16
Set correctly hook opening according to
SK, par. 3.1.6 and adjust setting of trim-
ming cam according to SK, par. 4.3.
Use thinner needle.
Insert needle according to NP, par. 6.5.
Set according to SK, par. 3.1.3 and 3.1.5.
Set according to SK, par. 3.1.4 and 3.2.3.
Set rear guide, so that it touches slightly
the sewn material with the lowered top
roller.
Increase timing as needed and set the
needle bar height according to SK, par.
3.2.3.
Replace hook.
Set according to NP, par. 6.3.
Thread according to NP, par. 6.1 set
according to NP, par. 6.3.
Thread correctly according to NP par. 6.1.
Set according to SK, par. 3.1.6.
Set wheel feeder height according to SK,
par. 3.6.3.2.1.
Set according to SK par. 3.3.2.
Correct setting of the distance between
needle and hook according to SK par.
3.1.3.
Set guide according to SK par. 3.4.3.
Shift thread limiter to the right according
to SK, par. 3.5.5 or by more than the value
quoted there.
Set tension according to NP, par. 6.3.
Shift thread limiter to the top according
to SK, par. 3.5.5 or more than the value
quoted there.
Use a thicker needle.
4. Stitch skipping.
5. Incorrect stitch locking. Threads are
locked on top side of sewn material.
6. Incorrect stitch locking. Threads are
locked on bottom side of sewn
material and increasing of tension is
of upper thread no help.
7. Stitches insufficiently tightened and
with irregular positioning. Thread
unravelled.
3.4 Upper thread incorrectly caught by
movable trimming knife. Lumps of
thread remaining in hook space.
3.5 Needle too thick with regard to
thickness of thread and sewn ma-
terial.
4.1 Needle incorrectly inserted.
4.2 Too big distance between needle
and hook point.
4.3 Incorrectly set needle hook timing
or needle height.
4.4 Rear needle guide too high - sewn
material lifts when moving the
needle and the hook point does not
catch the upper thread loop.
4.5 Excessively elastic material or ex-
cessively elastic thread.
4.6 Damaged hook point.
5.1 Lower thread tension.
5.2 Incorrect threading and tension
setting of upper thread.
6.1 Upper thread out of tensioning
dishes.
6.2 Opening bobbin case lifter incor-
rectly set (it opens too little).
6.3 Wheel feeder too low - difficult
passage of thread between sewn
material and throat plate.
6.4 Incorrect side setting of the throat
plate post or needle bed shifting-
insufficient gap between needle
and edge of piercing hole in the
throat plate insert from the hook
side.
6.5 Needle guide set too low - sewn
material is pushed against throat
plate and upper thread threadning
is difficult.
6.6 Upper thread insufficiently tensio-
ned when passing through hook.
7.1 Low tension of upper and lower
threads.
7.2 Upper thread insufficiently tensio-
ned when passing through hook.
7.3 Thin needle with regard to thread
thickness.
