In sewing work, sometimes the fabric does not move forward, but instead moves in the direction of th

In sewing work, sometimes the fabric does not move forward, but instead moves in the direction of the operator, that is, the fabric moves backwards. The occurrence of this fault is due to the incorrect angle between the upper shaft crank and the cam eccentric screw. Teeth can move forward rhythmically, entirely through the movement of the feeding cam. Because the cam itself is eccentric. So make the fork move back and forth, and the fork drives the feeding shaft and tooth rack, promoting the reciprocating movement of teeth. It can be seen that the eccentric position of the cam is very important.
The standard angle between 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 a position of 260-300, the fabric will not fall back.
When adjusting, pull the back cover of the machine head downwards to see the feeding cam. Insert a screwdriver into the machine casing, loosen the screw of the feeding cam, then turn the screw to a position that is 260-300 degrees from the upper shaft curve, and then tighten the cam screw.