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
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