5. TROUBLESHOOTING
114
5-15. Upper thread mis-trimming
Cause
Check
Remedy
Page
Installation position of
upper thread trimmer
assembly
Adjust the installation position of upper thread
trimmer assembly by moving the setting plate
assembly.
⋅
Upper thread trimmer longitudinal position
adjustment
⋅
Upper thread trimmer cutting depth adjustment
91, 92
Upper thread trimmer
assembly
Upper thread trimmer
assembly holding force
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.
-
Trimmer driving arm
Upper thread trimmer
cutting depth
Adjust the position of the trimmer driving arm roller.
92
5-16. Needle strikes upper thread trimmer
Cause
Check
Remedy
Page
Installation position of
upper thread trimmer
assembly
Adjust the installation position of upper thread
trimmer assembly by moving the setting plate
assembly.
⋅
Upper thread trimmer longitudinal position
adjustment
⋅
Upper thread trimmer cutting depth adjustment
91, 92
Upper thread trimmer
assembly
upper thread trimmer
operating force
Remove any scratches and burrs, and adjust the
upper thread trimmer M to open when the projection
is pressed with a force of 4N or less.
-
4006Q
4005Q
Cotton yarn #60
Holding force approx. 2N
4005Q
4010Q