JUKI MF-7900 Series Engineer's Manual page 87

Adjustment procedures
(5) Initial position of the lower thread trimmer mechanism
When the lower knife ❹ is located at its leftmost position, the
1.
top end of the lower knife ❹ has to be spaced 24 ± 0.5 mm
from the center of needle bar. Perform the adjustment by loos-
ening the nut  .
(6) Adjusting the stopper
Adjust the position of stopper  so that a clearance of 0.3 to 1
1.
mm is provided between looper  and clamp pressure adjust-
ing spring  when the counter knife is located at its leftmost
position (forward end).
(7) Adjusting the height of the lower knife
1. When the needle is positioned at its upper dead point, the
clearance of 0 to 0.1 mm has to be provided between the under
surface of lower knife ❹ and the top surface of looper  .
(Caution) Perform the work with the needle bar at the highest
position when actuating the thread trimmer mecha-
nism by hand.
(8) Adjusting the lower knife holder guide
When the lower knife ❹ moves from right to left, the lower knife
1.
guide holder  should lightly comes in contact with the guide
 .
Results of Improper adjustment
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