3-Thread Safety Stitch, Highly Elastic, Imitated - Silvercrest SON 90 A1 Operating Instructions Manual

3-thread safety stitch, highly elastic, imitated

Figure 71 shows you the stitch pattern for this stitch.
This stitch with 2 needles and 3 threads is ideal for lightweight, extremely
stretchy fabrics such as jersey and spandex.
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.
For this type of stitch insert the upper looper element in the upper looper o.
Textiles
blue
light
2.0
material
medium-
3.0
weight
material
heavy
4.0
material
If the lower looper thread is too loose (Fig. 72):
• turn the thread tension selector for the lower looper thread u (yellow)
to a higher number.
Should the left needle yarn be too loose (Fig. 73):
• turn the thread tension selector for the left needle r (blue) to a higher
number.
Should the right needle yarn be too loose (Fig. 74):
• turn the thread tension selector for the right needle t (green) to a higher
number.
Tensioning the thread
green red yellow
Inserting the
1.5
upper looper
element
Inserting the
2.0 0.5
upper looper
element
Inserting the
3.0 1.0
upper looper
element
Needle position
Seam width switch
Stitch length
Upper looper element
0
Left needle thread
Right needle thread
Top
Left needle thread
Right needle thread
Top
Left needle thread
Right needle thread
Left needle thread
Right needle thread
- 26 -
Correct thread tension
Underside
Incorrect thread tension
lower looper thread
Underside
lower looper thread
Underside
Top
lower looper thread
Underside
Top
S
2 - 4
insert
lower looper thread
Fig. 71
Fig. 72
Fig. 73
Fig. 74