Position Of The Hook Rotation Stopper Plate; Adjusting The Bobbin Thread Tension - JUKI HZL-X Series Service Manual

6-8 Position of the hook rotation stopper plate

○ Remove the throat plate.
Adjustment procedure
1. When the bobbin case holder is placed inside the rotating hook, loosen the setscrew and determine the
longitudinal position of the rotation stopper plate so that the projection of the bobbin case holder and the
leaf spring of the rotation stopper plate are located as illustrated in the enlarged partial view. To adjust the
lateral position of the rotation stopper plate, press the plate in the right direction by the amount of play and
secure with the setscrew.
* The hook race surface and the bobbin case holder may be stained with dirt, oil or grease. Wipe them off
with an alcohol-soaked cloth where necessary.
If those parts are left stained, chattering or thread slip-off noise of the bobbin case holder can occur.

6-9 Adjusting the bobbin thread tension

○ Remove the throat plate.
Adjustment procedure
1. Position the bobbin case holder and a tension gauge as illustrated in the sketch below. Using SHAPPE
Span thread #60, adjust the bobbin thread tension to 0.13 ± 0.02 N with the adjusting screw.
At this time, carefully prevent the bobbin thread from coming in contact with the throat plate or other relat-
ed parts.
Adjust so that the projection and
Setscrew
leaf spring are aligned with this line.
Adjusting screw
– 18 –
Enlarged partial view
Adjusting screw