19
(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
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.
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 ats). 
  * 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