Upper Thread Run Out - Brother HE-800A Service Manual

5-13. Upper thread run out

Cause
Upper thread trimmer
assembly
Tension release
timing
Check
Installation position of
upper thread trimmer
assembly
Upper thread trimmer
assembly holding force
Opening cam position
End of tension release at
the beginning of sewing
Opening amount of
zigzag tension discs and
bar tack tension discs
Remedy
Adjust the installation position of upper thread
trimmer assembly by moving the setting plate
assembly.
⋅ Upper
thread trimmer
adjustment
⋅ Upper thread trimmer cutting depth adjustment
Adjust so that the thread does not come out when
you cut it with scissors and hold the end of the
thread between your fingers and gently swing the
assembly.
⋅ Bend the scissors U or replace them so that the
correct force is applied.
⋅ Repair any damage from striking the needle.
Adjust the position so that the scissors do not touch
the opening cam when the work clamp is lowered.
0.5 mm
Use parameter number 63 to retard the tension
release timing.
⋅ Adjust the zigzag tension discs by moving the
tension stud bracket in and out.
⋅ Adjust the bar tack tension discs opening amount
to 0.5 - 1.0 mm by removing the top cover and
moving the tension release cam.
Zigzag tension
HE-800A
5. TROUBLESHOOTING
longitudinal position
4005Q
Cotton yarn #60
Holding force approx. 2N
4006Q
4007Q
Tack tension
0.5 - 1 mm
4008Q
Page
91, 92
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94
Instruction
manual
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