(1) irregular movement of clothing

 

In the process of sewing clothes with sewing machine, there are some irregular phenomena such as uneven speed of clothes movement and the length of stitches. The movement of clothing depends on the cooperation of feeding teeth and pressing feet. Therefore, when the irregular movement of clothing occurs, it can be concluded that the failure of teeth and pressing feet or improper pressure regulation occurs. For example, foot pressure is too low. If the cloth is not pressed tightly, it will cause irregular movement. At this time, just screw down to tighten the clothing. If the foot press is too high to hold down the material, it will cause the material to move arbitrarily or not at all. When adjusting, first lift the foot press wrench, loosen the guide screw, then move the foot press rod from top to bottom, so that the distance between foot press and needle plate can be adjusted to 7-8 mm, then tighten the screw, and then drive.

 

Another reason is that the loosening of the tooth screw causes the teeth to shake left and right during operation, so that the clothing can not move forward regularly. The treatment is to remove the needle plate. Tighten the two teeth. Install the needle plate after tightening, check both sides of the teeth, if there is friction with the edge of the needle plate groove, it will cause noise and machine weight. At this time, only remove the needle plate, loosen the tooth screw, adjust the tooth position to the middle of the needle plate groove, tighten the tooth screw, then install the needle plate.

 

(2) Clothing material does not move forward

 

Clothing moves by teeth. When clothing doesn't move at all, it's only on the teeth. If the teeth are too low, clothing cannot move forward. When adjusting, first pull the nose, release the lifting crank screw, and then gently lift the rack with a screwdriver to make the feeding direction. Expose needle plate 0.8-1 mm. It is the standard size of the teeth. As long as it is adjusted to this position, the clothing can move normally. Finally tighten the screw. When twisting the screw, pull the nose up as well.

 

3. Clothing material going back and forth

 

When sewing clothes, clothes often move back and forth, that is to say, one step forward and one step backward. This is because the feeding teeth are too high, the surface of the exposed needle board is too high, and the teeth are always exposed outside the needle board to move back and forth, resulting in clothing moving back and forth. When adjusting, loosen the lifting crank screw, press down the teeth with a screwdriver, so as to reduce the feeding teeth to the standard height, that is, the size of the teeth exposed needle plate is 0.8-1 mm, and then tighten the crank screw.

 

(4) Clothing receding

 

Sometimes in the sewing work, the clothing does not move forward, but moves towards the operator, that is, the clothing goes backward. This fault is caused by the misalignment of the angle between the crank of the upper shaft and the eccentric screw of the cam. So the teeth can move forward rhythmically. It depends entirely on the pulling of the cloth feeding cam. Because the cam itself is eccentric. So the fork is moved forward and backward, and the fork drives the feeding axle and the bracket, which makes the teeth move forward and backward. Thus, the eccentric position of the cam is very important.

 

Standard angle between upper crank and cam screw. As long as the angle between the cam screw and the upper crankshaft is adjusted to 260-300, the clothing will not go backward.

 

When adjusting, pull the back cover of the nose down, you can see the feeding cam, insert the screwdriver into the inner part of the casing, loosen the feeding cam screw, then pull the screw to the position of 260-300 with the upper shaft crank, and tighten the cam screw.