−
85
−
Trouble
Cause (1)
Cause (2)
Checking order and adjusting procedure
Page
3. Needle thread slip-off
From the previous page
2-7)
Change of needle thread loop
3-1)
Installation or timing of needle
thread trimmer is improper.
3-2)
Finish of thread presser spring
is improper.
3-3)
Setting of tension at the start of
sewing is improper.
7)-A
Loop of spun thread or cotton
thread falls at the speed of
3,300 rpm or more.
7)-B
Loop is hard to be made with
fabric related to knit.
1)-A
Opening timing of trimmer is too
early.
1)-B
Thread grasping force of the
trimmer is too weak.
1)-C
Closing amount of the trimmer
is too small.
2)-A
Thread presser spring cuts
needle thread.
3)-A
Tension is too high.
Decrease the number of revolution.
Raise the lowest point of needle bar by 0.6 mm, and re-adjust needle-
to-hook timing.
It is effective to slightly lower needle bar than the case of standard
timing and to delay the hook timing.
Adjust the longitudinal position of needle thread trimmer driving cam
so that the trimmer gradually opens at the position of approximately 2
to 3 mm from the start of sewing.
Correct the thread presser spring so that the spring comes in contact
with the whole of the blade of thread trimmer.
When there is a mismatch of the trimmer, replace it.
Retreat the needle thread trimmer driving cam.
Finish with buff the contact face of the thread presser spring with needle
thread.
Adjust the tension so that whip stitching is performed at the start of
sewing. Memory switch No. 6
(See page 63.)
To the next page
Adjust so that the blade point of hook comes to
the position of approximately 1 mm from the top
end of the needle eyelet.
1 mm
Summary of Contents for LBH-1700
Page 1: ...R ENGINEER S MANUAL 29339504 No 04 Electronic Buttonholing Machine LBH 1700 Series ...
Page 55: ... 51 MEMO ...
Page 124: ... 120 ...
