Brother BAS-612 Owner's Manual
INSTRUCTION MANUAL
LK3-B438E
Please read this manual before using the machine.
Please keep this manual within easy reach for quick reference.
ELECTRONIC LOCKSTITCH BUTTON SEWER
Thank you very much for buying a BROTHER sewing machine. Before using your new machine, please read the safety instructions below and the explanations given in the instruction manual.
With industrial sewing machines, it is normal to carry out work while positioned directly in front of moving parts such as the
needle and thread take-up lever, and consequently there is always a danger of injury that can be caused by these parts. Follow
the instructions from training personnel and instructors regarding safe and correct operation before operating the machine so
that you will know how to use it correctly.
SAFETY INSTRUCTIONS
1. Safety indications and their meanings
This instruction manual and the indications and symbols that are used on the machine itself are provided in order to ensure safe
operation of this machine and to prevent accidents and injury to yourself or other people.
The meanings of these indications and symbols are given below.
Indications
Symbols
DANGER
CAUTION
................ This symbol ( ) indicates something that you should be careful of. The picture inside the triangle indi-
cates the nature of the caution that must be taken.
(For example, the symbol at left means “beware of injury”.)
................ This symbol ( ) indicates something that you
................ This symbol ( ) indicates something that you
of the thing that must be done.
(For example, the symbol at left means “you must make the ground connection”.)
The instructions which follow this term indicate situations where failure to follow the instructions
will almost certainly result in death or severe injury.
The instructions which follow this term indicate situations where failure to follow the instructions could cause injury when using the machine or physical damage to equipment and surroundings.
must not do.
must do. The picture inside the circle indicates the nature
LK3-B438E Mark II
i
2. Notes on safety
Wait at least 5 minutes after turning off the power switch and disconnecting the power cord from the wall outlet before
opening the face plate of the control box. Touching areas where high voltages are present can result in severe injury.
DANGER
CAUTION
Environmental requirements
Use the sewing machine in an area which is free from
sources of strong electrical noise such as high-
frequency welders.
Sources of strong electrical noise may cause problems with correct operation.
Any fluctuations in the power supply voltage should
be within ±10% of the rated voltage for the machine.
Voltage fluctuations which are greater than this may
cause problems with correct operation.
The power supply capacity should be greater than the
requirements for the sewing machine's electrical
consumption.
Insufficient power supply capacity may cause problems with correct operation.
Installation
Machine installation should only be carried out by a
qualified technician.
Contact your Brother dealer or a qualified electrician
for any electrical work that may need to be done.
The sewing machine weighs more than 47 kg. The
installation should be carried out by two or more people.
Do not connect the power cord until installation is
complete, otherwise the machine may operate if the
foot switch is pressed by mistake, which could result
in injury.
Hold the machine head with both hands when tilting it
back or returning it to its original position.
Furthmore, after tilring back the machine head, do not
push the face plate side or the pulley side from above,
as this could cause the machine head to topple over,
which may result in personal injury or damage to the
machine.
Be sure to connect the ground. If the ground connection is not secure, you run a high risk of receiving a
serious electric shock, and problems with correct
operation may also occur.
The ambient temperature should be within the range
of 5°C to 35°C during use.
Temperatures which are lower or higher than this may
cause problems with correct operation.
The relative humidity should be within the range of 45%
to 85% during use, and no dew formation should occur
in any devices.
Excessively dry or humid environments and dew formation may cause problems with correct operation.
Avoid exposure to direct sunlight during use.
Exposure to direct sunlight may cause problems with
correct operation.
In the event of an electrical storm, turn off the power
and disconnect the power cord from the wall outlet.
Lightning may cause problems with correct operation.
All cords should be secured at least 25 mm away from
any moving parts. Furthermore, do not excessively
bend the cords or secure them too firmly with staples,
otherwise there is the danger that fire or electric shocks
could occur.
Install the belt covers to the machine head and motor.
If using a work table which has casters, the casters
should be secured in such a way so that they cannot
move.
Be sure to wear protective goggles and gloves when
handling the lubricating oil and grease, so that they do
not get into your eyes or onto your skin, otherwise inflammation can result.
Furthermore, do not drink the oil or eat the grease under any circumstances, as they can cause vomiting
and diarrhoea.
Keep the oil out of the reach of children.
ii
LK3-B438E Mark II
CAUTION
Sewing
This sewing machine should only be used by operators who have received the necessary training in safe
use beforehand.
The sewing machine should not be used for any
applications other than sewing.
Be sure to wear protective goggles when using the
machine.
If goggles are not worn, there is the danger that if a
needle breaks, parts of the broken needle may enter
your eyes and injury may result.
Set the needle to the needle up stop position before
turning on the power.
If this is not done, the wiper may strike the needle,
which might cause the needle to break.
Turn off the power switch at the following times,
otherwise the machine may operate if the foot switch
is pressed by mistake, which could result in injury.
• When threading the needle
• When replacing the needle and bobbin
• When not using the machine and when leaving the
machine unattended
Cleaning
Set the needle to the needle up stop position before
turning on the power.
If this is not done, the wiper may strike the needle,
which might cause the needle to break.
Turn off the power switch before carrying out cleaning,
otherwise the machine may operate if the foot switch
is pressed by mistake, which could result in injury.
If using a work table which has casters, the casters
should be secured in such a way so that they cannot
move.
Attach all safety devices before using the sewing
machine. If the machine is used without these devices
attached, injury may result.
Do not touch any of the moving parts or press any
objects against the machine while sewing, as this may
result in personal injury or damage to the machine.
If an error occurs in machine, or if abnormal noises or
smells are noticed, immediately turn off the power
switch. Then contact your nearest Brother dealer or a
qualified technician.
If the machine develops a problem, contact your
nearest Brother dealer or a qualified technician.
Be sure to wear protective goggles and gloves when
handling the lubricating oil and grease, so that they do
not get into your eyes or onto your skin, otherwise inflammation can result.
Furthermore, do not drink the oil or eat the grease under any circumstances, as they can cause vomiting
and diarrhoea.
Keep the oil out of the reach of children.
Maintenance and inspection
Maintenance and inspection of the sewing machine
should only be carried out by a qualified technician.
Ask your Brother dealer or a qualified electrician to
carry out any maintenance and inspection of the
electrical system.
Set the needle to the needle up stop position before
turning on the power.
If this is not done, the wiper may strike the needle,
which might cause the needle to break.
Turn off the power switch and disconnect the power
cord from the wall outlet at the following times,
otherwise the machine may operate if the foot switch
is pressed by mistake, which could result in injury.
• When carrying out inspection, adjustment and
maintenance
• When replacing consumable parts such as the rotary hook
If the power switch needs to be left on when carrying
out some adjustment, be extremely careful to observe
all safety precautions.
Hold the machine head with both hands when tilting it
back or returning it to its original position.
Furthermore, after tilting back the machine head, do
not push the face plate side or the pulley side from
above, as this could cause the machine head to topple
over, which may result in personal injury or damage to
the machine.
Use only the proper replacement parts as specified by
Brother.
If any safety devices have been removed, be absolutely sure to re-install them to their original positions
and check that they operate correctly before using the
machine.
Any problems in machine operation which result from
unauthorized modifications to the machine will not be
covered by the warranty.
LK3-B438E Mark II
iii
3. Warning labels
The following warning labels appear on the sewing machine.
Please follow the instructions on the labels at all times when using the machine. If the labels have been removed or are
difficult to read, please contact your nearest Brother dealer.
1
Hazardous voltage
will cause injury.
Turn off main
switch and wait 5
minutes before
opening this cover.
Hochspannung
verletzungsgefahr!
Bitte schalten sie den
hauptschalter aus und
warten sie 5 minuten,
bevor sie diese
abdeckung öffnen.
2
Un voltage non adapté
provoque des blessures.
Eteindrel'interrupteur et
attendre 5 minutes
avantd' ouvrir le capot
Safety devices
Un voltaje inadecuado
puede provocar las
heridas.
Apagar el interruptor
principal y esperar 5
minutos antes de abrir
esta cubierta.
Eye guard
Finger guard
Moving parts
may cause injury.
Operate with safety de vices .
Turn off main switch before
Thread take-up cover
Thread take-up solenoid cover
Belt cover
Motor cover, etc.
threading, changing bobbin
and needle, cleaning etc.
3
Be sure to connect the ground. If the ground connection is not secure, you run a high risk of receiving a
serious electric shock, and problems with correct operation may also occur.
4
Direction of operation
4
Thread
take-up
solenoid
cover
Finger guard
Eye guard
Motor cover
Thread
take-up
cover
2
Belt
cover
3
1
iv
LK3-B438E Mark II
CONTENTS
1. NAME OF EACH PART ............................... 01
2. SPECIFICATIONS ......................................... 02
2-1. Specifications ....................................... 2
2-2. Program list .......................................... 3
3. INSTALLATION............................................. 06
3-1. Power table ........................................... 6
3-2. Installing the motor ............................. 7
3-3. Installing the motor pulley .................. 7
3-4. Installing the control box .................... 8
3-5. Installing the rubber cushions ............ 9
3-6. Installing the oil pan ............................ 9
3-7. Installing the cushions ......................... 9
3-8. Installing the machine head ............... 10
3-9. Installing the head rest ........................ 10
3-10. Installing the liquid cooling tank,
optional ................................................. 10
3-11. Installing the operation panel ............. 11
3-12. Connecting the ground wire ............... 11
3-13. Connecting the cords ........................... 12
3-14. Installing the V-belt .............................. 13
3-15. Installing the belt cover ....................... 14
3-16. Installing the foot switch ..................... 14
3-17. Installing the motor cover ................... 15
3-18. Installing the spool stand .................... 15
3-19. Installing the button tray ..................... 15
3-20. Installing the eye guard ...................... 15
4. LUBRICATION............................................... 16
4-1. Lubrication points ................................ 16
5. OPERATION .................................................. 17
5-1. Name and function of each
operation panel item ........................... 17
5-2. Operating procedure ............................ 19
6. CHECKING THE SEWING PATTERN ....... 20
7. CORRECT USE......................................... 21
7-1. Selecting the needle and thread ........ 21
7-2. Installing the needle ............................ 21
7-3. Threading the upper thread ................ 21
7-4. Wi ndin g th e lower thread ................... 22
7-5. Replacing the bobbin case and
threading the thread ............................ 23
7-6. Thread tension reference guide ......... 23
7-7. Inserting the button ............................. 25
7-8. Ad jusi tng the b utt on ho lde r ............... 25
7-9. Adjustment by the accessory
spring .................................................... 25
9-2. Lubrication ............................................ 28
9-3. Draining the oil ..................................... 29
9-4. Cleaning the control box air inlet
port ........................................................ 29
9-5. Cleaning the eye guard ....................... 29
9-6. Checking the needle ............................ 29
10.STANDARD ADJUSTMENTS ................. 30
10-1. Adj ust ing t he needle bar height ......... 30
10-2. Adjusting the needle bar lift
amount.................................................. 30
10-3. Adjusting the driver needle guard ..... 31
10-4. Adjusting the needle clearance.......... 31
10-5. Adjusting the shuttle race thread
guide...................................................... 31
10-6. Adjusting the thread take-up
amount.................................................. 32
10-7. Adjusting the movable knife ............... 32
10-8. Adjusting the button clamp lift
amount.................................................. 34
10-9. Adjusting the holding pressure .......... 35
10-10.Ad just ing the position of the
button holder ........................................ 35
10-11.Adjusting the needle up stop
position ................................................. 36
10-12.Adjusting the thread wipper ............... 36
10-13.Checking the input sensor and
DIP switch input ................................... 37
10-14.Checking the input voltage ................. 38
10-15.Clearing all memory settings ............. 38
10-16.Moving stitch patterns ......................... 39
11.USING THE COUNTERS......................... 40
11-1. Using the bobbin thread counter ....... 40
11-2. Using the production counter ............ 40
12.CHANGING FUNCTIONS USING
THE DIP SWITCHES ................................ 41
12-1. Operation panel DIP switches ............ 41
12-2. Setting the presser mode ................... 41
12-3. DIP switches inside the control
box ......................................................... 42
12-4. Using user programs ........................... 43
13.CHANGING SPECIAL FUNCTIONS
USING THE MEMORY SWITCHES ........ 45
13-1. Using the cycle sewing function ........ 47
14.TABLE OF ERROR CODES...................... 49
15.GAUGE PARTS LIST ............................... 51
16.TROUBLESHOOTING ................................. 52
8. SEWING ................................................... 26
9. MAINTENANCE AND INSPECTION ....... 27
9-1. Cleaning the rotary hook .................... 27
LK3-B438E Mark II
17.OPTIONAL PARTS ....................................... 55
1 . NAME OF EACH PART
1. NAME OF EACH PART
i
!5
!0
y
!1
t
!4
!2
o
u
!3
e
q
w
r
Safety devices;
qPower switch !0Finger guard
wControl box !1Eye guard
eOperation panel !2Thread take-up cover
rFoot switch !3Belt cover
tMotor !4Motor cover
yTension release lever !5Thread take-up solenoid cover
uPulley
iSpool stand
oThread take-up lever
1
LK3-B438E Mark II
2 . SPECIFICATIONS
2-1 . Specifications
2 . SPECIFICATIONS
Stitch formation
Maximum sewing
speed
Maximum pattern
size
Needle
Dimensions of
buttons that can be
sewn
Button clamp height
Thread knot
Feed mechanism
Stitch length
Number of stitches
Maximum stitch
number
Work clamp lifter
Single needle lock stitch
2,500rpm
0 - 6.4 × 0 - 6.4 mm
TQ × 1#12
Outer diameter of button 8 - 30 mm
(Use the optional button clamp B for diameters of 20 mm or greater.)
Space between the button holes 0 - 6.4 mm
13 mm max.
Knot tied by needle
R-θ intermittent feed mechanism (pulse-motor driven mechanism)
0.1 - 10.0 mm
Variable (13, 15, 17, 19, 20, 22, 23, 24, 26, 27, 28, 30, 32, 34, 38 stitches
pre-set)
20,000 stitches (including 10,000 stitches which can be added)
Solenoid type
Rotary hook
Wiper device
Thread trimmer
device
Thread take-up device
Data storage method
Number of user
programs
Number of cycle
programs
Number of stored
data
Motor
Weights
Power source
Shuttle hook
Standard equipment
Standard equipment
Standard equipment
P-ROM (Any sewing pattern can be added using BAS-PC/300.)
16
4
49 sewing patterns are set already.
(Up to 100 patterns can be added. Total number of stitches of stored data
which can be added is within 10,000.)
Three-phase 400W induction motor
Machine head: 47kg, Operation panel: 0.6kg,
Control box: 9 - 19kg (depending on destination)
Single-phase 220 - 230V
3-phase 220, 380, 400, 415V
Maximum electric power consumption; 600VA
LK3-B438E Mark II
2
2 . SPECIFICATIONS
2-2 . Program list
Sewing patterns are limited as shown in the table below.
(Any program is available as long as the needle drops down in the hole of the button.)
Program No.
1
2
3
4
5
6
7
23
8
button holes
*1
*1
*2
*2
*2
No. of
2
Sewing
pattern
No. of
threads
6
8
10
12
16
20
6
10
12
No. of
crossover
stitches
__
__
__
__
__
__
__
__
__
No. of
stitches
13
15
17
19
23
27
13
17
19
Standard
sewing length X
3.4mm
0mm
Standard
sewing width Y
0mm
3.4mm
24
25
26
10
11
12
13
27
14
*2
9
*2
*2
3
*2
5-5-5
7-7-7
5-5-5
7-7-7
6-6
8-8
4
8-8
10-10
12-12
__
__
__
__
1
1
3
1
1
22
28
22
28
20
24
26
28
32
2.6mm
3.4mm
2.4mm
3.4mm
*3
6-6
0
26
*3
28
4
15
29
*3
*3
3
8-8
10-10
12-12
LK3-B438E Mark II
0
0
0
30
34
38
2 . SPECIFICATIONS
Program No.
16
17
30
18
19
31
45
20
32
33
button holes
*3
*3
*3
No. of
4
Sewing
pattern
No. of
threads
6-5
8-7
10-9
6-6
8-8
10-10
12-12
6-6
8-8
10-10
No. of
crossover
stitches
1
1
1
1
1
1
1
0
0
0
No. of
stitches
19
23
27
20
24
28
32
26
30
34
Standard
sewing length X
3.4mm
Standard
sewing width Y
3.4mm
*2
21
34
22
35
46
47
48
49
*2
*2*3
*2*3
6-6
10-10
6-6
10-10
6-6
8-8
10-10
12-12
1
1
0
0
1
1
1
1
20
28
26
34
20
24
28
32
2.4mm
3.4mm
3.4mm
3.4mm
*1 Check that the button hole diameter is 2 mm or greater before using the programs.
* 2 Do not use the button lifter spring.
*3 Thread is trimmed after sewing of one side is completed, because there is no crossover thread to be sewn.
To continue sewing to the end, keep the foot switch depressed until sewing of the other side starts, or
press the foot switch once more after sewing of the first side is completed.
LK3-B438E Mark II
4
2 . SPECIFICATIONS
■ The following programs require the solenoid thread wiper (OP).
Program No.
36
37
38
39
40
41
42
43
44
No. of
button holes
*
*
Sewing
pattern
No. of
threads
6-6
8-8
10-10
12-12
4
6-6
8-8
10-10
6-6
10-10
No. of
crossover
stitches
0
0
0
0
0
0
0
0
0
No. of
stitches
26
30
34
38
26
30
34
26
34
Standard
sewing length X
3.4mm
2.4mm
Standard
sewing width Y
3.4mm
3.4mm
* 2 Do not use the button lifter spring.
5
LK3-B438E Mark II
3. INSTALLATION
Table/ legs assembly
Model code
127-V30-00001
3. INSTALLATION
CAUTION
Machine installation should only be carried
out by a qualified technician.
Contact your Brother dealer or a qualified
electrician for any electrical work that may
need to be done.
The sewing machine head weighs more than
47 kg. The installation should be carried out
by two or more people.
Do not connect the power cord until installation is complete, otherwise the machine may
operate if the foot switch is depressed by mistake, which could result in injury.
Hold the machine head with both hands when
tilting it back or returning it to its original position. Furthermore, after tilting back the machine head, do not push the face plate side
or the pulley side from above, as this could
cause the machine head to topple over, which
may result in personal injury or damage to
the machine.
All cords should be secured at least 25 mm
away from any moving parts. Furthermore,
do not excessively bend the cable or secure it too firmly staples, otherwise there is
the danger that fire or electric shocks could
occur.
Be sure to connect the ground. If the ground
connection is not secure, you run the risk
of receiving a serious electric shock, and
problems with correct operation may also
occur.
Install the belt covers to the machine head
and motor.
3-1 . Power table
• Use the power table which has been specially designed
for each sewing machines.
* If using a commercially-available table, process it as
shown in the illustration below.
NOTE:
The thickness of the table should be at least 40 mm, and it should be strong enough to bear the weight and vibration of
the sewing machine.
If the distance A between the insides of the legs is less than 740 mm, move the control box installation position closer
to the motor (B = 247 mm).
Check that the control box is at least 10 mm away from the leg. If the control box and leg are touching, it could cause the
sewing machine to operate incorrectly.
Control Box
Motor
Operation
panel cord
hole
Section A-A
LK3-B438E Mark II
Counterbore depth 23
depth 5
6
3. INSTALLATION
3-2 . Installing the motor
q
u
w
e
q
Install the motor u to the work table with the four accessory bolts q, cushions w, cushion collars e, flat
washers r, spring washers t and nuts y.
At that time, fix by setting bolts q a little to the right
of oval hole on motor.
NOTE:
Tighten the nuts y so that the clearance between the table
and the cushion collars e is approximately 1 mm.
r
t
y
1mm
3-3 . Installing the motor pulley
q
w
Table
e
Place the motor pulley q onto the shaft of the motor
w so that the key groove is aligned, and then tighten
the set screw e so that the center of the V groove in
the motor pulley q is aligned as closely as possible
with the center of the belt hole in the power table.
e
7
LK3-B438E Mark II
3-4 . Installing the control box
3. INSTALLATION
!1
!0
!2
w
e
r
t
y
u
i
o
q
3mm
Table
Cushions
t
Cushion collars
y
Rubber collers
u
Flat washers
i
Nuts
o
!3
1. Remove the 12 screws q, and then open the covers (panel mounting assembly w and main P.C. board
mounting plate e).
NOTE:
When opening the cover, hold it securely so that it does not fall down.
2. Install the control box with the four accessory bolts r, cushions t, cushion collars y, rubber collars u,
flat washers i and nuts o as shown in the illustration above. At this time, leave a gap of approximately
3 mm between the work table and the top of the box.
* Use two nuts o at each installation location, and make sure that both nuts are tightened.
3. Close the covers (panel mounting assembly w and main P.C. board mounting plate e), and tighten them
with the screws q.
* The main P.C. board mounting plate e will be opened again during “3-13. Connecting the cords”, so
provisionally tighten it with the screw q.
4. Install the power switch !0 with the two screws !1.
5. Secure the power switch cord with the three staples !2.
6. Pass the motor cord through the cord hole !3.
LK3-B438E Mark II
8
3. INSTALLATION
3-5. Installing the rubber cushions
w
q
3-6 . Installing the oil pan
q
w
Install the rubber cushions q with the nails w.
1. Insert the tabs of the oil pan w into the holes for
the cushions q, and then secure it in place with
the five nails e so that the oil pan w is not at an
angle.
2. While pushing the oil pan w down from above,
screw in the oil container r.
r
3-7 . Installing the cushions
w
e
Place the two cushions q into the holes in the work
table so that the notches are aligned with the tabs in
the oil pan, and secure them in place with the nails w.
q
9
LK3-B438E Mark II
3-8 . Installing the machine head
q
w
u
3. INSTALLATION
y
17
66
13
r
e
t
1. Insert the head hinges q into the machine head so that they are parallel, and then secure them with the
two set screws w.
2. Place the machine head gently on top of the rubber cushions e and cushions r.
NOTE:
Pull the cords t out as shown in the illustration above in order to prevent them from being clamped by the machine
head.
3. Install the hinge presser y with the two screws u.
3-9 . Installing the head rest
q
Tap the head rest q into the table hole.
NOTE:
Tap the head rest securely into the table hole.
3-10 .Installing the liquid cooling tank, optional
1. Remove the rubber plug, and then push the liquid
w
q
LK3-B438E Mark II
2. Tighten it with the set screw w.
cooling tank q.
10
3. INSTALLATION
3-11 . Installing the operation panel
The operation panel can be installed to either the top or bottom of the work table.
Top of work table
q
e
t
1. Install the rear frame q to the work table (top or bottom) with the four wood screws w.
2. Install the front frame e to the rear frame q with the four screws r.
* The vertical orientation of the front frame e is the same whether it is installed to the top or the bottom of
the work table.
3. Insert the connector cord t into the control box through the hole at the side of the box. Refer to “3-13.
Connecting the cords” for details on connecting the cord.
4. Secure the connector cord t with the staples (in three places).
r
w
Table
Bottom of work table
e
t
q
r
Table
w
3-12 . Connecting the ground wire
Be sure to connect the ground. If the ground connection is not secure, you run the risk of receiving a serious electric shock, and problems with correct operation may also occur.
Red
White
Black
Yellow/Green
CAUTION
Connect to the power switch. However, the
black wire is insulated to the inside of the box
and is not used.
Connect to ground
11
LK3-B438E Mark II
3-13 . Connecting the cords
3. INSTALLATION
q
w
q
!1
!0
Machine head connectors
Connection location
X, Y, Sewing sensor
Synchronizer
Machine specification
select connector
Thread take-up solenoid
Presser solenoid
Thread trimmer solenoid
Pulse motor, Y
!2
r
No. of pins
12-pin
5-pin
8-pin
5-pin
4-pin
4-pin (blue)
P11
Cord mark
z
x
c
v
b
n
!3
P8
P1
P2
P3
o
u
i
e
P4
P5
P6
P7
Connection location on circuit board
P1 (ORG2)
P2 (SYNCHRO)
P3 (SELECT)
P4 (SOL2)
P5 (SOL)
P6 (YPM)
t
y
Pulse motor, X
Operation panel
Upper shaft motor
4-pin
26-pin
3-pin
m
None
None
P7 (XPM)
P8 (PANEL)
P11 (UVW)
1. Gently tilt back the machine head.
NOTE:
After tilting back the machine head, do not push the face side or the pulley side from above.
2. Pass the cords q through the hole w in the work table.
3. Gently return the machine head to its original position.
4. Remove the six screws e, and then open the control box cover (main P.C. board mounting plate r).
NOTE:
When opening the cover, hold it securely so that it does not fall down.
5. Loosen the two screws t,and then open the cord presser plate y in the direction of the white arrow and
pass the cords q through the opening.
6. Loosen the screw o, and then attach the ground cord u for the machine head and the ground cord i for
the operation panel as shown in the illustration.
7. Loosen the screw !1, and then attach the ground cord !0 for the upper shaft motor as shown in the illustration.
8. Securely connect connectors P1 to P8 and P11 as indicated in the table.
9. Secure the cords q with the cord clamps !2 and !3.
10. Close the cord presser plate y in the direction of the black arrow, and secure it by tightening the screws t.
NOTE:
Check that the cords do not get pulled when the machine head is tilted back gently.
11. Tighten the cover (main P.C. board mounting plate r) with the six screws e.
LK3-B438E Mark II
12
3. INSTALLATION
3-14 . Installing the V-belt
A
r
w
Approx.
1mm
Approx. 9-10mm
10N
e
q
1. Gently tilt back the machine head, and then place
the V-belt q into the V grooves on the machine
head pulley w and the motor pulley e.
NOTE:
After tilting back the machine head, do not push the
face plate side or the pulley side from above.
2. Gently return the machine head to its original position.
* Be careful not to clamp the cords at this time.
3. Provisionally install the accessory tension pulley
assembly r with the accessory flat washer, spring
washer and bolt.
4. Adjust the belt tension by moving the tension pulley assembly to the right and left so that there is 9-
-10 mm of deflection in the V-belt q when it is
gently pushed in the middle with a force of approximately 10 N. After adjusting, tighten the bolt
A to secure the left pulley assembly.
5. Move the right tension pulley so that there is a
gap of about 1 mm between it and the V-belt q,
and then tighten the bolt B to secure the right
pulley assembly.
NOTE:
Use brother specified V-belt (belt, VM).
The V-belt q may stretch slightly when it is first used,
B
so adjust the belt tension after about 3,000 cycles of
use.
When above belt tension is week, this will be cause of
following problems;
• Noise & vibration become large.
• Needle up stop position becomes unstable.
• Error message [E-50] is displayed.
Check that the motor is positioned so that the Vbelt is straight. (Fig.1)
13
Sewing
machine
V-belt
Motor
Fig.1
LK3-B438E Mark II
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