The lining moves backwards

In the sewing work, it sometimes appears that the clothing material does not move forward, but instead moves in the direction of the operator, that is, the clothing material moves backward. This failure is caused by 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 teeth fork is moved back and forth, and the teeth fork drives the cloth feeding shaft and the teeth frame to promote the teeth to reciprocate back and forth. 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 crankshaft 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 feed cam, insert a screwdriver into the casing, loosen the feed cam screw, and then turn the screw to 260-300° with the crank of the upper shaft Position, and then tighten the cam screw.