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WARNING :
Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine.
Trouble
Cause (1)
Cause (2)
Checking order and adjusting procedure
17. The looper thread bulges out
17-1) Knife width
1-A)
The knife width is too small for the over-
edging width.
Use a knife having width suited to the overedging
width.
17-2) Adjustment of the
looper thread take-up
2-A)
The looper thread take-up draws out
excessive looper thread.
Decrease the radius of the looper thread take-up
(left). Raise the looper thread take-up (right).
18. Looper thread bite
18-1) Knife width
1-A)
The knife width is too large for the over-
edging width.
Use a knife having width suited to the overedging
width.
18-2) Adjustment of the
looper thread take-up
2-A)
The looper thread take-up draws out
insufficient amount of looper thread.
Increase the radius of the looper thread take-up
(left). Lower the looper thread take-up (right).
19. Knotting position is not correct.
Right side
Knots are
deflected to
the upper
looper side.
19-1) Threading
1-A)
Re-threading after thread breakage,etc.
has been done erroneously.
Refer to the threading diagram.
19-2) Adjustment of the
looper thread take-up
2-A)
The height of the looper thread take-up
(left) is not correct.
Raise the looper thread take-up (left) to increase
the amount of upper looper thread, and the knot-
ting position moves toward the lower looper side.
2-B)
The upper looper thread guide (right) is
too short.
Lengthen the upper looper thread guide (right).
20. Uneven material feed
20-1) Presser foot pres-
sure
1-A)
The presser foot pressure is too high.
Reduce the presser foot pressure except for the
uneven material feed due to packering.
20-2) Presser foot
2-A)
The hinge is too stiff.
Remove the stiffness provided no hinge play is
produced.
2-B)
Scratches on or defective finish on the
presser foot sole produce friction be-
tween the presser foot and materials.
Buff the presser foot sole for good surface finish.
20-3) Tilt of feed dogs
3-A)
The front is too high.
Make the front down. However, be sure to align
the differential feed dog with the main feed dog.
20-4) Height of feed dogs
4-A)
A different in level exists between the
main feed dog and differential feed dog.
Eliminate the difference in level.
20-5) Adjustment of differ-
ential feed
5-A)
The differential feed has been improp-
erly adjusted.
Provide differential feed suited to the material.
