. The cloth is moved forward by the cooperation of the feeding teeth and the presser foot. Therefore, when the cloth has the above-mentioned irregular movement, it can be concluded that the teeth and presser foot are malfunctioning or the pressure is improperly adjusted. For example, the presser foot pressure is too low. If the fabric is not pressed tightly, it will cause irregular movement. At this time, just turn the pressure regulating screw down to compress the clothes. If the presser foot is too high to hold the clothing material, it will cause the clothing material to move randomly or not at all. When adjusting, first raise the presser foot wrench, loosen the guide frame screw, and then move the presser foot bar from top to bottom to make After adjusting the distance between the presser foot and the needle board to a height of 7-8 mm, tighten the screws immediately before driving.
Another reason is that the tooth screws are loose, causing the teeth to shake from side to side during operation, so that the cloth cannot move forward regularly. The treatment method is to remove the needle plate. Tighten the two teeth screws. After tightening, install the needle plate and check whether the two sides of the teeth rub against the edge of the needle plate groove. If there is friction, it will cause noise and machine weight. At this time, only remove the needle plate and loosen the teeth screws. Adjust the position of the teeth to the middle of the needle plate groove, tighten the teeth screws, and then install the needle plate.
②The clothing does not move forward
The movement of the cloth is entirely transported by the teeth. When the clothes don't move at all, the only way to find faults on the teeth. If the tooth position is too low, the cloth cannot move forward. When adjusting, first pull up the machine head, loosen the screw of the lifting crank, and then gently lift the bracket with a screwdriver to make the feeding teeth face. Only 0.8-1 mm of the needle board is exposed. It is the standard size of the tooth height, as long as it is adjusted to this position, the cloth can move normally. Finally tighten the screws. When screwing the screw, the machine head must also be pulled up.
③The clothes go back and forth
When sewing clothes, the clothes often move back and forth, that is, one step forward and one step backward. This is caused by the feeding teeth being too high. The teeth are exposed on the needle plate and the plane is too high. The teeth are always exposed outside the needle plate and move back and forth, causing the cloth to move back and forth. When adjusting, loosen the crank screw of the lifting teeth, press the teeth down lightly with a screwdriver to lower the feed teeth to the standard height, that is, the teeth are exposed to the size of the needle plate 0.8-1 mm, and then tighten the crank screws.
④The lining moves backward
In the sewing work, sometimes the clothing material does not move forward, but moves in the direction of the operator, that is, the clothing material moves backward. This failure is due to the wrong angle between the crank of the upper shaft and the cam eccentric screw. Therefore, the teeth can move forward rhythmically. It is completely dependent on the movement of the cloth feeding cam. Because the cam itself is eccentric. Therefore, the forks are moved back and forth, and the forks drive the cloth feed shaft and the frame to promote the back and forth movement of the teeth. It can be seen that the eccentric position of the cam is very important.
The standard angle between the crank of the upper shaft and the cam screw. As long as the angle between the cam screw and the crank of the upper shaft is adjusted to the position of 260-300, the cloth will not go back.
When adjusting, pull down the rear cover of the machine head to see the cloth feed cam, insert a screwdriver into the casing, loosen the screw of the cloth feed cam, and then set the screw to 260-300 with the crank of the upper shaft Position, and then tighten the cam screw.
