Silvercrest SON 90 A1 - Manual (Page 29)

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4-thread safety stitch, highly elastic, imitated
Figure 75 shows you the stitch pattern for this stitch.
This stitch with 2 needles and 4 threads is ideal for medium to heavy,
stretchy fabrics such as double-knitted materials and swimwear.
It is suitable for combining two materials and neatening the edges at the
same time.
Adjust the thread tension selectors r t z u to the appropriate values
(see table) then sew a test seam on the material being used.
Should the upper looper yarn lie on the underside of the textile (Fig. 76):
• turn the thread tension selector for the upper looper thread z (red) to a
higher number, or ...
• turn the thread tension selector for the lower looper thread u (yellow)
to a lower number.
Should the lower looper yarn lie on the upperside of the textile (Fig. 77):
• turn the thread tension selector for the lower looper thread u (yellow) to a
higher number, or ...
• turn the thread tension selector for the upper looper thread z (red) to
a lower number.
Should the left needle yarn be too loose (Fig. 78):
• turn the thread tension selector for the left needle r (blue) to a higher
number.
Should the right needle yarn be too loose (Fig. 79):
• turn the thread tension selector for the right needle t (green) to a higher
number.
Textiles
Tensioning the thread
blue green red yellow
light material 2.5 2.0 2.5 2.0
medium-
weight
material
3.0 2.0 3.0 2.0
heavy
material
4.0 2.5 4.0 2.5
Needle position
Seam width switch S
Stitch length 2 - 4
Upper looper element not necessary
Correct thread tension
Top Underside
Incorrect thread tension
Right needle thread
lower looper thread
Left needle thread
upper looper thread
Top Underside
Right needle thread
lower looper thread
Left needle thread
upper looper thread
Top Underside
Right needle thread
lower looper thread
Left needle thread
upper looper thread
Top Underside
Right needle thread
lower looper thread
Left needle thread
upper looper thread
Fig. 76
Fig. 77
Fig. 78
Fig. 79
Top
Underside
Right needle thread
lower looper thread
Left needle thread
upper looper thread
Fig. 75
IB_64780_SON 90 A1_LB6 08.03.2011 17:22 Uhr Seite 27