This is due to send the teeth caused by too high, the teeth exposed needle plate plane is too high, the teeth are always exposed outside the needle plate reciprocating movement, resulting in clothing to move back and forth.
Sewing clothing, often there will be clothing to move back and forth, that is, one step forward, but also to the phenomenon of a step back.
Adjust the teeth when the teeth to turn the teeth, the teeth with a screwdriver down the pressure, so that the feed teeth reduced to the standard height, that tooth exposed needle plate 0.8-1 mm size, and then tighten the crank screw.
