SunStar SWF/B Series User Manual page 38

② When inserting the needle, make sure that the groove is
facing front. Shaft of the needle should be inserted
completely into the needle bar.
[ CAUTION 1 ]
For special threads such as artificial silk, turn the
needle to the right slightly to minimize thread breaks
as shown in [Fig.5-25].
[ CAUTION 2 ]
If the needle is not inserted all the way to the top of
the needle bar hole, timing of the machine will go off,
causing broken needles and thread breaks.
Needle insert hole
Needle groove
[Fig. 5-24]
[Fig. 5-25]