JUKI MF-7900 Series Engineer's Manual page 51

Adjustment procedures
4. Longitudinal position of the feed dog (condition : feed momen-
tum 3.6 mm (maximum))
(1) Remove the bed top cover.
(2) Adjusting the longitudinal position of the main feed dog
Loosen setscrews ❷ in main feed lever ❶ when the feed dog
travels to the extreme front position (operator's side), adjust
the clearance from the edge of the slot of the throat plate to
the front face of the main feed dog to 0.6 ± 0.2 mm, and fix the
main feed dog with setscrews ❷ in the main feed lever ❶ .
(3) Adjusting the longitudinal position of the differential feed dog
Adjust the differential feed ratio to 1 : 1, and loosen setscrews
❹ in differential feed lever ❸ . Adjust the clearance provided
between the main feed dog and the differential feed dog to 1.6
± 0.2 mm and fix the differential feed dog with setscrews ❹ in
the differential feed lever ❸ .
(Caution) When the adjustment value changes greatly, feed dog
or throat plate will be broken.
Results of Improper adjustment
◦ When the fixing position of the
main feed lever slips greatly out
of position, abnormal noise or
abrasion will be caused.
◦ When the fixing position of
the differential feed lever slips
greatly out of position, abnormal
noise or abrasion will be caused.
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