JUKI MF-7900 Series Engineer's Manual page 117

Adjustment procedures
3. Adjustment procedure of engagement amount of knives
(1) Loosen setscrew ❸ in the upper knife holder and adjust so that
the engagement amount of the top end of the upper knife ❶
and lower knife ❷ is approximately 0.5 mm when upper knife
❶ is in its lowest position.
(2) After the adjustment, perform "7.-(2)-1. Adjusting the upper
knife pressure".
4. Replacement procedure of upper knife and lower knife
(1) Loosen setscrew ❹ in the joint asm., and remove waste cloth
pipe ❺ .
(2) Loosen setscrew  and keep in that state. Loosen lower knife
keep plate setscrew ❻ . Draw out lower knife ❽ in the direction
of the arrow with knife shaft ❼ pressed in the direction of the
arrow.
(3) Insert a new lower knife ❽ in the groove of lower knife holder ❾ ,
and tighten setscrew ❻ in the lower knife presser plate in the
state that the blade point is aligned with the top surface of the
throat plate.
(4) When replacing the upper knife  , loosen setscrew  in the
upper knife holder, remove upper knife holder  , loosen set-
screw  in the upper knife, and remove upper knife  .
(5) Fix new upper knife  with setscrew  in the upper knife.
(6) After replacing the upper knife  , align the left end face of up-
per knife holder  and the left end face of knife shaft ❼ , and
tighten setscrew  in the upper knife holder.
(7) After replacing the upper knife  , perform "7.-(2)-1. Adjusting
the upper knife pressure" and "7.-(2)-3. Adjustment procedure
of engagement amount of knives".
Results of Improper adjustment
– 103 –