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
�
Inadequate height of
presser foot
(does not press the work
material)
Inspection & Repair
Remove dent or change the case
Adjust space
Oil the raceway of hook
Adjust timing
Adjust the lower dead stop
※
Check:
�
Thread path in presser foot
�
Around needle hole on
needle plate
�
Thread guide on the head
�
Thread path in tension
adjuster
Fix the material firmly
Adjust height
Set it at 0.5-0.7mm for
smooth feeding of upper
thread
Ref. 5-21, 5-12) 4)
Ref. 11-9, 11-9)
Ref. 11-6, 11-5)
Reference
Hook
Holder