JUKI MF-7700D Series Engineer's Manual page 103

Adjustment Procedure
[Adjusting procedure]
1. Adjusting DOWN position
(1) Turn the handwheel to adjust the down position of the needle
to the position where top end
loop of the left needle thread.
A
(2) Loosen and remove screw
(3) Loosen by 1/2 turn screw
synchronizer with a screwdriver to make the detecting plate
lightly turn by hand.
(4) Turn detecting plate
on the near side of sewing machine handwheel in the direction
of rotation of the sewing machine (clockwise direction), find a
position where LED
plate so that it is near the center of the lighting range of
LED. After the adjustment, temporarily tighten lightly screw
at the top end of the shaft.
2. Adjusting UP position
(5) Adjust mark
turned 10 mm from the center of mark
side in the direction of rotation.
(6) Loosen screw
temporarily tightened. Turn clockwise detecting plate
adjusting UP position) located on this side, find a position where
LED of U lights up, and adjust the detecting plate
it is near the center of the lighting range of LED.
(Caution) At this time, securely press the handwheel by hand
so that the detecting plate
position which has been adjusted in steps (1) to (4)
does not move.
(7) Through the aforementioned steps, the adjustment of UP
position and DOWN position is completed. Securely tighten the
screw at the top of the shaft.
(8) After the adjustment, install the cover by means of screw
the synchronizer cover.
(Caution) When using the synchronizer as UP/DOWN stop
position type without using the thread trimmer
device, change the setting of the function setting No.
74 to "1 (thread trimming) → → → → → 0 (UP/DOWN position)".
(Setting procedure of both SC-500 and SC-510 is
common.) Thread trimmer safety device error occurs
unless the setting is changed, and it is impossible
to operate the sewing machine. So, be careful.
of the looper has scooped
B
in the cover of synchronizer.
at the top end of the shaft of
(for adjusting DOWN position) located
of D lights up, and adjust the detecting
on the handwheel to the position where it is
at the top of the shaft which has been
on the machine head
(for
so that
located on DOWN
of
– 99 –
Results of Improper Adjustment
UT31