Overlock Sewing (2-Needle, 4-Thread); Four Thread Tension - Baby Lock A_LINE Lauren BL450A Instruction And Reference Manual

OVERLOCK SEWING (2-needle, 4-thread)

Your machine will sew overlock stitches and
simultaneously trim the fabric.
It is delivered from the factory preset to sew a 4-thread
overlock stitch.
This machine can also sew 1-needle, 3-thread overlock
stitch by removing one needle. (See page 13 "OVER-
LOCK SEWING 1-needle, 3-thread".)
The 2-needle, 4-thread stitch offers a stronger seam for
some areas of your sewing. It is recommended for most
woven fabrics and clothes that will receive harder wear
and/or frequent washings.

FOUR THREAD TENSION

The stitch quality depends on proper balance between the four thread tensions. The tensions may require
adjustment depending on the type of fabric, heaviness of fabric and size of thread used.
The table below is a guide for adjusting the thread tension.
Note: Be sure that the thread is passing between the tension discs.
Left
Fabric
Needle
Thread
2.5-4.5
Light Weight
2.5-4.5
Medium Weight
2.5-4.5
Heavy Weight
NOTE:
This table is a guide for
thread tensions when
sewing with #80 to #90
polyester spun threads.
The charts below are illustrations of stitches needing adjustment in the thread tension.
Left needle thread is too
loose. (Clearly visible on
the bottom side of fabric.)
Increase Left Needle Thread
Tension and/or Decrease
Upper and Lower Looper
Thread Tensions evenly.
Right Upper
Needle Looper
Thread Thread
1.5-3.5
2.0-4.0
1.5-3.5 2.0-4.0
1.5-3.5 2.0-4.0
Right needle thread is too
loose.
Increase Right Needle
Thread Tension.
Correct 4-thread tension
Bottom side
of fabric
Lower
Looper
Thread
Lower
Looper
Thread
2.0-4.0
2.0-4.0
2.0-4.0
TO INCREASE, turn tension dial to a higher
number.
TO DECREASE, turn tension dial to a lower
number.
Upper looper thread
crossed on bottom side of
fabric.
Increase Upper Looper
Thread Tension and/or
Decrease Lower Looper
Thread Tension.
Top side
of
fabric
Turning thread tension dial
Increase
5
Decrease
Lower looper thread
crossed on top side of
fabric.
Increase Lower Looper
Thread Tension and/or
Decrease Upper Looper
Thread Tension.
Upper
Looper
Thread
Left
Needle
Thread
Right
Needle
Thread
11