– 171 –
Trouble
Cause (1)
Cause (2)
Check and corrective measures
From the previous page
4-6) The thread take-up spring is
inappropriately adjusted.
6-A) The stroke of the thread take-
up spring is too long.
Shorten the stroke of the thread take-up spring.
6-B) The tension of the thread take-
up spring is too high.
Reduce the tension of the thread take-up
spring.
4-7) The material is inappropriate-
ly stretched.
7-A)
The presser is floating.
Adjust the clearance between the presser bar
holder and lifting plate.
7-B) The needle hole of the throat
plate is too large.
Use one with a smaller needle hole.
7-C) The thread relief on the back
side of the presser is too large.
Use one with a smaller relief or with no relief.
7-D) The parallel level of the presser
is inappropriate.
Replace the presser, or loosen the presser bar
holding screw and correct the foot bend.
5. Needle thread breakage
The needle thread splits finely or
breaks during sewing.
5-1) The thread path (including
the throat plate and foot) is
defective.
1-A) The thread path is not smooth.
Finish the thread path appropriately.
1-B)
The thread path has a flaw.
Finish the thread path appropriately.
1-C) The thread path has an obsta-
cle.
Check threading again and conduct correction
if necessary.
5-2) The tension of the needle
thread is inappropriate.
2-A) The tension of the needle
thread is too high or too low.
Adjust the tension of the needle thread to the
appropriate level.
2-B) The 1st thread tension is too
low.
Adjust the tension of the needle thread to elimi-
nate random movement of the thread between
the 1st and 2nd thread tension portions.
5-3) The thread take-up spring is
inappropriately adjusted.
3-A) The stroke of the thread take-up
spring is too long or too small.
Adjust the stroke of the thread take-up spring.
3-B) The tension of the thread take-
up spring is too high or too low.
Adjust the tension of the thread take-up spring.
3-C) The tension of the thread take-
up spring is too high or too low.
For the A-type thread tension, replace the cur-
rent thread take-up spring with a standard type
spring. (for a #60 or thicker thread)
To the next page
