Maintenance; Adjusting The Needle-To-Hook Relation - JUKI LBH-1790 Instruction Manual

^. MAINTENANCE

1. Adjusting the needle-to-hook relation
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the fol-
lowing work after turning the power off and ascertaining that the motor is at rest.
1
0.05 mm
1
3
A
B
C
2
– 47 –
Adjust the needle-to-hook relaton when the needle
enters the center of the needle hole n the throat plate.
(1) Needle bar height
) Brng down the needle bar to the lowest pont.
2) Insert the part [] A of tmng gauge nto the gap be-
tween the bottom end of needle bar and throat plate,
where the bottom end of the needle bar touches the
top of the part [] A of the tmng gauge.
3) Loosen needle bar connecton screw 1 , and
adjust the heght of the needle bar.
(2) Set the needle to hook relation in the
following way :
) Rotate the hand pulley n the correct drecton untl
the needle starts to go up from ts lowest pont.
2) Insert the part [2] B of the tmng gauge nto the
gap between the bottom end of the needle bar
and the throat plate, where the bottom end of the
needle bar touches the top of the part [2] B of
the tmng gauge.
3) Loosen setscrew C of the hook sleeve, and algn
blade pont of the sewng hook wth the center of
needle hole. Make adjustment so that a clear-
ance of approx. 0.05 mm s provded between
the needle and the blade pont of the hook.
(3) Adjusting the bobbin case positioning stopper
Adjust wth setscrew 3 so that the contact of the top
end of bobbn case postonng stopper 1 and the
end of nner hook 2 s 0 to 0.2 mm.