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3-1-11. Checking the concentricity (How to handle the case where you have checked the
timing between the needle entry and the hook as described in 3-1-10 and have found
it is not correct)
1. Adjusting the concentricity between the hook driving shaft saddle and the needle bar
If the needle and the hole in the throat plate are not aligned, concentricity between them has to be ad-
justed. Correct the concentricity between the needle and the hole in the throat plate through the adjust-
ment of their positions in four directions (0°, 90°, 180° and 270°).
1) Remove two resin covers, eye protection cover
and presser foot.
Throat
plate
3) Reset the hook driving shaft saddle to the 0° position.
4) Attach the concentricity adjustment jigs to the throat plate and to the needle with the respective screws.
5) Adjust the T-shaped jig so that the needle bar jig passes through the hole in the T-shaped jig when low-
ering the needle bar.
Needle
Resin cover
Presser foot
Eye protection
cover
❹
❹
❸
❸
Hole in the
T-shaped jig
❸
❸
Needle
2) Remove the throat plate and the needle.
Insert needle bar jig
❹
into the needle bar.
When you lower the needle bar, carefully check whether it interferes with other parts.
