Baby Lock BL4-428 User manual

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L4 424
Four-Thread,, Three-Thread, & Two-Thread, Oaerlock,.
INSTRUCT¡ON BOOKLET
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CONGRATULATIONS!
You are now part of an exciting new era in sewing. As owner of a Baby Lock BL4-428 you have become part of the serger sewing revolutiori,
opening the door to new possibilities in your creativity.
Professional appearance. The Baby Lock gives the quality finish to your garments that you find in even the most
expensive ready-to-wear.
Faster sewing. Because of Baby Lock's high speed capability - up to 1500 stitches per minute - and its ability to
trim, seam and overcast the fabric all in one operation, you will be completing more sewing projects in far less
time.
lncreased sewinq abilitv Difficult-to-handle fabrics and troublesome sewing techniques will no longer pose a chal
lenge. The Baby Lock handles all types of fabric with case.
Your Baby Lock is a high quality, dependable machine, and with proper care will give you many years of sewing enjoyment. We suggest
that you follow your instruction manual as a step-by-step guide io serger sewing. Later, as you become more confident, the manual will
become a handy reference for expanding your ability.
I

CONTENTS
1. Parts of the machine
2. Accessories
3. How your Baby Lock operates
4. Getting ready to sew
4-1 Setting up your machine
4-2 Needles
4-3 Thread
5. Threading method A - Tying on
6. Threading method B - Manual threading
7. Knives
7-1 Disengaging the upper knife . . . .
8. Start serging
9. Stitch length adjustment
10. Stitch wldth adjustment . . .
10-1 To make stitch width
10-2 To make stitch narrower
1 1. Four-thread serg¡ng
12. Overcasting...
13. Turning an outside corner
14. Turning an inside corner
15. Serging curves
16. Seaming
17. Locking ends . .
18. Three-thread serging
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3
4
5
5
5
6
7
Õ
10
11
12
13
't4
14
14
15
16
't6
17
17
't8
18
20
19. Two-thread serging
19-1 To return from two-thread to three-thread serging
19-2 To return from two-thread to four-thread serging
20. Flatlock seam
21. Flatlocktucks.
22. Blind hemming
23. Narrow rolled edging
23-1 Three-thread narrow rolled edging
23-2 Two-thread narrow rolled edging
24. Seaming sheers with rolled edge
25. Lettuce edge .
26. Resetting from narrow rolled edge to four-thread serging
27. Specialty thread .
28. Specialty thread guide
29. Oiling
30. Replacing a needle
31. Replacing a light bulb . .
32. Replacing a knife blade .
33. Replacing the upper knife
34. Presser foot pressure adjustment
35. Machine specifications
36. Trouble shooting guide .
37. Chart for tension adjustment
38. Do's and Don'ts
22
24
24
25
26
27
28
29
30
31
31
32
JJ
34
36
37
37
38
38
39
39
40
41
42
2

1 PARTS OF THE MACHINE
Pressure adjuster
Thread guide switch
Needle
Presser foot
Stitch width
adjusting dial
Side cover
Telescopic thread guide
Left needle thread tensíon
adjuster (Orange)
Right needle thread
tension adjuster (Yellow)
Upper looper thread
tension ad.iuster (Green)
Lower looper thread
tension adjuster (Blue)
Handwheel
Power/Lamp switch
2 ACCESSORIES
lnstruction manual
Curved tweezers
oit ...
Lint brush
Screwdrivers
Spool caps
Thread nets .
N eed les
Lower knife replacement blade
Machine cover
Lower knife clamping screw
Stitch width adjusting dial
1
1
1
1
2
4
4
5
1
1
3
Upper looper
Subsidiary
looper
Subsidiary looper
brass screw
Front cover Stitch finger holder

3 HOW YOUR BABY LOCK OPERATES
A serger (or overlock, as it is sometimes called) is quite different from a conventional sewing machine. Understanding its simple operation will help you use it more
effectively. \
The Baby Lock BL4-428 stitches with one or two needles, but no bobbins. lnstead the lower threads are carried by two metal arms called "loopers". (Figure 1)
As the needles move up and down through the fabric, the loopers carry their threads side to side interlocking them with the needle thread at the seamline. The
looper threads interlock with one another at the edge of the fabric to complete the stitch.
The stitches form around two small metal prongs called "stitch fingers". (Figure 2) These stitch fingers support the edge of the fabric and prevent it from curling
or puckering under the stitches. The stitch fingers can be moved together or apart to vary the stitch width.
As the fabric moves under the presser foot, two cutting knives move in a scissor-like action to trim the edge of the fabric just ahead of the stitches. (Figure 3)
After setting up your machine for the first time, take a few minutes to watch how it sews. Remove the presser foot to get a closer view. Turn the handwheel away
from you and watch the movement of the needles, loopers and knives. Don't worry about stitching on fabric yet. lt does not hurt your Baby Lock serger to stitch
without any fabric.
o
Upper looper
Lower looper
Figure 1
Upper knife
Lower knife
Figure 3
4
sNeedle plate
fi ngers
SÕAdjustable
stitch finger
Figure 2

4 GETTING READY TO SEW
4-1 Setting up your machine
After removing the styrofoam packing materials from the box, gently liftyour Baby Lock serger by grasp-
ing the handle on the top of the machine. Place the machine on a serger table or other level work surface.
Please protect fine furniture surfaces to avoid scratches or stains.
Raise the telescopic thread guide to its highest position. (Figure 4) You will find that the shaft can be
rotated left and right. Do so at each stopper level until each section '1clicks" into locked position.
Place the foot control on the floor under the sewing table. First plug the terminal into the machine, then
insert the plug into a wall outlet. The on/off sw¡tch is located on the lower right side of the machine.
Make sure power is always off when the machine is not in use. (Figure 5)
To open the front cover. place your thumb into the indentation at the lower right corner and slide the
cover to the right. Then rotate the cover forward to provide access to the loopers, knives and thread guides.
(Figure 6)
The side cover is opened by gently pushing its front edge toward the left. lt is hinged in back and will
swing open for easy cleaning and for stitch length adjustment (Figure 6)
4-2 Needles
Your Baby Lock serger is fitted with a size 1 1 industrial sewing machine needle (Organ DC x 1F) which is
suitable for all light-to medium-weight fabrics. To sew very heavy fabrics you will want to change to a size
14 needle. (See page 37 for instruction to change needles)
The semi-ballpoint design of the industrial needle allows you to use the same needle for sewing knits as
well as wovens. lts quality and strength are specifically designed for high-speed sewing. An industrial needle
will give perfect stitch formation through many hours of sewing.
Telescopic
thread stand
Stopper
Stopper Figure 4
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Front cover @Figure 6
5
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Terminal box
<r
Power/Lamp Switch
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Power
supPlY Figure 5
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4-3 Thread
Many types of good quality thread can be used on your Baby Lock serger, but 100% long-staple polyester thread cross-wound on a conewill consistently provide
the best stitch performance. Because the threads pass through many thread guides at a high speed, it is important that the thread be high strength, uniform in
thickness and produce a minimum of lint.
Good quality cotton or cotton-covered polyester threads sew well, though they d'o produce more lint and create the need to clean the machine more frequently.
They work well for overedging and seaming. For narrow rolled edging, this thread may be too weak or loo fuzzy for the desired effect. Poor grades of these threads
can result in frequent fraying and breaking.
Threads of other fiber content and weight may be used as well, especially for decorative effects. Keep in mind their thickness and strength, because these factors
determine the ease w¡th which thread passes through the thread guides, tensions, needles and loopers. For more information on sewing with specialty thread. see
page 34 and 35.
* Cone thread
When using cone thread, place each cone securely over the cone holders on the thread stand of the machine.
You may need to place one hand under the thread while positioning the cone, in order to prevent bending the
stand. These cone holders keep the cone from spinning and allow the thread to feed off evenly.
* Spool thread
Spool caps are provided for use with spool thread. These caps cover any notches or serrated edges on the spool
itself, and allow the thread to feed off evenly. Snap a spool cap into the hole on the top of the thread spool.
Place the thread on the spindle. The cap may cause the thread to be suspended from the top of the spindle.
Do not try to force the cap down onto the spindle itself. (NOTE: lt is not necessary to remove the cone holders
when using spool threads.) (Figure 7)
* Thread nets
The nets can be placed over cones or spools when the thread has a tendency to "drop off" its holder while
sewing. For most threads the nets are not necessary, but they are helpful with nylon, rayon or silk threads.
(Figure 8)
Spool cap
I thread
Cone holder
Figure 7
Cone spool thread Thread net
Figure 8
6

5 THREADING METHOD A-TYING ON
The fastest and easiest way to thread your Baby Lock serger is to cut off the unwanted thread and
tie its end to the beginning of the new thread, as follows:
1. Clip the existing thread strands just above each cone/spool. (Figure g)
2. Remove the old thread cones and position the new ones on the stand. Make a square knot to tie
each old thread end to its corresponding new thread.
3. Clip the needle thread(s) just above the eye of the needle(s). Attempting to pull the knot through
the eye can bend or break the needle. (Figure 9)
4. Make a few stitches to separate the thread chain and discard the needle thread tails. Gently pull
the looper threads - one at a time - until each knot passes through the entire threading path
of the machine. Snip off the knots and discard the old thread ends.
(HINT: As you pull each thread with your left hand, use your right hand to pull the tension
ring forward slightly, making it easier for the knot to pass through) (Figure 10)
5. Pull the needle thread(s) through in the same manner and use the curved tweezers to rethread
the needle(s).
6. Place all threads under the back of the presser foot, lower the foot and sew a few stitches to
start the chain. (Figure 1 1 )
e
Figure 9
Figure 1 0
7
Tension disc
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Figure 1 1
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lf thread breaks or run out, it will be necessary to rethread manually. The thread guides are marked with color coding, and a color-coded thread chart is located
on the backside of the front cover. lt is important that the threadinq be done in the following sequence'
Plabe the first thread on the third spindle of the thread holder, the one colored
green. Beginning with its corresponding eye on the telescopic thread guide, thread
.tt grr.n color-coded guide, including the tension discs and end with the upper
2. Place the next thread on the far-right (blue) spindle and thread in the same
manner, following the blue color-coded thread path and end with the lower looper
(Figure 12)
NOTE: To use the convenient self-threading looper,
turn the handwheel away from you to bring the
looper to its far-lef.t Position'
Hook the thread through guide "4". (Figure 14)
Slide the thread along the left arm of the looper,
catching it in the metal clip. Pull up any slack thread.
Turn the handwheel to bring the looper to the far
right.
Thread the lower looper eye and bring the thread
under the upper looper and under the back of the
presser foot. (Figure 15)
looper. (Figure 12)
NOTE: Be sure to pull each thread securely between
the discs of its tension adjuster. (Figure 13)
Figure 13
Figure 15
AFigure 14
I
6 THREADING METHOD B.MANUAL THREADING
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Figure 12

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3. Place thread on the second (yellow) spindle and follow the yellow-colored path,
ending with the right needle. Thread the eye of the needle front to back. (Figure
16)
4. Place thread on the far left (orange) spindle and follow the orange color-coded
path, ending with the left needle. Thread the eye of the needle front to back.
(Figure 16)
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Figure 16
NOTE: Each needle thread must catch in its respec-
tive guide and under one side of the thread plate.
(Figure '17)
Figure 17
b. Place all threads under and to the left of the presser foot and make a few stitches
to begin the chain. (Figure 18)
IMPORTANT: lf a looper thread breaks or runs out, while the other threads re-
maln intact, it is necessary to follow this rethreading sequence:
'l . Unthread the eyes of the needles.
2. Rethread the looper.
3. Rethread needle eyes.
lf you forget to unthread/rethread the needle eye, thread will be wrapped around
the lower looper out of sequence and, when you begin to sew, the looper thread will
break. The needles must alwavs be threaded last.
9Figure l8

, --- : -.. "*,. ' --::: ---:---' --:-'-
7 KNIVES
Two blades located at the right of the needle plate trim the fabric edge just ahead of the stitching.
Unlike household knives, they are approximately 1116" (1.5mm) thick and pose no danger in handl-
ing. Their cutting power is derived not from sharpness, but from the angle of the precision-ground
edges.
Make sure you are alwayes sewing with clean, sharp knife blades. The feeding action of the machine is
dependent on the knives being in good condition. Never sew over pins with your serger. Doing so
would damage both blades and make replacement necessary.
The upper knife is made of an especially hard steel and should remain sharp for a long time, probably
many years. The lower knife is made of a softer steel and will require periodic replacement. The
frequency of replacement is determined by how often you sew, how clean you keep your serger and
the types of fabric you sew. Synthetic, metallic and hard-finish fibers cause more wear to the knife
blades than do softer natural fibers.
Upper Needle
plate
knife
Lower
knife
Figure 19
When you notice the fabric not feeding readily or the edges of the fabric not cleanly cut, replace the lower knife (See page 38).
The upper knife can be moved out of cutting position when trimming is not required. The lower knife is in a fixed position and remains that way. even when cutting
is not desired.
10

7-1 Disengaging the upper knife
1. Open the front cover of the machine.
2. With your left hand, firmly push the upper knife holder arm to the righç then rotate the knife
holder knob clockwise with your right hand until the knife is raised to its highest position. You
will feel it "snap" into a locked position.
3. Close the front cover
As you sew with the upper knife disengaged, be sure to align the fabric edge with the right edge of the needle plate as it is fed under the presser foot. lf you fail to
do this, the fabric edge will become entangled with the loopers and could result in damage to the machine. Should a"fabricjam" occur, stop sewing immediately.
Raise the needle and the presser foot, and use the tweezers to free the fabric from the loopers. lf necessary, remove the presser foot for better access.
To return the upper knife to cutt¡ng position, push the upper knife holder arm to the right and rotate it counter-clockwise until the knife is completely down and
resting firmly against the lower blade. You will feel it "snap" again into cutting position.
Upper knife
der arm
Push
+
\
Upper ti,
Upper knife
holder knob
Figure 2O
11

8 START SERGING
When sewing on your Baby Lock serger you may leave the presser foot in the "down" position for most sewing applications. Begin by placing fabric under the
tip of the presser foot. As you step on the foot control, the feed dogs will move the fabric under the foot. (Figure 21l' At the end of a seam, do not raise the presser
foot. Continue sewing off the fabric until a 3" (8cm) thread chain has formed, then clip the thread. (Figure 22) You should only need to raise and lower the presser
foot when sewing with thick, spongy or lofty fabrics or when precise positioning is required.
For conventional seaming. the needle should enter the fabric 5/8" (1.5cm) from the cut edge. Your serger has a guide printed on the front cover to help you feed
the fabric accurately into the machine. (Figure 23) The orange line is 5/8" (1.Scm) from the left-hand needle. The yellow line 518" (1.Scm) from the right-hand
needle.
Figure 21 Figure 22
R ight 5/8 R
Left needle------.¡ IL
lf
tr
tl gure 23
* To clear stitch f ingers.
1. Raise the presser foot and the needles to highest position.
2. Pull a little slack in the two needle threads just above the eye. (Figure 24)
3. Gently pull thread chain from behind the presser foot untíl threads slip
off the stitch fingers. (Figure 25)
As you sew you will quickly discover that maneuvering the fabric is a little differentfrom conventional sewing. This is caused by the way stitches form around the
stitch fingers. Learning to clear the stitch fingers will make serger sewing easier.
o
25
Figure 24
)
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12

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9 STITCH LENGTH ADJUSTMENT
Your serger is pre-set at 3mm stitch length. This equals about 10 stitches per inch, which is ideal for seaming and overedging on most fabrics. For narrow rolled
edging or for seaming on very light fabrics you may prefer a shorter stitch length. Heavier fabrics or special operations like gathering may require lengthening the
stitch.
The stitch length indicator is located on the handwheel at the right of the machine. The number "l" represents the shortest setting; number,,S" is the longest
stitch.
1. Raise the presser foot, open side cover.
2. With your left forefinger, push in on the red stitch length button firmly. With your right hand. turn the handwheel away from you until the red button fits into
the groove of the stitch length dial. You will feel it "snap" into place. (Figure 26)
3. Continue to hold the red button iri, and turn the handwheel in either direction necessary to bring the desired stitch length number in line with the red indicator
on the machine. (Figure 27)
.M ed indicator
length number
ìcFigure 27
1M234*5
Position for
1mm narrow rolled
hemming (1.Smm) 2mm 3mm 4mm Needle lowest
position mark 5mm
Stitch length button (red) Turn
Sti'ich length dial Groove Figure 26
'::¡g
ru
F
4. Release the button and close the side cover 13

1
1
1
2
J
4
5
1O STITCH WIDTH ADJUSTMENT
This machine is pre-set for st¡tch width of 5.5mm (about 1/4"). Stitch width can be widened by moving the stitch fingers further apart, or narrowed by moving
them closer together, within a range from 4.7mm - 7.Smm (about 3116" - 5116"1. Adjust the width according to the type of fabric used and the finished stitch
appearance desired. Loosely woven fabrics require a wider stitch, while you may prefer a narrow stitch on knitted, tightly woven or sheer fabrics.
\
0-1 To make stitch wider Stitch w¡dth window
ñ
Stitch width dial
Figure 28
1O-2 To make stitch narrower
Simply turn the stitch width dial toward you until the yellow indicator matches the desired stitch width line in the needle plate window. (Figure 29)
4:1 r
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n
Yellow
line IF
n
4.7mm 5.5mm 6.5mm 7.5mm Figure 29
6.5
IF
n
Stitch width
dial
NOTE: Stitch width can be further reduced by removing the left-
hand needle front the machine. The machine will form a 3-thread
stitch that is 2.2mm narrower than the size indicated by the number
in the stitch width window. (Figure 30)
Open the front cover, raise the needle bar and presser foot.
Use your finger or tweezers to pull a small amount of slack in the needle thread just above the
eye of the needle. Gently tug back on the thread chain until the threads clear the stitch fingers.
Rotate the upper knife to its highest position. (See page 1 1)
Turn the red stitch width dial away from you until the yellow stitch width indicator matches the
desired width line in the needle plate window. (Figure 29)
Lower presser foot, upper knife and close the front cover.
4_7\ r
-llr
n
Yellow
line -l /t-
-lllr
n
6.5
F
n
I
2.5mm 3.5mm 4.3 mm 5.3mm Figure 30
Stitch width
dia I
14

--t-
11 FOUR-THREAD SERGING
Your Baby Lock is pre-set for four-thread serging, the most common mode of serger sewing. lt
provides a very durable, yet fully stretchable seam or overedge on all types of fabric.
With tensions properly set, the lower looper thread forms a flat, non-rolling pattern of overcasting
stitches on the underside of the fabric. The upper looper thread forms a similar pattern on the top
side and these two threads lock together evenly over the cut edge. The left needle thread interlocks
with the two looper threads at the stitch¡ng line to create the seam. The right needle thread, visible
from the top side of the seam, interlocks with both loopers to add durability. (Figure 31)
The tension on each thread is controlled by its color-coded tension dial. Each dial turns multiple
revolutions to allow maximum control of the stitch. Turn the dial to the right (clockwise) to tighten
or increase the tension; turn it to the left (counter-clockwise) to loosen or decrease tension. The
position of the yellow indicator along the shaft of the tension ring indicates the numerical tension
setting. The chart on page 41 indicates the suggested number ranges for four-thread stitching. Note
on this chart specific settings for your own machine.
The pictures below illustrate some incorrect thread tension for four-thread stitching and the necessary
adjustments to correct them.
Yellow
i nd¡cator
Figure 31
Perfect Seam - 4-thread
Right needle thread
Left needle thread
Face
Back Upper
looper
th read
Lower
looper
th read
Unbalanced
Lower looper thread
over the face round
Back
Face
Tighten
Orang€
Adjuster Elue Adjusrer
Unbalanced
Upper looper thread laps round
over the back
Back
Adjusrer Blue
Adjusler
Face
Unbalanced
Right needle thread too loose
Back
Orange
Adjusrer Green
Adjus¡er Blue
Adjuster
Tighten
Face
Unbalanced
Left needle thread too loose
Back
Green
Adjuster Blue AdjusÈr
Face
Figure 32 Fisure s3 1 5Figure 34 Figure 35

12 OVERCASTING
When constructing a garment with 5/8" (1.5cm) pressed-open seams, it is easiest to finish seam
allowances by serging the edges of each pattern piece before stitching any seams' since pattern
notches will be trimmed away during serging. use a water-soluable pen to mark the location of any
match¡ng points.
To overcast, place the fabric in front of the presser foot with the cut edge aligned with the right
edge of the needle plate. (Figure 36) As you stitch, continue to guide the fabric along the needle
plate edge. lf the upper knife is in cutting position, the edge of the fabric will be "shaved" smooth
but not cut away. Straight stitch the seams on your conventional machine and press open as usual'
1. sew along one edge until you reach the corner. Make one stitch off the edge of the fabric'
2. Clear the st¡tch fingers (See page 12) and rotate the fabric around the corner' Reposition the
needle just below the previous row of st¡tches'
3. Lower the presser foot and continue stitching'
NOTE: lf a loose thread loop forms at the corner, it is caused by too much slack in the needle
thread when clearing stitch fingers. Try again . . . corners take a litfle practice'
Figure 36
Figure 37
13 TURNING AN OUTSIDE CORNER
16

/
14 TURNING AN INSIDE CORNER
1. Clip 1/$" (3mm) into corner.
2. Align the fabric edge with the right edge of the needle plate and stitch unt¡l the knife blade - not
the needle - is in the corner.
3. Lower the needle into the fabric and raise the presser foot. Maneuver the fabric until the cut edge
is straight and a pleat forms in the fabric to the left of the presser foot. (Figure 39)
4. Lower the presser foot and continue stitching the straightened edge. The pleat will disappear
after stitching.
15 SERGING CURVES
To serge around inside or outside curves, handle fabric as you would in conventional sewing, but
guide the fabric into the knife, not the needle. Remember, cutt¡ng takes place before stitching.
Also, since the longer serger presser foot holds the fabric more securely, you may need to raise and
lower the foot several times to work around a very t¡ght curve.
Figure 38
)
Figure 39
17

16 SEAMING
You will find that ¡t is not necessary to finish many garment with 5/8" ('l .5cm) pressed-open seam.
lnstead, seam with your serger and press the seam allovùance to one side. This method is extremely
quick, and gives a lovely finish on most light and medium-weight fabrics, both knitted and woven.
Use the marks on the front cover of your serger to align the fabric for the desired seam width. The
orange line indicates 5/8" (1.Scm) position for four'thread seaming' (Figure 40)
Keep your eye on the edge of ihe fabric to make sure it feeds in aligned with the appropriate mark.
Do not watch the needle. lf the fabric feeds in accurately, the needle will automatically seam in the
right place.
17 LOCKING ENDS
The serger stitch will not readily unravel, so in most instances it is not necessary to secure the ends
of the stitching. When you do, though, select one of these three methods:
A. Leave a 3" (7-8cm) chain, separate the threads and the knot.
B. Apply a dot of seam sealant (Fray CheckTM ) on the threads at the edge of the fabric. Allow to
dry and cut off excess thread.
C. Leave a 3" (7-8cm) chain and use a large-eyed needle to carry the chain back under the serged
stitches.
)
K
L
R
I
lIFigure 40
18

D. Sew over the previous stitches (similar to back-stitch¡ng).
* At the beginning of a seam:
1. Sew 3-4 stitches (about 1/4";6mml into the fabric and stop.
2. Raise the presser foot; lower the needle to securg fabric.
3. Move the chain around under the presser foot so that it aligns with the seamline of the fabric.
4. Lower the foot and continue sewing, catching the chain in the stitches.
* At the end of a seam:
1. Sew one stitch off the fabric edge.
2. Clear the stitch fingers. (See page 12i
3. Turn the fabric over and reposition under the presser foot with the needle at the seam edge.
4. Lower the presser foot. Sew 5-6 stitches (about 112";1.3cml over the previous stitches and
chain off the fabric. Be careful not to let the knife cut ¡nto the original stitches. Figure 42
Figure 43
Figure 44
Figure 41
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