Adjusting The Needle Guard - JUKI MF-7900 Series Engineer's Manual

(12) Adjusting the needle guard

WARNING :
Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the
sewing machine.
1. Standard position of the rear needle guard
(1) Lateral position of rear needle guard
It is the standard that the lateral position of rear
needle guard ❶ is the position where the rear needle
guard ❶ receives the needle in the range of B.
(2) Position of the height of the rear needle guard
It is the standard that the clearance provided between
crest line A of rear needle guard ❶ and the top end of
right needle is 1.5 to 2 mm when top end of the looper
❹ comes from the extreme right position to the center
of right needle.
(3) Pressing amount of the rear needle guard
It is the standard that when top end of the looper ❹
comes from the extreme right position to the center of
right needle, the clearance provided between the right
needle and top end of the looper ❹ is 0 to 0.05 mm,
when top end of the looper ❹ comes to the center of
middle needle, the clearance provided between the
middle needle and top end of the looper ❹ is 0 to 0.05
mm, and the pressing amount of the top end of needle
touches the rear needle guard ❶ .
(4) Loosen two setscrews ❽ in the rear needle guard
cam and perform the adjustment of the rear needle
guard ❶ .
It is the standard position where setscrew ❽ in the
rear needle guard cam (screw No. 1 in the direction
of rotation) aligns with engraved marker dot  on the
looper driving shaft.
Standard adjustment
– 28 –
❹
A
❶
❶
❺
B
❹
❶
❶
Advanced
Retarded
1.5 to 2 mm