12
TO ADJUST THE TIMING OF THE NEEDLE
AND THE UPPER KNIFE
Correct Setting:
The upper knife timing is the same as that of the needle bar. In fact, when the needle bar is at highest
position, the upper knife should be also at its highest position.
To adjust:
1. Remove the back cover unit.
2. Loosen two setscrews A, and move the balance weight to left.
3. Loosen two setscrews B, and adjust the needle and upper knife timing.
# Turn the upper knife drive cam to the direction C when the upper knife timing is being delay.
# Turn the upper knife drive cam to the direction D when the upper knife timing is too soon.
4. Tighten two setscrews B firmly. Move the balance weight to right.
Match the guide line on the balance weight with the one of the main shaft correctly.
Then tighten the two screws A.
5. Turn the handwheel toward you one cycle, and recheck the needle and the upper knife timing.
6. Attach the back cover unit.
When the needle bar goes up,
the upper knife goes up.
When the needle bar goes down,
the upper knife also goes down.
Direction C
Setscrew B
Setscrew A
Direction D
Guide line on main shaft
Upper knife drive cam