JUKI MF-7800D Series, Engineer'S Manual

Page: 91 / 165

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(1) Loosen screw and remove cover .
(2) Turn disk on this side by hand, and adjust the adjusting mark “B”
of disk in the rear to edge
A
of disk .
(3) Temporarily tighten the synchronizer to the lower main shaft
handwheel with screw .
(4) When the power is turned ON, the sewing machine turns
approximately by one half and stops.
(5) Turn OFF the power, and loosen screw .
(6) Holding
B
section of the synchronizer so as not to move, turn the
upper main shaft handwheel, adjust mark of the handwheel to
the position where mark on the machine head side aligns with it,
and temporarily tighten screw .
(7) Again, turn ON the power, and confirm that the sewing machine
stops at the position where mark of the handwheel aligns with
mark on the machine head side. Then tighten screw .
(8) After the adjustment, be sure to attach cover and tighten screw
.
(9) When the sewing machine stops in the DOWN position after the
adjustment above has been performed, the top end
C
of the looper
comes to be located in the position where it has scooped the loop
D
of the left needle thread.
(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).” (The setting
method is common to both SC-500 and SC-510.) You
have to note that a thread trimmer safety device error
will occur and the sewing machine will fail to operate if
the setting is left unchanged.
Adjustment Procedure Results of Improper Adjustment
UT25