Baby Lock Lauren (BL450A) Instruction and Reference Guide - Manual (Page 15)

13
ADJUSTING THE PRESSURE ON FABRIC
OVERLOCK SEWING
(1-needle, 3-thread )
This machine can also sew 1-needle, 3-thread overlock
stitching by removing either needle, depending on the seam
width you desire.
This is the standard overlock stitch and is suitable for most
fabrics.
To convert your machine to a wide 3-thread stitch (7.2 mm -
6.2 mm), snip the right needle thread just above the eye of the needle.
Remove the thread from the “yellow” color coded thread guides. Remove the
right needle and tighten the right needle clamp screw. This stitch width is
suitable for sewing heavier fabrics.
To convert your machine to a narrow 3-thread stitch (5 mm - 4 mm), snip the
left needle thread just above the eye of the needle. Remove the thread from
the “red” color coded thread guides. Remove the left needle and tighten the
left needle clamp screw. This stitch width is suitable
for sewing lightweight to medium weight fabrics.
Both seam widths can be adjusted by turning the width
indicator knob. (See page 12 “SETTING SEAM
WIDTH”.)
Increase
Fabric
Weight
Light
Medium
Heavy
Needle Thread
(Left or Right)
Upper
Looper
Thread Lower
Looper
Thread
(Left)
(Left)
(Left)
(Right)
(Right)
(Right)
Correct 3-
thread tension
Top side
of
fabric
Bottom side
of fabric
Lower
Looper
Thread
6.2 mm
The pressure on the foot can be adjusted for different weight fabrics. The
fabric should move along smoothly and evenly without slipping.
Stitches should be uniform in size.
The pressure on this machine is set for sewing medium weight fabrics.
• For sewing light weight fabrics, decrease the pressure (turn screw to left).
• For heavy weight fabrics, increase the pressure (turn screw to right).
NOTE:
This table is a guide for
thread tensions when
sewing with #80 to #90
polyester spun threads.
three thread tension
Use the chart to the right as a guide in setting tension.
Note: Be sure that the thread is passing between the
tension discs.
The illustrations below are examples of stitches which
need adjusting.
Needle thread is too loose. (Clearly
visible on the bottom side of fabric.)
Increase Needle Thread Tension
and/or Decrease Upper and Lower
Looper Thread Tension. Increase Upper Looper Thread
Tension and/or Decrease Lower
Looper Thread Tension.
Upper looper thread crossed on
bottom side of fabric. Lower looper thread crossed on top
side of fabric.
Increase Lower Looper Thread
Tension and/or Decrease Upper
Looper Thread Tension.
Decrease
Upper
Looper
Thread
Needle
Thread
4.0 mm
2.0-4.0
1.5-3.5
2.0-4.0
1.5-3.5
2.5-4.5
1.5-3.5 2.0-4.0
2.5-5.0
2.0-4.0
2.5-5.0
2.0-4.0
2.5-5.0 2.0-4.0
2.0-4.0
2.0-4.0
2.0-4.0
2.0-4.0
2.0-4.0