12-6
Error Type
Cause
⑫
Dent on thread path on
hook and bobbin case
⑬
Narrow space between
hook holder and groove for
hook holder (on hook)
⑭
Insufficient oil in hook
⑮
Poor timing of needle and
hook
�
Incorrect lower dead stop
�
Dent on thread path
�
Fabric moves on the frame
(fabric not fixed on the
frame)
�
Inadequate height of
presser foot
(does not press the work
material)
Remove dent or change the
case
Adjust space
Oil the raceway of hook
Adjust timing
Adjust the lower dead stop
※
Check:
①
Thread path in presser foot
②
Around needle hole on
needle plate
③
Thread guide on the head
④
Thread path in tension
adjuster
Fix the material firmly
Adjust height
Inspection & Repair
Check rotary hook
※
Set the space at 0.5-
0.7mm for smooth
feeding of upper thread
See 5-13-4 (p.5-20)
See 11-8 (p.11-9)
See 11-4-3 (p.11-6)
Reference
Hook
holder
0.5~0.7