Brother MD-602 User manual

MD-600 Series
AC Servomotor for Industrial Sewing Machines
SERVICE MANUAL
MD-602 (Single-Phase Power Specifications)
MD-612 (Three-Phase Power Specifications)

Contents
SAFETY INSTRUCTIONS
SAFETY INDICATIONS AND THEIR MEANINGS................................................................... i
CAUTIONS WITH REGARD TO SAFETY ................................................................................ ii
WARNING LABEL .................................................................................................................... iii
Outline
1. Outline............................................................................................................................... 1
2. Operation panel and options .......................................................................................... 2
3. Model configuration ........................................................................................................ 3
4. Explanation of the name plate ........................................................................................ 4
Instruction
5. Installation........................................................................................................................ 5
5.1 Installing the motor to the work table................................................................... 5
5.2 Attatching the belt .................................................................................................. 5
5.3 Installing the belt cover .......................................................................................... 6
5.4 Connecting the connecting rod ............................................................................. 6
5.5 Adjusting the belt cover safety mechanisms ....................................................... 6
5.6 Connecting the cords.............................................................................................. 7
5.7 Installing the head lamp ......................................................................................... 9
5.8 Connecting the external operational panel .......................................................... 9
6. Adjusting the treadle unit ............................................................................................... 10
6.1 Operating the treadle.............................................................................................. 10
6.2 Adjusting the treadle .............................................................................................. 12
6.3 When using the automatic pressor foot lifter device........................................... 12
7. Using the control box...................................................................................................... 13
7.1 Before turning on the power switch...................................................................... 13
7.2 Power switch and the power indicator ................................................................. 13
7.3 Setting the sewing speed ....................................................................................... 13
7.4 Control box DIP switch setting procedure ............................................................ 14
7.5 Description of functions ......................................................................................... 15
7.6 Periodic checks........................................................................................................ 17
8. Connecting options ......................................................................................................... 18
8.1 Connecting the pedal for standing operations ..................................................... 18
8.2 Connecting the material edge sensor ................................................................... 20
9. Using the operation panel F-40 ...................................................................................... 21
Maintenance work
10. Changing the head settings............................................................................................ 23
10.1 Setting the motor pulley size and DIP switches for the head ............................. 23
10.2 Setting the DIP switch maximum speed setting for the head............................. 23
10.3 Setting the control box head setting for the head ............................................... 24

10.4 Setting the control box speed setting for the head ............................................. 25
11. Changing the function settings ...................................................................................... 26
11.1 Example for changing the memory switch setting .............................................. 26
11.2 Example for changing the parameter setting....................................................... 26
12. Adjustments ..................................................................................................................... 27
12.1 Synchronizer Model DB2-B737, B748, B774, B791............................................... 27
13. Troubleshooting guide .................................................................................................... 28
13.1 Error display and details ........................................................................................ 30
13.2 Control box troubleshooting guide ....................................................................... 31
13.3 Checking the machine solenoids........................................................................... 33
13.4 Checking the motor ................................................................................................ 33
14. VR1 & VR2 setting of treadle unit .................................................................................. 34
Technical Material
15. Explanation of each mode .............................................................................................. 36
15.1 Initialization mode .................................................................................................. 36
15.2 Head setting mode.................................................................................................. 37
15.3 Memory switch setting mode and parameter setting mode, etc........................ 38
15.4 Stitching speed setting mode ................................................................................ 40
16. Operational instructions ................................................................................................. 41
16.1 When the power SW is ON .................................................................................... 41
16.2 When the power SW is OFF ................................................................................... 41
16.3 Operation of the pedal............................................................................................ 41
16.4 While running.......................................................................................................... 41
17. Memory switch list .......................................................................................................... 42
18. Parameter list ................................................................................................................... 47
19. Panel display table........................................................................................................... 51
20. How to remove the control box ..................................................................................... 52
Control box block diagram ..................................................................................................... 53
Control PCB assembly diagram ............................................................................................. 54
Control PCB circuit diagram (1/3) (2/3) (3/3).......................................................................... 55
Power PCB assembly diagram (1-110/120) ........................................................................... 58
Power PCB circuit diagram (1-110/120) (1/2)......................................................................... 59
Power PCB assembly diagram (1-220/230-240) .................................................................... 60
Power PCB circuit diagram (1-220/230-240) (1/2).................................................................. 61
Power PCB assembly diagram (3-220) .................................................................................. 62
Power PCB circuit diagram (3-220) (1/2)................................................................................ 63
Power PCB assembly diagram (1-230(CE)) ........................................................................... 64
Power PCB circuit diagram (1-230(CE)) (1/2)......................................................................... 65
Power PCB circuit diagram (2/2) ............................................................................................ 66
Panel PCB assembly diagram ................................................................................................ 67
Panel PCB circuit diagram ...................................................................................................... 68
Treadle PCB assembly diagram, circuit diagram.................................................................. 69

iMD-602, 612
Thank you for purchasing this Brother general-purpose sewing machine motor. Before using the motor, please be sure to read
the Safety Instructions and the explanations of how to use the motor which are contained in this manual.
Furthermore, because we are continually improving our products as a result of continuing research, the specifications for the
product which you have purchased may differ slightly from those listed in this manual.
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
The symbols which are used in this manual and their meanings are shown below.
WARNING Failure to observe the instruction which appears after this indication while using the motor
will result in death or severe injury to the user.
CAUTION Failure to observe the instructions which appear after this indication while using the motor
may result in slight to moderate injury to the user, or physical damage.
This symbol is used to indicate general actions which you must do.
This symbol is used to indicate the danger of electric shocks.
This symbol is used to indicate general cautions that should be observed.
This symbol is used to indicate that the ground connection must be made.

ii
MD-602, 612
Do not use the motor near sources of strong electrical interference. If the motor is installed in a location which is close
to sources of strong electrical interference such as high-frequency welders, it may cause problems with correct opera-
tion of the sewing machine.
Disconnect the power cord plug from the wall outlet before installing the motor.
The motor and control box weigh approximately 13 kg. Take care not to drop them on your feet when installing or
removing them from the work table.
Be sure to tighten the nuts securely.
If they are not tightened properly, it could cause the sewing machine to vibrate or shift its position while sewing.
Turn off the power switch and wait for the power indicator on the panel display to turn off before connecting and
disconnecting any of the connectors.
Turn off the power switch before inserting or removing the AC power cord plug.
Be sure to connect the power supply to a secure ground. If the ground is not securely connected, electric shocks may
result.
Use a lamp which is rated at 6 V AC and 20 W or less as the head lamp.
If a lamp with a higher rating than this is used, it could cause the lamp wires and the transformer to overheat and burn
out.
Confirm that the power supply matches the motor and the control box specifications before turning on the power switch.
The motor, control box or sewing machine could be damaged if the supply voltage is too high.
Do not clamp the cords inside the control box when closing the control box cover.
Turn off the power switch before connecting the cords, otherwise damage to the control box, synchronizer, operation
panel or material edge sensor may result.
Any fluctuations in the power supply voltage should be within ±10% of the rated voltage for the motor.
Voltage fluctuations which are greater than this may cause problems with correct operation of the sewing machine.
Use a power supply with a capacity which is in excess of the motor power capacity.
Insufficient power supply capacity may cause problems with correct operation of the sewing machine.
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 of the sewing machine.
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 of the sewing
machine.
Avoid exposure to direct sunlight during use.
Exposure to direct sunlight may cause problems with correct operation of the sewing machine.
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 of the sewing machine.
CAUTION
2. CAUTIONS WITH REGARD TO SAFETY
Following is a compilation of all the warnings and cautions which appear throughout this manual.
WARNING
Wait at least 5 minutes after turning off the power switch before opening the cover of the control box. Touching areas
where high voltages are present can result in severe injury.

iii MD-602, 612
3. WARNING LABEL
Hazardous voltage
will cause injury.
Turn off main
switch and wait 5
minutes before
opening this cover.
Un voltage non adapt
provoque des blessures.
Eteindrel’interrupteur et
attendre 5 minutes
avantd’ ouvrir le capot
Hochspannung
verletzungsgefahr!
Bitte schalten sie den
hauptschalter aus und
warten sie 5 minuten,
bevor sie diese
abdeckung ffnen.
Un voltaje inadecuado
puede provocar las
heridas.
Apagar el interruptor
principal y esperar 5
minutos antes de abrir
esta cubierta.
The warning label shown below is affixed to the cover of the control box. Please follow the instructions on the label at all
times when using the motor. If the label has been removed or is difficult to read, please contact your nearest Brother dealer.
Warning label

1
MD-602, 612
1. Outline
1.1 Features
•Thread trimming motor MD602/MD612 is a low-priced version of the MD601/611.
•Start tacking (2 to 9 stitches) and end tacking (2 to 9 stitches) are possible even without the operation panel (option).
•Voltage specifications for the single-phase 100V system, single-phase 200V system and 3-phase 200V system are avail-
able.
•The rated output is 400W.
•The motor torque has been greatly increased compared to the MD601/611.
1.2 Combination with Brother sewing machines
1. Single needle lockstitch machines (forward rotation)
B737, (B201) B791, B774, B722, B724, B748A, B798, B728, B772A, B778A, B781, B852, B853, B854, B883
2. Twin needle lockstitch machines (forward rotation)
B842, B872, B845, B875, B847, B848, B837, B877, B878
3. Overlock machine (reverse rotation)
(Note) The motor connections do not need to be changed to enable reverse rotation.
4. Post-type sewing machine (forward rotation)
P73, P81, C51
1.3 Options
•Operation panel F-20, F-40, F-100
•Material edge sensor II, material edge sensor IV, B sensor, bobbing thread detector
•Standing work pedal (variable speed pedal, 2-speed pedal)
1.4 Input/output
•Solenoid output: Four outputs (thread trimming, thread wiper, reverse run, presser foot lift) + one output for options
1.5 Miscellaneous
•Lamp terminal block and fuse mounted on control PCB.
•Only high-speeds are set with the head setting mode.
•Incompatible with magnetic synchronizer.

2MD-602, 612
2. Operation panel and options
Attachable operation panel F-20 (X-20)
F-40 (X-40)
F-100 (X-100)
Attachable options Standing work pedal
Material edge sensor (Connect to S2 operation panel and use)
(Note 1) A built-in type panel for B737 and an external type (twin needle, etc.) F-panels are available.
(Note 2) The X-panels can be used with the MD600 Series, but these panels do not have the stitching speed switch
[].
(Note 3) The E-panel for the MD800 series cannot be used with the MD600 Series.
Assembly cord for standing work
Standing treadle 40 variable speed #6 J80081-040
Standing treadle two speed #8 J80380-040
J80630-001
Foot plug J02824-001
Operation panel
Sewing machine Installation Type Code no. of
model type operation panel
F-20 137-207-711-11
B737MK II built-in F-40 137-207-712-11
F-100 137-207-713-11
BF-20 137-207-811-11
B201 built-in BF-40 137-207-812-11
BF-100 137-207-813-11
Operation panel F-20 137-207-711-10
(without install attached F-40 137-207-712-10
plate) F-100 137-207-713-10

3
MD-602, 612
Panel Japanese/ Treadle
type English type
0
1
5
7
3
8
C
External
(HB)
Japanese
English
Japanese
English
D
C
D
Built-in
(BI)
Maximum
rotation speed
0 1000 rpm
1 2000 rpm
3 3000 rpm
4 3500 rpm
5 4000 rpm
6 4500 rpm
7 5000 rpm
8 6000 rpm
9 8000 rpm
A 2200 rpm
B 2400 rpm
C 2600 rpm
D 6500rpm
Panel type
BF panel F panel
0 BF-0 F-0
1 None None
2 BF-20 F-20
3 BF-40 F-40
4 BF-100 F-100
Single/3-phase
0 Single-phase
1 3-phase
Voltage Switch Destination
0 240V SAA compatible part Australia
1 110V Standard part General
2 110V With OCR USA
3 110V SJT Canada
4 230V None Europe
5 220V Standard part General
6 230V Standard part Greece
7 230V Standard part General
8 230V SAA compatible part New Zealand
9 100V Domestic specifications Japan
A 240V Standard part General
B 110V SJT + OCR Canada
C 220V With OCR General
D 220V SJT + OCR Canada
E 220V FOR B883 General
For single-phase
Voltage Switch Destination
0 200V Domestic specifications Japan
1 220V Standard part
2 220V With OCR USA
3 220V With SJT Canada
B 220V With SJT & OCR Canada
For 3-phase
Compatible head
Single needle Twin needle
0 B774 E B842
1 B748A F B872
2 B798/728 G B845/875
3 B722 H B847
4 B724 J B837
5 B201 K B877
6 B791 L B878
7 B737 M P73/P81
8 B852/853/854 N C51
9 B883 P B848
A Overlock
B B772A
C B778A
D B781
3. Model configuration
13760273355
●Japanese / English;
Name Plate, Warning Label
Instruction Manual
●C; With one forward and one
back step
D; With two forward and two
back steps

4MD-602, 612
4. Explanation of the name plate
yproduction
date
A January
B February
C March
D April
E May
F June
G July
H August
J September
K October
L November
M December
emaximum
speed (rpm)
0 1000
1 2000
2 2500
3 3000
4 3500
5 4000
6 4500
7 5000
8 6000
9 8000
A 2200
B 2400
C 2600
D 6500
*phase
0 single
1 three
wPulley size
3 φ 90
4 φ 105
ofactory
9 Kariya
qTreadle type
C One forward and
one back step
D Two forward and
two back step
!0 modification No.
tstandard
0 None
A Australia
ECE
ui year (2 digits)
!1!2!3!4 serial No.
MD-6*2*-*
CONTROL BOX
TYPE B qwert
NO. yuio!0!1!2!3!4
****** PHASE
OUT PUT 400W
VOLTS *********
HERTZ 50/60
FOR MD-60A
MADE IN JAPAN
BROTHER INDUSTRIES, LTD.
MD-60A
AC SERVO MOTOR
NO. yuio!0!1!2!3!4
OUT PUT 400W
R.P.M. 3500
SUPPLIED FROM CONTROL BOX
MD-602/612 MADE IN JAPAN
BROTHER INDUSTRIES, LTD.
Control box name plate
Motor name plate
display
phase voltage phase voltage
single 110V SINGLE 110
single 220V SINGLE 220 230 240
single 230V SINGLE 220 230 240
single 230V CE SINGLE 230
single 240V SINGLE 220 230 240
three 220V THREE 220
rMachine Head Model No.
(Single needle)
0 B774 MD-6*2-1
1 B748A MD-6*2-1
2 B798/728 MD-6*2-1
3 B722 MD-6*2-1
4 B724 MD-6*2-1
5 B201 (B755) MD-6*2-1
6 B791 MD-6*2-1
7 B737 MD-6*2-1
8 B852/853/854 MD-6*2-1
9 B883 MD-6*2-5
A OVERLOCK MD-6*2R-1
B B772A MD-6*2-1
C B778A MD-6*2-1
D B781 MD-6*2-1
rMachine Head Model No.
(Twin needle)
E B842 MD-6*2-1
F B872 MD-6*2-1
G B845/875 MD-6*2-1
E B847 MD-6*2-1
J B837 MD-6*2-1
K B877 MD-6*2-15
L B878 MD-6*2-15
M P73/P81 MD-6*2-9
N C51 MD-6*2-9
P B848 MD-6*2-1

5
MD-602, 612
Hazardousvoltage
will cause injury.
Turn off main
switch and wait 5
minutes before
opening this cover.
Un voltage non adapté
provoquedes blessures.
Eteindrel'interrupteur et
attendre 5 minutes
avantd' ouvrir le capot
Hochspannung
verletzungsgefahr!
Bitte schalten sie den
hauptschalter aus und
warten sie 5 minuten,
bevor sie diese
abdeckung öffnen.
Unvoltaje inadecuado
puede provocar las
heridas.
Apagar el interruptor
principal y esperar 5
minutos antes de abrir
esta cubierta.
5. Installation
Do not use the motor near sources of strong electrical interference. If the motor is installed in a location which
is close to sources of strong electrical interference such as high-frequency welders, it may cause problems with
correct operation of the sewing machine.
Disconnect the power cord plug from the wall outlet before installing the motor.
The motor and control box weigh approximately 13 kg. Take care not to drop them on your feet when installing
them to the work table.
Be sure to tighten the nuts securely.
If they are not tightened properly, it could cause the sewing machine to vibrate or shift its position while sewing.
CAUTION
5.1 Installing the motor to the work table
1. Insert the bolts winto the holes in the work table qand then secure the motor uto the work table qby tightening
the motor mounting brackets eto the work table qwith the flat washers r, spring washers tand nuts yas
shown in the illustration.
2. The positions of the work table qholes are shown in the illustration.
5.2 Attaching the belt
1. Tilt back the machine head and place the belt qonto
the motor pulley wand the machine pulley e.
2. Turn the two nuts rto adjust the deflection in the V-
belt qwhen the center of the belt is pushed.
The recommended values are:
1. For single-needle sewing machines and overlock
machines, the deflection should be 10 – 14 mm when
the belt is pushed with a force of 5 N (500 g).
2. For twin needle sewing machines, the deflection
should be 10 – 20 mm when the belt is pushed with
a force of 10 N (1 kg).
Note:
While using the sewing machine, the belt will conform
to the pulley and cause the belt tension to loosen. If the
belt tension is too loose, the following problems can
occur.
1. The stopping position may shift.
2. An abnormal noise may be heard due to belt slip-
page.
3. The belt may become too loose and contact the
cover.
4. When sewing heavy materials, the belt may slip on
the pulley and the sewing machine may stop.
w
q
e
r
t
y
q
e
u
57 159
66
3-φ8.5
q
e
r
w
10 – 14 mm of deflection
Tilt back

6MD-602, 612
5.5 Adjusting the belt cover safety mechanisms
5.5.1 Adjusting the belt casting prevention guide
1. Loosen the screw q.
2. A mark showing the pulley size is stamped on the belt
cover. (The available inner diameters are 90 mm, 105
mm and 80 mm.)
Adjust the position of the belt casting prevention cover
win accordance with the pulley size. Align the projec-
tion position with the mark. (For 80 mm diameter pul-
leys, install the belt casting prevention cover win the
reverse direction.)
3. After adjusting, tighten the screw q.
Note:
This safety guide will prevent the belt from coming off
even when the machine head is tilted back.
5.5.2 Adjusting the finger guard
1. Loosen the screw e.
2. Install the finger guard so that it is on the belt winding
side.
3. A mark showing the pulley size is stamped on the belt
cover. (The available inner diameters are 80 mm, 90
mm and 105 mm.)
Adjust the position of the finger guard rin accordance
with the pulley size. Align the center of the screw with
the mark.
4. After adjusting, tighten the screw e.
Note:
The finger guard is a safety mechanism that prevents
fingers from being caught in the belt.
Change the position of the finger guard rto match the
direction of rotation of the motor pulley.
e
r
w
q
Forward rotation
Mark for 105 mm-
diameter pulley
Mark for 90 mm-
diameter pulley
Mark for 80 mm-
diameter pulley
Mark for 105 mm-
diameter pulley
Mark for
90 mm-
diameter
pulley
Mark for 80 mm-
diameter pulley
e
r
Reverse rotation (Overlock machines)
q
w
e
w
5.3 Installing the belt cover
1. Secure the belt cover qto the motor ewith the two
screws was shown in the illustration. At this time, po-
sition the belt cover qso that it does not touch the belt.
2. A belt casting prevention guide and finger guide are
provided on the belt cover. Refer to “5.5 Adjusting the
belt cover safety mechanisms” on this page.
5.4 Connecting the connecting rod
•Pass the connecting rod joint qthrough hole A in the
treadle lever w, and tighten it with the spring washer
eand nut r.
•Adjust the position of the machine treadle plate so that
the connecting rod is perpendicular to the treadle plate.
Note:
The treadle pressure is adjusted to the position of hole
A at the time of shipment from the factory. Refer to “6.
Adjusting the treadle unit”.
q
e
r
w
A

7
MD-602, 612
Hazardous voltage
will cause injury.
Turn off main
switch and wait 5
minutes before
opening this cover.
Un voltage non adapté
provoque des blessures.
Eteindrel'interrupteur et
attendre 5 minutes
avantd' ouvrir le capot
Hochspannung
verletzungsgefahr!
Bitte schalten sie den
hauptschalter aus und
warten sie 5 minuten,
bevor sie diese
abdeckung öffnen.
Un voltaje inadecuado
puede provocar las
heridas.
Apagar el interruptor
principal y esperar 5
minutos antes de abrir
esta cubierta.
5.6 Connecting the cords
Turn off the power switch and wait for the power indicator on the panel display to turn off before connecting
and disconnecting any of the connectors.
Turn off the power switch before inserting or removing the AC power cord plug.
Be sure to connect the power supply to a secure ground. If the ground is not securely connected, electric shocks
may result.
CAUTION
5.6.2 Connecting the sewing machine and control box
6-pin plug
Synchronizer cord
12-pin plug
5.6.1 Connecting the power cord, power switch and ground cord
Power switch
Power cord
Ground
Green/yellow
Sewing machine oil pan Ground cord
Mounting bracket
grounding screw
Ground symbol
•Loosen the two screws q, and then gently pull the
cover wtoward you to open it.
•Connect the 12-pin plug and the 6-pin plug.
•Close the cover w(be careful not to clamp the cord)
and tighten the two screws q.
•Connect the synchronizer cord e.
e
Hazardous voltage
will cause injury.
Turn off main
switch and wait 5
minutes before
opening this cover.
Un voltage non adapté
provoque des blessures.
Eteindrel'interrupteur et
attendre 5 minutes
avantd' ouvrir le capot
Hochspannung
verletzungsgefahr!
Bitte schalten sie den
hauptschalter aus und
warten sie 5 minuten,
bevor sie diese
abdeckung öffnen.
Un voltaje inadecuado
puede provocar las
heridas.
Apagar el interruptor
principal y esperar 5
minutos antes de abrir
esta cubierta.
q
e
w

8MD-602, 612
Note:
The puller output is output from the option output during machine operation with the
settings made at shipment from the factory.
Note the following points when connecting to the option output terminals.
a. Connect a solenoid or air valve with a resistance of 10 Ωor greater.
b. The voltage between the terminals should be equivalent to 40 V DC. When con-
necting an air valve, connect a resistor in series so that the rated voltage is ob-
tained.
c. Never short circuit the output terminals.
Note:
If using an automatic presser foot lifter, set the DIP switch SW1-3 on the circuit board to ON. (Refer to “7.5.2 Other DIP
switch functions”.)
For machine solenoid
For standing pedal (option) For synchronizer
For presser foot lifter
12-pin plug
6-pin plug
12-pin plug No.
Thread trimming solenoid r·t
Thread wiping solenoid u·i
Quick reverse solenoid !0·!1
Quick reverse switch o·!2
Option output q·w
Ground e
Spare y
•12-pin plug terminal 6-pin plug No.
Presser lifter solenoid q·r
40 V power supply e
Knee switch w·t
Ground y
•6-pin plug terminal
9-pin plug 9-pin plug No.
High-speed switch w
Low-speed switch y
Thread trimming switch e
Presser foot lift switch u
+8 V q
VSP i
0 V r
Ground o
Spare t
•9-pin plug terminal 8-pin plug No.
Ground q
+5 V w
Needle down signal e
0 V r
NONP t
Needle up signal y
Encoder u
Ground i
•8-pin plug terminal
Approx.
40 V
Resistor
Air valve

9
MD-602, 612
5.7 Installing the head lamp
Use a lamp which is rated at 6 V AC and 20 W or less as the head lamp.
If a lamp with a higher rating than this is used, it could cause the lamp wires and the transformer to overheat
and burn out.
1. Open the control box cover q.
2. Loosen the screws eof the terminal block w, insert the
lamp cords tinto the clamps ras far as they will go,
and then tighten the screws e.
Note:
Do not tighten the screws etoo tightly, as this may
damage the terminal block w.
3. Pass the lamp cords tthrough the rubber plug y.
Refer to the illustration of the rubber plug yin “5.8
Connecting the external operation panel”at below-left
on this page at this time.
4. Close the control box cover q.
5.8 Connecting the external operation panel
1. The F-20, F-40 and F-100 operation panels can be used.
2. Disconnect the synchronizer cord q.
3. Loosen the screw w, and then gently pull the cover e
toward you to open it.
4. After opening the pawl of the circuit board connector
r, align the ▼mark on the operation panel connector
twith the ▼mark on the circuit board connector r,
and securely insert operation panel connector tuntil
the pawl locks.
5. Fit the rubber plug yonto the operation panel cord u
as shown in the illustration, and then install the con-
trol box while being careful not to damage the cord u.
(Break the membrane of the rubber plug y.)
6. Close the cover eand secure it with the screw w. Be
careful not to clamp any of the cords with the cover.
7. Connect the synchronizer cord q.
Note:
When an external operation panel is installed, the backtacking function of the control circuit board will be disabled,
so use the external operation panel to carry out backtacking.
CPU
uy
e
w
q
r
t
CAUTION
Lamp cords
y
w
t
q
e
t
r
For lamp cords
For external
operation panel
For option
Lamp

10 MD-602, 612
q
w
e
Thread trimming
r
6. Adjusting the treadle unit
6.1 Operating the treadle
•There are two types of treadles, one with one forward and one rear stage and one with two forward and two rear
stages. These are provided according to the destination of the machine.
6.1.1 For treadles with one forward and one rear stage
High speed
Neutral
Low speed
1. The treadle is at the neutral position qwhen the treadle is not pressed.
2. When the treadle is gently depressed to position w, low-speed sewing is carried out. If it is then depressed as far as
e, high-speed sewing is carried out.
3. When the treadle is pressed forward and then back to the neutral position q, the needle will stop below the needle
plate (when needle down stop mode has been set).
4. When the treadle is depressed backwards to position r(or when the treadle is pressed backward to position rand
is then returned to neutral position q), the thread trimmer operates, and then the needle will be raised and stop
above the needle plate.
5. If using with the synchronizer cord disconnected
•When the treadle is pressed forward and then back to the neutral position q, the machine will stop regardless of
the needle position.
•Thread trimming will not be carried out even if the treadle is pressed backed to position r. (The sewing machine
does not operate.)
6. If an automatic presser foot lifter is being used
•The presser foot will rise when the treadle is pressed backwards. If the knee switch is pressed, the pressure foot will
not raise with the treadle operation, so raise and lower the presser foot with the knee switch.
•When the treadle is pressed backwards and the thread is trimmed, the sewing machine will stop, and the presser
foot will rise. To lower the presser foot, press the treadle backwards and then return it to the neutral position q. The
presser foot can also be lowered using the knee switch. If the treadle is pressed forward, the sewing machine will
operate after the presser foot lowers.
Note:
The presser foot can be raised and lowered by returning the treadle only from when the power switch is turned on to
when the knee switch is operated.
Take your foot off the treadle before turning on the power switch.
CAUTION

11
MD-602, 612
Take your foot off the treadle before turning on the power switch.
CAUTION
6.1.2 For treadles with two forward and two rear stages
1. The treadle is at the neutral position qwhen the treadle is not pressed.
2. When the treadle is gently depressed to position w, low-speed sewing is carried out. If it is then depressed as far as
e, high-speed sewing is carried out.
3. When the treadle is pressed forward and then back to the neutral position q, the needle will stop below the needle
plate (when needle down stop mode has been set).
4. When the treadle is depressed backwards to position r(or when the treadle is pressed backward to position rand
is then returned to neutral position q), the thread trimmer operates, and then the needle will be raised and stop
above the needle plate.
5. If using with the synchronizer cord disconnected
•When the needle is pressed forward and then back to the neutral position q, the machine will stop regardless of
the needle position.
•Thread trimming will not be carried out even if the treadle is pressed backed to position r. (The sewing machine
does not operate.)
6. If an automatic presser foot lifter is being used
•The presser foot will rise when the treadle is gently pressed back to the backward position t.
•The presser foot will lower when the treadle is returned to the neutral position q.
•The presser foot will lower if the treadle is gently pressed to the position ywhile the presser foot is raised.
Low speed
q
y
w
e
t
r
Presser foot raised
Thread trimming
Neutral
Presser foot lowered
High speed

12 MD-602, 612
abc
e
q
r
y
w
6.3 When using the automatic presser foot lifter
device
1. When the treadle is depressed to position r, the
presser foot is raised.
2. If you would like the treadle pressure to be lighter when
it is depressed forward from the 2nd step to the 1st
step, change the position of the spring from Fto E.
If you would like the pedal return to be from the 2nd
step to the 1st step at this time, change the spring po-
sition from Cto D.
•When changing the spring positions from Fto Eand
from Cto D, you must remove the three screws qof
the treadle unit and disconnect the treadle unit from the
control box before changing the spring positions.
A
B
6.2.1 Adjusting the treadle pressure
•If the machine starts running at a low speed when your
foot is simply resting on the treadle, or if the treadle
pressure is too weak, adjust the position (a to c) at
which the treadle spring qis hooked onto the treadle
lever w.
Note:
The treadle pressure will increase from position a to po-
sition c.
6.2.2 Adjusting the treadle return pressure
•Loosen the nut eand turn the bolt r. The treadle re-
turn pressure becomes heavier as the bolt ris tight-
ened, and becomes lighter as the bolt ris loosened.
6.2 Adjusting the treadle
Turn off the power switch before starting work, otherwise the motor may operate, which could result in injury.
CAUTION
Fig A Fig B
6.2.3 Adjusting the treadle stroke
•Remove the nut t, and then move the connecting rod joint yfrom the position in figure A to the position in figure
B. The treadle stroke will increase by approx. 1.25 times.
Note:
This adjustment will also affect the treadle pressure and the treadle return pressure, so these settings should be
readjusted if necessary.
t
q
w
r
q
q
CD
F
E
Treadle unit

13
MD-602, 612
MD-602-1
CONTROL BOX
TYPE BC4670
NO. B019A1101
SINGLE PHASE
OUTPUT 400 W
VOLTS
220 230 240
HERTZ 50/60
FOR MD-60A
MADE IN JAPAN
BROTHER INDUSTRIES, LTD.
7. Using the control box
7.1 Before turning on the power switch
Control box rating plate (Example: Single-phase 220 V
specifications)
q
w
e
Model
Power
supply
phase
Power
supply
voltage
•Check the power supply and the control box specifica-
tions.
1. Model q
MD-602 (for single-phase power supply)
MD-612 (for three-phase power supply)
The model should match the power supply phase w.
2. The power supply voltage eindicated is an AC volt-
age.
3. The power supply frequency can be either 50 Hz or 60
Hz.
Speed adjustment knob
7.2 Power switch and power indicator
•When the power ON switch qis pressed, the power
indicator (green) elights and the power turns on.
•When the power OFF switch wis pressed, the power
indicator (green) eturns off and the power switches
off.
7.3 Setting the sewing speed
•Turn the speed adjustment knob ron the front of the
control box clockwise to increase the sewing machine
speed (the speed corresponding to the treadle depres-
sion amount), and turn it counterclockwise to reduce
the speed.
•The maximum sewing speed that can be set is the sew-
ing speed which is determined by DIP switch settings.
Refer to “7.5.2.1 DIP switch 1 functions”. The minimum
sewing speed is the sewing speed when the treadle is
at the low-speed sewing position.
1. Are all connectors connected correctly?
•Synchronizer connector
•Sewing machine connector
•Ground cord
Refer to “5.6 Connecting the cords”.
2. Is the sewing machine cord touching the V-belt?
Is the belt tension correct? Refer to “5.1 Installing the motor to the work table”and “5.2 Attaching the belt”.
3. Does the sewing machine operate when turned gen-
tly by hand?
qw
rePower indicator
Confirm that the power supply matches the motor and the control box specifications before turning on the
power switch. The motor, control box or sewing machine could be damaged if the supply voltage is too high.
CAUTION

14 MD-602, 612
Hazardous voltage
will cause injury.
Turn off main
switch and wait 5
minutes before
opening this cover.
Un voltage non adapté
provoque des blessures.
Eteindrel'interrupteur et
attendre 5 minutes
avantd' ouvrir le capot
Hochspannung
verletzungsgefahr!
Bitte schalten sie den
hauptschalter aus und
warten sie 5 minuten,
bevor sie diese
abdeckung öffnen.
Un voltaje inadecuado
puede provocar las
heridas.
Apagar el interruptor
principal y esperar 5
minutos antes de abrir
esta cubierta.
7.4 Control box DIP switch setting procedure
Do not clamp the cords inside the control box when closing the control box cover.
CAUTION
•Make sure that the DIP switches are set correctly, otherwise incorrect operation may result.
•Disconnect the synchronizer cord q.
•Loosen the two screws w, and then gently pull the
cover etoward you to open it.
•Set the DIP switches.
Refer to the tables for details of DIP switch functions.
•Close the cover e(be careful not to clamp the cord)
and tighten the two screws w.
•Connect the synchronizer cord q.
w
q
e
Wait at least 5 minutes after turning off the power switch before opening the cover of the control box. Touching
areas where high voltages are present can result in severe injury.
WARNING