−
70
−
Troubles
Cause (1)
Cause (2)
Corrective measures
From the previous page
3.
Needle breakage
4.
Worn out needle point
Thread
Looper avoid
Needle heat
Needle entry
Spreader
Interference of looper with scooping
movement of needle
Needle guard
Needle thickness No.
Thread tension
Feed height, Needle height
Needle guard
Interference with looper
Poor quality and weakness of thread
Too strong contact of looper back with
needle resulting in thread breakage
In case needle heat is generated looper
thread’s contact with needle causes thread
breakage, specially at the time machine
is at rest.
Needle hits the throat plate or presser foot
because the needle entry is not correctly
positioned for the plate or foot.
Too little clearance between spreader and
needle
Needle hits looper resulting in needle
breakage.
Too strong contact against needle guard
or needle point hits needle guard due to
incorrect position.
Too thin needle for fabric used
Needle thread tension is too strong.
Feed dog is too high or needle height is
too low resulting in needle breakage due
to needle swerve.
Incorrect height or incorrect position, front
and rear
Moving amount, front and rear is ill
balanced.
Replace it with good quality of thread.
Adjust moving amount, front and rear of looper so that
looper contacts the needle at 2/3 height of top of the back.
Refer to needle heat in needle breakage
Align the needle entry to the needle.
Refer to standard adjustment
Make adjustment so that looper does not hit the looper. For
the correction of the contact at looper’s back, adjust the
moving amount, front and rear.
Refer to standard adjustment
Use thicker needle.
Reduce the needle thread tension.
Refer to standard adjustment value.
Check to see the height of needle guard and clearance
between needle guard and needle.
Adjust moving amount, front and rear and correct the
incorrect position of looper’s back and the contact when it
returns.
From
the
library
of:
Diamond
Needle
Corp
