25
Mechanical Adjustment
Backlash between hook drive gear and lower shaft gear
The rotary play of the hook should be 0.8 mm or less when the tip of rotary hook is within the width of feed dog.
A
(A)
(B)
Lower shaft bushing
(front)
Hexagonal
socket screw C
Hook driving gear
Lower shaft gear
Lower shaft bushing (rear)
Hexagonal socket
screw D
Tip of rotary hook
1. Remove the base cover and bed cover (see page 3).
2. Remove the presser foot, the needle plate and the
bobbin holder.
* Cover the needle plate with the fabric to prevent
damaging when removing, the needle plate.
3. Turn the handwheel toward you so the tip of the
rotary hook is within the width of feed dog as shown.
Check the rotary play of the hook.
4. If the backlash is too much or too little, loosen the
hexagonal socket screws C and D
(use an Allen wrench
of 2 mm width across flats)
.
* Turn the both lower shaft bushings in the direction A,
if the backlash is more than 0.8 mm.
* Turn the both lower shaft bushings in the direction B,
if the engagement of gear is too tight, and the machine
does
not turn smoothly.
NOTE:
The notches in the both bushings should face in the same
direction.
5. Tighten the hexagonal socket screws C and D.
6. Attach the base cover, bed cover, the presser foot,
needle plate and the bobbin holder.
Width of feed dog
Notch
0.8 mm or less
Notch
B
Notch