With the long, high-speed working, the needle point will become blunt, even bent. The distance between the needle point and hook becomes large, the hook point can't hook the thread, and then the machine will have a skipped stitch.
Turn the hand wheel, make sure the needle position is in 2.2-2.5mm (from the bottom to up), and adjust the needle position within 1-1.1mm(above the needle hole). Then adjust the distance by 0.05-0.1mm between the needle and hook.
Loosen the presser foot nut, adjust the pressure to fit the presser foot, clockwise is heavy, anticlockwise is light, the right position is 29-32mm.
