SWF E-U1201 - Thread Break Before Trimming by Moving Blade; Too Short Upper Thread After Trimming

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Thread Break
Before Trimming
by Moving Blade
Too Short Upper
Thread After
Trimming
① Too short upper thread
■ Check the tension of the
main and auxiliary tension
adjusting device on the
thread tension adjusting
plate.
■ Scratch or damage to the
moving blade
② Too short lower thread
■ The lower thread is not
smoothly released.
■ Too weak or too elastic
lower thread
① Thread escape due to too
short upper thread after
trimming
② Remaining upper thread on
the surface after trimming
due to too long upper thread
■ Adjust the upper thread
tension
■ Remove the scratch
(whetstone or sandpaper) or
replace the moving blade
■ Adjust or replace the
bobbin pressure spring of
the bobbin case
■ Clean the foreign materials
in the thread guide of the
bobbin case and check the
scratch
■ Replace the lower thread
■ Check the tension of the
upper thread
■ Set the remaining thread
length after trimming to be
[long] or [medium] in the
settings of the operational
panel
■ Set the remaining thread
length after trimming to be
[short] or [medium] in the
settings of the operational
panel
■ In the case where the head's
upper thread holder Velcro
is too narrow: Clean up the
inside of the Velcro
■ If the lower thread is
too short after
trimming, the initial
stitch is not formulated.
■ The remaining thread
length is set at
[medium] as default.
Corrective Action and Check PointCause of TroubleType Remarks
Areas to check for scratch