Adjustment Of Feed Dog Height And Longitudinal Movement (Mechanism Without Differential Feed) - JUKI MS-3580 Serie Manual De Instrucciones

9. Adjustment of feed dog height and longitudinal movement
(mechanism without differential feed)
WARNING :
Perform the work after turning OFF the power to prevent accidents caused by the abrupt start of the
sewing machine.
(1) Height of main feed dog
The standard height is defi ned when the main feed dog 1 attains the highest level and the rear root section of the main
feed dog 1 coincides with the upper face of the throat plate 2 of the main feed dog 1 .
(2) Adjustment of longitudinal movement of main feed dog
The maximum amount of feed of the main feed dog 1 is 3.6 mm. (Standard : 3.2 mm)
When the main feed dog 1 attains its maximum feeding amount, the standard positioning is secured when Clearance
"A" and Clearance "B" are equalized. Clearance "A" is defi ned as the distance from the feed groove front section of
the throat plate 2 to the front section of the main feed dog 1 in position where the main feed dog 1 stays in the most
advanced position. Clearance "B" is defi ned as the distance from the feed groove rear section of the throat plate 2 to the
rear section of the main feed dog 1 in position where the main feed dog 1 has attained the most retreated position. (A = B)
Height of main feed dog
Coincidence
Clearance of the main feed dog
in the most advanced position
2
2
A
B
Clearance of the main feed dog
in the most retreated position
5
1
6
4
1
2
1
1
6
− 35 −
(3) Adjustment of the vertical height of main feed dog
Apply the rear support screw 3 to the bottom right of
1)
the main feed dog 1 , tighten the setscrew 4 , and
mount the throat plate 2 .
Check the standard height of the main feed dog 1 .
2)
™ If the main feed dog 1 is low, raise the rear
support screw 3 .
™ If the main feed dog 1 is high, raise the rear
support screw 3 .
Remove the throat plate 2 , loosen the setscrew 4
3)
to remove the main feed dog 1 , and adjust height of
the front support screw 5 .
After adjustments, mount the main feed dog 1 ,
4)
tighten the setscrew 4 , mount the throat plate 2 ,
and tighten the setscrew 6 .
When the height of main feed dog 1 is
insuffi cient
™ The amount of feed is decreased and
uneven feeding can occur.
™ When the height of the rear needle guide
is lowered, this will cause breakage of a
needle or stitch skipping.
When the height of main feed dog 1 is
excessive
™ This can be a cause of the materials
pushed back to the front side, or of
giving rise to feed fl aws.
™ When the height of the rear needle
holder is raised and the margin of the
needle contact position is increased,
this will cause failure in producing loops
and stitch skipping.
1
4
3