JUKI LH-4128-7 Engineer's Manual page 15

2) Adjustment of the right and left feed dog positions, height, and
gradient
o Right and left feed dog positions
1. In order to make the right and left clearances be uniformly balanced
between the hole of the throat plate
feed base arm setscrew
direction. After adjustments, tighten the setscrew
2. If the above-mentioned adjustments are insufficient, loosen the set-
screw of the feed dog
bar until they become parallel to each other. Since then, tighten the
setscrew and adjust the horizontal positioning (adjustments of 1.
above) of the feed dog
(Caution) When the gauge is replaced, make right/left adjustments
of the feed dog
o Feed dog height
1. Minimize the feed amount by rotating the feed adjusting dial.
2. Turn the hand wheel so that the feed dog
maximum protrusion from the throat plate
3. Loosen the setscrew
adjust the feed dog
plate . After adjustments, tighten the setscrew
(Caution) 1. After adjustments, the needle location may be changed
in relation to the hole of the feed dog
o Feed dog gradient
1. Remove the cap
setscrew . Turn the roulette section
Standard adjustment
o LH-4128, LH-4128-7, LH-4168-7
Position where the engraved marking dot
coincides with the engraved marking dot
. (Engraved marking dot
o LH-4188-7
Engraved marker line horizontal
Adjustment Procedure
and the feed dog
to move the feed base arm
and adjust the feed dog
again.
.
and rotate the vertical feed link shaft
to 1 ± 0.1mm from the upper face of the throat
of the bed side face and loosen the feed bar shaft
to adjust the gradient.
B
is applicable to the LH-3500.)
A
, loosen the
in the axial
.
and the feed
is positioned to secure its
.
.
.
of the feed base arm
C
of the feed base arm shaft
– 11 –
Results of Improper Adjustment
When the feed dog is positioned too
high:
o The feed dog
contact with the throat plate
o The stitch length will be larger
than the value indicated by the
to
scale on the stitch dial.
o It can be a cause of thread
trimming deficiency.
When the feed dog is positioned too
low:
o The pitches of stitches become
smaller than the graduations of
the feed adjusting dial.
o The moving knife will come in
contact with the feed dog
the time of thread trimming.
This can be a cause of trimmer
malfunction.
will come in
.
at