Baby Lock Lauren (BL450A) Instruction and Reference Guide - Manual (Page 13)

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