3-Thread Chain Stitch (Overlock) - Silvercrest SON 90 A1 Instrucciones De Uso

3-thread chain stitch (overlock)

Figure 59 shows you the stitch pattern for this stitch.
This stitch with a needle and 3 threads is used for tidying of normal fabrics
with an overcast stitch.
By changing the needle position you can obtain a narrow or a wide overcast
seam.
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.
Textiles
blue
light
2.0
material
medium-
3.0
weight
material
heavy
3.0
material
Textiles
blue
light
-
material
medium-
-
weight
material
heavy
-
material
Should the upper looper yarn lie on the underside of the textile (Fig. 60):
• turn the thread tension selector z for the upper looper thread (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. 61):
• turn the thread tension selector for the lower looper thread u (yellow)
to a higher number, or ...
• turn the thread tension selector z for the upper looper thread (red) to a
lower number.
Should the needle thread appear to be too loose (Fig. 62), turn the thread
tension selector for the needle thread (blue r or green t) to a higher
number.
Tensioning the thread
green red yellow
- 2.0 1.0
- 2.0 1.5
- 3.0 1.5
Tensioning the thread
green red yellow
2.0 7.0 2.0
2.5 6.5 2.5
3.5 6.5 2.5
Needle position
Seam width switch
Stitch length
Upper looper element
Correct thread tension
upper looper thread
needle thread
Top
Incorrect thread tensions
upper looper thread
needle thread
Top
upper looper thread
needle thread
Top
upper looper thread
needle thread
Top
- 131 -
S
2 - 4
not necessary
lower looper thread
Underside
Fig. 59
lower looper thread
Underside
Fig. 60
lower looper thread
Underside
Fig. 61
lower looper thread
Underside
Fig. 62