Trouble
Case (1)
Case (2)
Check and Corrective measures
Page
From the previous page
Needle guards
A needle guard has been improperly
Refer to the pertinent Standard Adjustment.
18
positioned, causing the needle point to
strike it.
Needle No.
The needle is too thin for the materials.
Replace the needle with a thicker one.
Thread tension
The thread tension is too high.
Reduce the thread tension.
Height of the feed dog or needle
The feed dog is too high, or the needle is
Refer to the related Standard Adjustment.
4, 20
too low, causing the needle to deflect with
resultant needle breakage.
4. The needle point is crushed.
Needle guard
The needle guard C is too low, or its
Increase the height of the needle guard (C).
18
(Double chain stitch needle)
longitudinal position is not correct.
Check the clearance between the needle and
needle guard.
Contact with the looper
The tilt of the looper is not correct. The
Check the tilt of the looper. Correct the longitudinal
16
longitudinal motion of the looper is not
motion of the looper, and increase the clearance
correct.
between the looper and needle when the
looper reaches its most retracted position.
▼
5. Overlocking needle thread stitches
Lower looper
The blade point has defective shape and
Replace the lower looper.
are skipped.
does not catch needle thread loops.
Adjustment of the loopers.
The clearance or the amount of return is
Refer to the relevant Standard Adjustment.
8
not correct.
Needle thread presser
The duration in which the presser holds the
Refer to the pertinent Standard Adjustment.
needle thread is not correct, and unstable
loop result.
Needle
The needle is bent or improperly oriented.
Replace the bent needle. Correctly orient and
A needle or DC x 1 is used.
attach the needle.
Use a DC x J27 needle for a stretchy thread.
Needle guards
Incorrect height or clearance prohibits
Refer to the pertinent Standard Adjustment.
18
correct guide for the needle. If a needle
guard is too high, loops are crushed with
consequent stitch skipping.
The lower looper fails to catch
needle thread loops.
Right side Wrong side
– 50 –
to the next page
Содержание MO-6700D Series
Страница 49: ...45 2 Upper looper components...