JUKI MO-6000S series Engineer's Manual page 59

Adjustment Procedures
™Standard of the position where timing is advanced by 19˚from
the upper dead point of the needle
1) Timing is advanced by approximately 21˚ from the upper dead
point of the needle at the position where the hole in the periphery
of the handwheen faces just under.
1) Remove top cover, locus cut base, exhaust slot support, and
adjusting arm spring.
2) Loosen top presser adjusting screw 1, top presser adjusting
screw nut 8, release top presser pressure, and check the play
in the lateral direction of top feed dog 2.
3) Remove the needle thread tank, loosen setscrew 3 in the feed
bar guide B and temporarily tighten feed bar guide B 4 so that
top feed bar 6 is put between feed bar guides B 4 and A 5.
4) Move top feed dog 2 up or down and adjust so that top feed
dog 2 comes down by its weight and that the play in the lateral
direction of top feed dog 2 is kept down to a minimum.
5) When jar is produced at top feed dog 2 and the top feed dog
does not come down by its weight even after adjusting feed
bar guide B 4, loosen setscrew 7 in the feed bar guide A and
adjust feed bar guide A 5 at the same time. At this time, adjust
the lateral position of top feed bar 6 to the position where top
feed dog 2 drops naturally when moving it up or down several
times.
6) Securely tighten the respective setscrews and check that there
is neither play nor jar.
7) Return adjusting arm spring, exhaust slot support, locus cut
base and top cover to their home places.
Refer to "(27) Vertical stroke of the top feed dog".
(Caution) When jar occurs between feed bar guide A 5 and B 4,
and top feed bar 6, jumping of top feed dog 2 will be caused.
Adjust the top feed dog to such an extent that it comes
down by its weight as mentioned above.
Results of Improper Adjustment
™ When the play in the lateral
direction of top feed dog 2
occurs, the top feed dog comes
in contact with the presser and
noise occurs or feed dog defect
is apt to be put on cloth.
™ On the contrary, when torque
occurs between fedd bar guides
A 5 and B 4, and top feed bar
6, inducement of the jumping
phenomenon of top feed dog 2
will be caused.
55