Jack W4 Series - Upper cutter group adjustment; Upper knife meshing amount adjustment

confirm the needle bar at the highest point, the lower looper at the far right
point, and then can only manually push the lower cutter assembly to
confirm the relevant position.
二、上切刀组调整（adjust the cutter group）
注意：安装调整上切刀组前，必须先确认针杆处于最高点，且喂针与机针位置处于
标准状态。Note: Before installing and adjusting the cutter group, you must
first confirm that the needle bar is at the highest point and the position of
the needle and the needle are in the standard state.
1、上切刀组动刀与定刀啮合量的调整
请把定刀与动刀的啮合量调整为0.5-1.0mm，可通过松开紧定螺钉，上下移动动刀
架，调整定刀与动刀的啮合量为0.5-1.0mm（图13）。
1、 on the knife group knife and fixed knife meshing amount of adjustment
Adjust the amount of engagement between the fixed knife and movable
knife to 0.5-1.0mm. By loosening the set screw, move the movable knife
holder up and down to adjust the amount of engagement between the
fixed knife and movable knife to 0.5-1.0mm (Figure 13).