JUKI MF-7700 Series Engineer's Manual page 43

Standard Adjustment
1. When making the stitch length more than 3.6 mm, loosen setscrew
2 of the feed adjustment stopper pin, turn feed adjust knob 1
clockwise, and adjust the stitch length. By turning feed adjust knob
1, pin 3 is pushed out. Fix pin 3 with setscrew 2 in the feed
adjustment stopper pin after adjudting the stitch length.
Maximum stitch length is 4.4 mm.
2. Loosen lock nut 4 and raise release lever 5 to increase the
differential feed ratio, and lower it to decrease the differential feed
ration.
Fine adjustment of the differential feed ratio can be performed with
micro-adjust knob 6.
When engraved marker 7 of the differential feed lever is aligned
with the long engraved marker line on the dial plate, the momentum
of the main feed dog and the differential feed dog becomes almost
1 : 1.
Results of lmproper Adjustment
™ When the stitch length is set to more
than 3.6 mm, the contact of main feed
dog, differential feed dog and throat
plate occurs due to the adjustment in
case of the standard position of the
feed dog. Additionally machine the
feed dog to satisfy the need.
™ When using the machine with the
stitch length of more than 2.5 mm and
the maximum differential feed ratio,
turn the machine by hand and check
whether there is any contact with feed
dog and throat plate.
In addition, when more gathering is
necessary, grind the differential feed
dog.
40
– –