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KE-430HX/KE-430HS, BE-438HX/BE-438HS
13. TROUBLESHOOTING
176
. Upper thread pulling out
13-7
Items with a “*” in the “Page” column should only be handled by a qualified technician.
Cause Check
Remedy
Page
Upper thread
Upper thread tenson
Decrease upper thread tension to such a degree that it
does not influence stitch quality.
Instruction
manual
Upper thread trailing length is
short.
Enable memory switch No. 500 setting: thread nipper
device operation.
21
Upper thread trailing length is
short or uneven.
Turn the sub-tension nut to adjust the tension.
* When using the thread nipper device, adjust the
upper thread trailing length to 35 - 40 mm.
Instruction
manual
Tension at the beginning of
sewing
Change the value of memory switch No. 551 to change
the upper thread tension releasing stitch count at the
sewing start.
* Although the upper thread pulling out will decrease,
the upper thread mis-winding will increase if the
upper thread tension is releasing at the sewing start.
21
Thread take-up
spring
Thread take-up spring
tension
Heighten take-up spring tension.
134*
Hook
Needle bar height and needle
bar lift amount
Adjust the needle bar height.
Adjust the needle and hook timing.
135*
Shuttle race base rim
Hook edge
Around needle plate hole
Remove thread chips or dust.
*
Lower thread
Lower thread tension is low.
Heighten lower thread tension.
Instruction
manual
Bobbin thread clamp spring
Install the bobbin thread clamp spring.
–
Sewing start speed
Slow start
Change the slow start pattern.
52
Sewing speed for the 1st
stitch
Reduce the sewing speed for the 1st stitch.
(Approximately 600 - 1000 sti/min)
52
Skipped stitches
Skipped stitches at the
sewing start
Refer to “13-2. Skipped stitches”.
173
. If the upper thread trailing length is unstable
13-8
Items with a “*” in the “Page” column should only be handled by a qualified technician.
Cause Check
Remedy
Page
Thread take-up
spring
Thread take-up spring
tension
・
If the upper thread trailing length varies considerably,
increase the thread take-up spring tension.
・
If the upper thread trailing length is short, decrease
the thread take-up spring tension.
・
If the thread take-up spring operation is unstable,
increase the thread take-up tension, and also
increase the stroke.
134*
Содержание BE-438HS
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