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6. The needle thread is untrimmed. 6-1) Stitch skipping at the final stitch 1-A) The needle is inappropriately Mount a needle appropriately and make sure that the
(But the bobbin thread is trimmed.) occurs. mounted. needle is not bent.
1-B) The stroke of the thread take- Shorten the stroke of the thread take-up spring.
up spring is too long.
1-C) The hook is inappropriately Check whether no stitch skipping occurs at low sewing
adjusted. speed and adjust the hook appropriately.
(Hasten the timing of the hook.)
6-2) The blade portion of the knife is 2-A) The blade portions of the moving Remove the throat plate and move the knife by hand to
blunt. and counter knives are not per- cut 3 pieces of cotton thread #50.
fectly aligned at thread trimming. If all of the 3 cotton threads are uniformly cut, there is no
(The mounting angle, position, problem.
and blade inclination of the If they are not uniformly cut, sharpen the blade portion of the
counter knife are not matched counter knife, readjust the blade inclination, and readjust the
with those of the moving knife.) mounting position of the counter knife.
7. The bobbin thread is untrimmed. 7-1) The backward movement of the 1-A) The backward movement of the Measure the backward movement length of the moving knife.
(But the needle thread is trimmed.) moving knife is insufficient. moving knife is inappropriately Adjust the position of the thread trimming cam in the right-
adjusted. (The position of the left direction to set the backward movement length of the
knife operation axis or the thread knife to within 2.5 to 3 mm (3 to 3.5 mm for SH) if the
trimming cam in the right-left measurement result is out of the range.
direction is inappropriately
adjusted.)
7-2) The position of the bobbin thread 2-A) A hook other than the specified Check whether the current hook has a guide slit for the bobbin
at thread trimming is unstable. hook is used. thread. If the hook has no such a slit, replace the hook with a
hook for threat trimming.
8. The wiper interferes with the needle. 8-1) The height of the position where Mount the wiper appropriately.
the wiper is mounted is
inappropriate.
Trouble Case (1) Case (2) Check and Corrective measures
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