Common problems with sewing machines

1 clothing is moving irregularly

In the process of sewing a sewing material using a sewing machine, there are sometimes irregularities in the speed of movement of the cloth, and the irregularity of the length of the stitching. The cloth material moves forward by the cooperation of the feed dog and the presser foot. Therefore, when the above-mentioned irregular movement of the cloth material occurs, it can be concluded that the tooth and the presser foot are malfunctioning or the pressure is improperly adjusted. For example, the presser foot pressure is too small. If the pressure is not tight, it will cause irregular movement. At this time, just turn the adjusting screw downward to press the cloth. The presser foot is too high to press the fabric, and it will cause the fabric to move freely or not move at all. When adjusting, first lift the presser wrench, loosen the guide screw, and then press the presser foot from top to bottom. After the distance between the presser foot and the needle plate is adjusted to a height of 7-8 mm, the screw is tightened and then used.

Another reason is that the teeth are loosened and the teeth are shaken left and right during operation, so that the cloth cannot be moved forward regularly. The treatment is to remove the needle plate. Tighten the two teeth screws. After tightening, install the needle plate and check whether the edges of the teeth are rubbed against the edge of the needle plate groove. If there is friction, it will cause noise and weight. At this time, only remove the needle plate and loosen the tooth screw. Adjust the position of the tooth to the middle of the needle plate slot, tighten the tooth screw, and then install the needle plate.

2 clothing does not go forward

The movement of the cloth is transmitted by the teeth. When the clothing does not move at all, only find fault on the teeth. If the tooth position is too low, the fabric cannot move forward. When adjusting, first raise the nose, loosen the lifting crank screw, and then gently lift the bracket with a screwdriver to make the feeding direction. The needle plate is exposed to 0.8-1 mm. It is the standard size of the teeth. As long as it is adjusted to this position, the fabric can move normally. Finally tighten the screws. When screwing the screw, also pull the nose.

3 clothes go back and forth

When sewing fabrics, there are often cases where the fabric moves back and forth, that is, one step forward and one step backward. This is caused by the too high feed dog teeth. The plane of the teeth exposing the needle plate is too high, and the teeth are always exposed to the outside of the needle plate to reciprocate, causing the cloth to move back and forth. When adjusting, loosen the lifting crank screw and gently press the tooth down with a screwdriver to lower the feeding tooth to the standard height, that is, the tooth is exposed to the 0.8-1 mm size of the needle plate, and then tighten the crank screw.

4 clothing back

In the sewing work, sometimes the cloth does not move forward, but instead moves toward the operator, that is, the cloth material is retracted. This failure is caused by the misalignment of the upper shaft crank and the cam eccentric screw. The teeth can move forward in a rhythmically. It is entirely driven by the feed cam. Because the cam itself is eccentric. Therefore, the fork is moved forward and backward, and the fork further drives the feeding shaft and the dental frame to promote the reciprocating motion of the teeth. It can be seen that the eccentric position of the cam is very important.

The standard angle of the upper shaft crank and the cam screw. As long as the angle between the cam screw and the upper shaft crank is adjusted to 260-300, the cloth will not be retracted.

When adjusting, pull the back cover of the machine head down, you can see the feeding cam, insert the screwdriver into the inside of the casing, loosen the feeding cam screw, and then turn the screw to the upper shaft and turn it into 260-300. Position and tighten the cam screw.