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Reverse Feed Lever Position Adjustment
1. Set the stitch dial
to the maximum value on the scale.
2. Fasten the clamping screw
of the reverse feed connection arm.
3. Adjust so that the clearance of 0.5 to 1.5 mm is provided between the
reverse feed lever
and the stopper
when the reverse lever
is slightly pressed down. Then, fasten the clamping screw
.
(Caution)
For a sewing machine equipped with the touch-back
mechanism, a clearance of 11.5
±
0.5 mm should be
provided between the top end of the rod of the reverse
feed cylinder
and the reverse feed cylinder knuckle
joint
. (12
±
0.5mm for the LU-2220N-7)
Fasten the locknut
securely in the reverse feed cyl-
inder knuckle joint
.
Adjustment of condensation amount at thread trimming
(LU-2220N-7)
1. Loosen the fixing nut
of the reverse cylinder knuckle joint
.
2. Adjust the gap between the rod tip of the reverse cylinder
and the
reverse cylinder knuckle joint
. (Turn the rod tip of the reverse
cylinder
.)
o Reduce it by 12mm or more.
→
The amount of condensation is
reduced.
o Increase it by 12mm or more.
→
The amount of condensation is
increased.
3. After adjustments, tighten the fixing nut
.
4. After the adjustment of the amount of condensation, check the position
of the reverse feed lever.
(Caution) When the amount of condensation is reduced, the
residual thread length on cloth side becomes shorter.
However, if this amount is too small, the material cloth
may be torn according to the stitch length. Such an
inadequate setting can result in stitch skipping or thread
breakage.
On the other hand, too much condensation can give
rise to defective thread spreading, finally leading to
thread breakage.
The recommendable amount of condensation is 1.5 to
2.0mm.
If the clearance between the stopper
and the reverse feed lever is too
large:
o The top end of the reverse feed
lever
will interfere with the bed.
As a result, the stitch length for the
reverse feed stitching may be
shortened.
If the clearance between the stopper
and the reverse feed lever is too
small:
o The reverse feed lever
will in-
terfere with the stopper
. As a
result, stitch length for the normal
feed stitching may be shortened.
Adjustment Procedure
Results of Improper Adjustment