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

3-thread overcast chain stitch (overlock)

Figure 67 shows you the stitch pattern for this stitch.
This stitch with a needle and 3 threads is used for sewing, for example,
decorative edges.
By changing the needle position you can obtain a narrow or a wide overcast
chain 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
4.0
material
Textiles
blue
light
-
material
medium-
-
weight
material
heavy
-
material
Should the upper looper yarn be too loose (Fig. 68):
• turn the thread tension selector for the upper looper thread z (red) to a
higher number.
Should the lower looper yarn be too loose (Fig. 69):
• 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 needle yarn be too loose (Fig. 70):
• turn the thread tension selector for the needle (blue r or green t) to a
higher number.
• turn the thread tension selector for the upper looper thread z (red) to a
lower number.
Tensioning the thread
green red yellow
- 0 4.0
- 0.5 6.5
- 0.5 7.5
Tensioning the thread
green red yellow
1.5 0 5.0
2.5 1.0 7.0
3.0 1.5 8.0
Needle position
Seam width switch
Stitch length
Upper looper element
needle thread
upper looper thread
Top
Incorrect thread tension
needle thread
upper looper thread
Top
needle thread
upper looper thread
Top
needle thread
upper looper thread
Top
- 133 -
S
2 - 4
not necessary
Correct thread tension
needle thread
lower looper thread
Underside
needle thread
lower looper thread
Underside
needle thread
lower looper thread
Underside
needle thread
lower looper thread
Underside
Fig. 67
Fig. 68
Fig. 69
Fig. 70