Brother SN-7220 Instruction manual

S-7220B
INSTRUCTION MANUAL
Please read this manual before using the machine.
Please keep this manual within easy reach for quick reference.
SINGLE NEEDLE DIRECT DRIVE NEEDLE FEED LOCK STITCHER
WITH THREAD TRIMMER
Thank you very much for buying a BROTHER sewing machine. Before using your new machine,
please read the safety instructions 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, 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.
S-7220B
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
DANGER
The instructions which follow this term indicate situations where failure to follow the
instructions may result in death or serious injury.
CAUTION
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.
Symbols
·····
This symbol (
) indicates something that you should be careful of. The picture inside the triangle
indicates the nature of the caution that must be taken.
(For example, the symbol at left means “beware of injury”.)
·····
This symbol (
·····
This symbol (
) indicates something that you must do. The picture inside the circle indicates the
nature of the thing that must be done.
(For example, the symbol at left means “you must make the ground connection”.)
) indicates something that you must not do.
S-7220B
i
[2] Notes on safety
DANGER
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.
CAUTION
Environmental requirements
Use the sewing machine in an area which is free
from sources of strong electrical noise such as
electrical line noise or static electric noise.
Sources of strong electrical noise may cause
problems with correct operation.
Any fluctuations in the power supply voltage
should be within r10% 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 power
consumption.
Insufficient power supply capacity may cause
problems with correct operation.
The ambient temperature should be within the
range of 5qC to 35qC 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.
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.
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 approximately 46 kg.
The installation should be carried out by two or
more people.
Do not connent the power cord until installation is
complete. The machine may operate if the treadle
is depressed by mistake, which could result in
injury.
Turn off the power switch before inserting or
removing the plug, otherwise damage to the
control box could result.
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.
ii
S-7220B
When securing the cords, do not bend the cords
excessively or fasten them too hard with staples,
otherwise there is the danger that fire or electric
shocks could occur.
If using a work table which has casters, the casters
should be secured in such a way so that they
cannot move.
Use both hands to hold the machine head when
tilting it back or returning it to its original position. If
only one hand is used, the weight of the machine
head may cause your hand to slip, and your hand
may get caught.
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 diarrhea.
Keep the oil out of the reach of children.
CAUTION
Sewing
This sewing machine should only be used by
operators who have received the necessary training
in safe use beforehand.
Attach all safety devices before using the sewing
machine. If the machine is used without these
devices attached, injury may result.
The sewing machine should not be used for any
applications other than sewing.
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.
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.
Turn off the power switch at the following times.
The machine may operate if the treadle is
depressed by mistake, which could result in injury.
yWhen threading the needle
yWhen replacing the bobbin and needle
yWhen not using the machine and when leaving
the machine unattended
If using a work table which has casters, the casters
should be secured in such a way so that they
cannot move.
Use both hands to hold the machine head when
tilting it back or returning it to its original position. If
only one hand is used, the weight of the machine
head may cause your hand to slip, and your hand
may get caught.
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.
Cleaning
Turn off the power switch before carrying out
cleaning. The machine may operate if the treadle is
depressed by mistake, which could result in injury.
Use both hands to hold the machine head when
tilting it back or returning it to its original position. If
only one hand is used, the weight of the machine
head may cause your hand to slip, and your hand
may get caught.
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 diarrhea.
Keep the oil out of the reach of children.
Use only the proper replacement parts as specified
by Brother.
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.
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 treadle is
depressed by mistake, which could result in injury.
yWhen carrying out inspection, adjustment and
maintenance
yWhen 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.
S-7220B
Use both hands to hold the machine head when
tilting it back or returning it to its original position.
If only one hand is used, the weight of the machine
head may cause your hand to slip, and your hand
may get caught.
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.
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
2
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
Safety devices:
(A) Finger guard
(B) Thread take-up cover
Oil pan
Control box
3722M
iv
S-7220B
CONTENTS
1. NAMES OF MAJOR PARTS................ 1
2. MACHINE SPECIFICATIONS .............. 2
3. INSTALLATION.................................... 3
3-1. Table processing diagram ................................ 4
3-2. Installation ........................................................ 4
3-3. Lubrication........................................................ 8
3-4. Connecting the cords ....................................... 9
3-4-1. Opening the control box cover............. 9
3-4-2. Connecting the cords .......................... 9
3-5. Test operation (Operating the treadle) ............. 12
4. PREPARATION BEFORE SEWING .... 13
4-1. Installing the needle ......................................... 13
4-2. Removing the bobbin case............................... 13
4-3. Winding the lower thread ................................. 14
4-4. Installing the bobbin case................................. 14
4-5. Threading the upper thread.............................. 15
4-6. Adjusting the stitch length ................................ 15
4-7. Using the thread wiper ..................................... 16
4-8. Using the knee lifter ......................................... 16
5. USING THE OPERATION PANEL
(BASIC OPERATIONS) ....................... 17
5-1. Names and functions ....................................... 17
5-2. Sewing start and end backtack stitches ........... 19
5-3. Sewing continuous backtack stitches............... 20
5-4. Sewing fixed stitches........................................ 21
5-5. Sewing name labels ......................................... 22
5-6. Sewing pleat presser stitches .......................... 23
5-7. Using the lower thread counter ........................ 24
6. USING THE OPERATION PANEL
(ADVANCED OPERATIONS).............. 25
6-1. Names and functions ....................................... 25
6-2. Adjusting the needle up stop position............... 26
6-3. LOCK key......................................................... 26
6-4. Resetting all settings to their defaults............... 26
7. USING THE CONTROL BOX PANEL
(BASIC OPERATIONS) ....................... 27
7-1. Names and functions ....................................... 27
7-2. Sewing start and end backtacking and
continuous backtacking and locking thread
trimming ........................................................... 28
8. USING THE CONTROL BOX PANEL
(ADVANCED OPERATIONS).............. 32
8-1. Before setting any functions .............................32
8-2. Changing the needle stop position ...................32
8-3. Slow start..........................................................33
8-4. Correction sewing .............................................33
8-5. Initialization method ..........................................33
8-6. Setting the needle up stop position and
needle down stop position ................................34
9. SEWING ............................................... 35
9-1. Sewing..............................................................35
9-2. Backtacking ......................................................35
9-3. Sewing condensed stitches ..............................36
10. THREAD TENSION ............................ 37
10-1. Adjusting the thread tension ...........................37
10-2. Adjusting the presser foot pressure ................38
10-3. Adjusting the trailing length after thread
trimming..........................................................38
11. CLEANING ......................................... 39
11-1. Daily cleaning procedures ..............................39
11-2. Applying grease [When “GrEASEUP”
appears… when using the operation panel] ...42
11-3. Applying grease [When “GU” appears ...
when using the control box panel] ..................44
12. ADJUSTING THE ROTARY HOOK
LUBRICATION AMOUNT .................. 46
13. STANDARD ADJUSTMENTS............ 47
13-1. Adjusting the actuator position........................47
13-2. Adjusting the safety switch position ................48
13-3. Adjusting the thread take-up spring ................49
13-4. Adjusting arm thread guide R .........................50
13-5. Adjusting the presser foot height ....................50
13-6. Adjusting of the feed dog height .....................51
13-7. Adjusting the feed dog angle ..........................52
13-8. Adjusting the needle bar height ......................53
13-9. Adjusting the needle and
feed mechanism timing...................................54
13-10. Adjusting the needle and rotary hook
timing ............................................................55
13-11. Adjusting the treadle .....................................56
13-12. Adjusting the presser foot floating amount
(minute lifting amount) ..................................56
14. TROUBLESHOOTING ....................... 57
14-1. Sewing............................................................57
14-2. Error code displays .........................................62
S-7220B
1. NAMES OF MAJOR PARTS
1. NAMES OF MAJOR PARTS
3723M
(1)
(3)
(5)
(7)
(9)
(11)
(13)
(15)
Bobbin winder
Lifting lever
Presser foot
Control box panel
Power switch
Reverse lever
Machine pulley
Cotton stand
Safety devices
(16) Thread take-up cover
1
(2)
(4)
(6)
(8)
(10)
(12)
(14)
Thread wiper
Quick reverse (Actuator)
Control box
Knee lifter assembly
Oil gauge window
Stitch length dial
Operation panel (Models with operation panel)
(17)
Finger guard
S-7220B
2. MACHINE SPECIFICATIONS
2. MACHINE SPECIFICATIONS
4
O
O
Quick reverse
Thread wiper
Lubrication type
Use
Max. sewing speed
Start backtacking and continuous backtacking speed
End backtacking speed
Max. stitch length
Lifting lever
Presser foot
height
Knee lifter
Feed dog height
Needle (DBu1, DPu5)
Motor
Control circuit
0
Minimum lubrication
3
Semi dry
3
For medium-weight
materials
5
For heavy-weight materials
-403
1
5,000 rpm*
-433
-405
2
4,000 rpm
4,000 rpm*
220 - 3,000 rpm
1,800 rpm
4.5 mm
5.5 mm
6 mm
16 mm
1.0 mm
1.2 mm
#11 - #18
#19 - #22
AC servo motor (4-pole, 450W)
Microprocessor
*1…When sewing at speeds of 4,000 rpm or higher, set the stitch length to 3.5 mm or less.
*2…When sewing at speeds of 3,000 rpm or higher, set the stitch length to 4.5 mm or less.
Rotary hook
-403, -433
Lubricated /
for medium materials
-405
Lubricated /
for heavy materials
Lubricating oil
-403, -405
Rotary hook
Needle bar
High-speed spindle
S-7220B
-433
High-speed spindle
Special Brother grease
2
3. INSTALLATION
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 weighs approximately 46 kg.
The installation should be carried out by two or more
people.
Do not connect the power cord until installation is
complete. The machine may operate if the treadle is
depressed by mistake, which could result in injury.
Use both hands to hold the machine head when
tilting it back or returning it to its original position. If
only one hand is used, the weight of the machine
head may cause your hand to slip, and your hand
may get caught.
About the machine set-up location
yDo not set up this sewing machine near other equipment such as
televisions, radios or cordless telephones, otherwise such
equipment may be affected by electronic interference from the
sewing machine.
yThe sewing machine should be plugged directly into an AC wall
outlet. Operation problems may result if extension cords are
used.
2086M
Carrying the machine
yThe machine should be carried by the arm by two people as
shown in the illustration.
* Hold the motor cover (A) by hand also so that the pulley does
not rotate.
3631M
Tilting back the machine head
yHold section (B) with your foot so that the table does not move,
and then push the arm with both hands to tilt back the machine
head.
2088M
Returning the machine head to the upright position
1. Clear away any tools, etc. which may be near the table holes.
2. While holding the face plate with your left hand, gently return the
machine head to the upright position with your right hand.
2089M
3
S-7220B
3. INSTALLATION
3-1. Table processing diagram
yThe top of the table should be 40 mm in thickness and should be strong enough to hold the weight and with-stand the
vibration of the sewing machine.
yDrill holes as indicated in the illustration below.
Cotton stand hole
Cord hole
Head rest hole
Control box mounting hole
2090M
3-2. Installation
1. Control box
(1)
(2)
(3)
(4)
(5)
Control box
Bolts [3 pcs]
Nuts [3 pcs]
Spring washers [3 pcs]
Washers [3 pcs]
2. Connecting rod
(6) Connecting rod
(7) Nut
2091M
S-7220B
4
3. INSTALLATION
3. Power switch
(1) Power switch
(2) Screws [2 pcs]
Operator
2092M
4. Oil pan
(1) Head cushions (left) [2 pcs]
(2) Head cushions (right) [2 pcs]
(3) Oil pan
3632M
5. Rubber cushions
(1) Rubber cushions [2 pcs]
(2) Nails [4 pcs]
6. Knee lifter complying bar
(3) Knee lifter complying bar
2094M
5
S-7220B
3. INSTALLATION
7. Machine head
(1) Hinges [2 pcs]
(2) Machine head
(3) Head rest
NOTE:
Tap the head rest (3) securely into
the table hole. If the head rest (3) is
not pushed in as far as it will go, the
machine head will not be sufficiently
stable when it is tilted back.
3724M
8. Operation panel
(1) Rubber cushion
(Remove the seal (2), and then
attach the rubber cushion (1) to the
panel setting plate (3).)
(4)
(5)
(6)
(7)
Operation panel
Washers [2 pcs.]
Spring washers [2 pcs.]
Screws [2 pcs.]
(The washers (5), spring washers
(6) and screws (7) are used to
secure the side plate)
3725M
9. Sticker (Remove)
(1) Sticker
2097M
S-7220B
6
3. INSTALLATION
10. Cotton stand
(1) Cotton stand
NOTE:
Securely tighten the nut (4) so that
the two rubber cushions (2) and the
washer (3) are securely clamped and
so that the cotton stand (1) does not
move.
3636M
11. Knee lifter plate
(1) Knee lifter plate
(2) Bolt
* Loosen the bolt (3) and move the
knee lifter plate (1) to a position
where it is easy to use.
3637M
<Knee lifter adjustment>
1. Turn the machine pulley so that the feed dog is below the
top of the needle plate.
2. Lower the presser foot (5) by using the lifting lever (4).
3726M
3781M
3. Loosen the nut (6).
4. Turn the screw (8) to adjust so that the amount of play in
the knee lifter (7) is approximately 2 mm when the knee
lifter plate (1) is gently pressed.
5. Securely tighten the nut (6).
<Adjusting the height of the presser foot>
The height of the presser foot can be adjusted to a maximum
of 16 mm.
1. Loosen the nut (9).
2. Turn the adjusting screw (10) to adjust so that the presser
foot (5) is at the desired position within a distance of 16
mm of the needle plate when the knee lifter plate (1) is
fully pressed.
3. After adjustment is completed, securely tighten the nut
(9).
Within 16 mm
3727M
7
S-7220B
3. INSTALLATION
3-3. Lubrication
CAUTION
Do not connect the power cord until lubrication has been completed, otherwise the machine may operate if the
treadle is depressed by mistake, which could result in injury.
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
diarrhea.
Keep the oil out of the reach of children.
When cutting the nozzle of the oil tank, hold the base of the nozzle securely.
If you hold the end of the nozzle, injury from the scissors may result.
3640M
yThe sewing machine should always be lubricated and the
oil supply replenished before it is used for the first time,
and also after long periods of non-use.
yUse only the lubricating oil (Nisseki Mitsubishi Sewing
Lube 10N; VG10) specified by Brother.
* If this type of lubricating oil is difficult to obtain, the
recommended oil to use is <Exxon Mobil Essotex SM10;
VG10>.
1. Hold the base of the nozzle on the accessory oil tank (1),
and then use scissors to cut 3 - 5 mm off the end of the
nozzle.
2. Tilt back the machine head.
3. Remove the rubber cap (2), and pour 120ml of lubricating
oil into the oil tank (3).
(Use the upper reference line (4) as a guide when
pouring.)
4. Replace the rubber cap (1).
5. Return the machine head to its original position.
6. Check that the oil gauge (6) comes to the upper reference
line in the oil gauge window (5).
<Lubrication oil replenishment interval>
If the oil gauge (6) drops below the lower reference line (or if
the oil level drops below the lower reference line (7) on the oil
tank (3)), be sure to replenish the oil.
Upper reference
line
Lower reference
line
3728M
S-7220B
8
3. INSTALLATION
3-4. Connecting the cords
DANGER
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.
CAUTION
Contact your Brother dealer or a qualified electrician for any electrical work that may need to be done.
Do not connect the power cord until all cords have been connected.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
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.
3-4-1. Opening the control box cover
(1) Screw
(2) Cover
3642M
3-4-2. Connecting the cords
1. Sewing machine cords
3729M
9
S-7220B
3. INSTALLATION
(1) 7-pin head detector unit connector
(2) 10-pin operating panel connector
(Models with operation panel)
(3) 14-pin encoder connector
(4) 14-pin machine connector
Refer to the following page for the 4-pin
motor connector.
Push in securely until
the tabs (5) engage.
3131M
3132M
2. Binding the cords
(1) Repeat cable tie
(2) Wire clip
<Removal>
NOTE:
yBind the cords in such a way that the
connector does not get pulled out.
yAll cords that come out from the
control box should be secured to the
cord holder (3) using the repeat
cable tie (1), otherwise vibration from
the sewing machine may cause the
cords to become disconnected,
which can cause problems with the
operation of the control box.
Press
the tab.
<Securing>
Cords
<Closing the cover>
3645M
S-7220B
10
3. INSTALLATION
2111M
3. Other cords
(1)
(2)
(3)
(4)
6-pin power supply connector
4-pin motor connector
Wire clip
Power cord
<For single-phase specifications>
Insert the power cord plug (5) into a
wall outlet.
<For three-phase specifications>
1. Attach an appropriate plug to the
power cord (4). (The green and
yellow wire is the ground wire.)
2. Insert
the
plug
into
a
properly-grounded AC power supply.
<Single-phase>
NOTE:
Do not use extension cords,
otherwise
machine
operation
problems may result.
<Three-phase>
Green and yellow wire
(ground wire)
2112M
4. Ground wire
Ground symbol
(1) Ground wire
(2) Screw [With washer]
(3) Screw
Oil pan
2113M
11
S-7220B
3. INSTALLATION
3-5. Test operation (Operating the treadle)
CAUTION
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.
2114M
1. Turning on the power
<Models with operation panel>
Press the ON power switch (1).
The power indicators (2) and (3) will illuminate.
NOTE: When turning the power switch on for the first
time
The treadle and the operation panel will not operate for
approximately four seconds after the power switch is
turned on.
After approximately 4 seconds, “iniT rPM” (speed
initialization) or “iniT ALL” (full initialization) will be
displayed on the operation panel. After “iniT rPM” or “iniT
ALL” is displayed, the treadle can be operated. (The
operation panel will change to the stitch number display.)
This message will not appear the second and subsequent
times that the power switch is turned on.
3730M
<Models without operation panel>
Press the ON power switch (1).
The power indicators (3) and (4) will illuminate.
NOTE: When turning the power switch on for the first
time
The treadle and control box panel cannot be operated for
approximately 4 seconds after the power switch has been
turned on.
After approximately 4 seconds, “Ar (All reset)” may
appear in the stitch number display (5).
If this happens, turn the power switch off and then back
on again. After that, normal treadle operation will then be
possible.
3647M
2. Test operation
3648M
1. Check that the machine sews at low speed when the
treadle (1) is gently pressed to position (B).
2. Then check that it sews at high speed when the treadle
(1) is gently pressed to position (C).
3. After pressing the treadle (1) forward, check that the
needle is lowered to the top of the needle plate when the
treadle (1) is returned to the neutral position (A). (when
needle down stopping has been set.)
4. If the treadle (1) is pressed to position (D), thread
trimming is carried out and the needle then rises above
the needle plate and stops.
2117M
S-7220B
12
4. PREPARATION BEFORE SEWING
4. PREPARATION BEFORE SEWING
4-1. Installing the needle
CAUTION
Turn off the power switch before installing the needle.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
Front
1. Turn the machine pulley to move the needle bar to its
highest position.
2. Loosen the screw (1).
3. Insert the needle (2) in a straight line as far as it will go,
making sure that the long groove on the needle is at the
left, and then securely tighten the screw (1).
Long
groove
3731M
3732M
4-2. Removing the bobbin case
CAUTION
Turn off the power switch before removing the bobbin case.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
3733M
1. Turn the machine pulley to raise the needle until it is
above the needle plate.
2. Pull the latch (1) of the bobbin case upward and then
remove the bobbin case.
3. The bobbin (2) will come out when the latch (1) is
released.
* There is an anti-spin spring (3) inside the bobbin case.
The anti-spin spring (3) prevents the bobbin from racing at
times such as during thread trimming.
* Use bobbins (2) made of light alloy as specified by
BROTHER.
3734M
For thick materials
0798M
13
2121M
S-7220B
4. PREPARATION BEFORE SEWING
4-3. Winding the lower thread
CAUTION
Do not touch any of the moving parts or press any objects against the machine while winding the lower thread, as
this may result in personal injury or damage to the machine.
1. Turn on the power switch.
2. Place the bobbin (1) onto the bobbin winder shaft (2).
3. Wind the thread several times around the bobbin (1) in the
direction indicated by the arrow.
4. Push the bobbin presser arm (3) toward the bobbin(1).
5. Raise the presser foot with the lifting lever.
6. Depress the treadle. Lower thread winding will then start.
7. Once winding of the lower thread is completed, the bobbin
presser arm (3) will return automatically.
8. After the thread has been wound on, remove the bobbin
and cut the thread with the knife (4).
3735M
* Loosen the screw (5) and move the bobbin presser (6) to
adjust the amount of thread wound onto the bobbin.
More thread
NOTE:
The amount of thread wound onto the bobbin should
be a maximum of 80 % of the bobbin capacity.
Less thread
2123M
2124M
4-4. Installing the bobbin case
CAUTION
Turn off the power switch before installing the bobbin case.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
0802M
2125M
1. Turn the machine pulley to raise the needle until it is
above the needle plate.
2. While holding the bobbin so that the thread winds to the
right, insert the bobbin into the bobbin case.
3. Pass the thread through the slot (1) and under the tension
spring (2), and then pull it out from the thread guide (3).
4. Check that the bobbin turns clockwise when the thread is
pulled.
5. Hold the latch (4) on the bobbin case and insert the
bobbin case into the rotary hook.
3736M
S-7220B
14
4. PREPARATION BEFORE SEWING
4-5. Threading the upper thread
CAUTION
Turn off the power switch before threading the upper thread.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
Turn the machine pulley and raise the thread take-up (1)
before threading the upper thread.
This will make threading easier and it will prevent the thread
from coming out at the sewing start.
3737M
4-6. Adjusting the stitch length
1. Push the dial lock lever (1) up until it clicks to release the
lock.
2. Turn the stitch length dial (2) clockwise or counterclockwise so that the desired stitch length is at the uppermost position on the dial.
yThe larger the number, the longer the stitch length will
be.
(The numbers on the dial are for use as a guide. The
length of the finished stitches may vary depending on
the type and thickness of material being sewn. Adjust
while looking at the finished stitches.)
yWhen turning the stitch length dial (2) from a larger
setting to a smaller setting, it will be easier to turn the
dial if the reverse lever (3) is pushed to the halfwaydown position.
3. Push the dial lock lever (1) down firmly to lock it.
Unlocked
Locked
* Check that the stitch length dial (2) does not rotate.
3738M
15
S-7220B
4. PREPARATION BEFORE SEWING
4-7. Using the thread wiper
Press the thread wiper switch (1) to the
side. If this is
done, the thread wiper (2) will operate after the thread is
trimmed.
2129M
2209M
3739M
4-8. Using the knee lifter
The presser foot (2) can be raised by pressing the knee lifter
plate (1).
2131M
3740M
S-7220B
16
5. USING THE OPERATION PANEL (BASIC OPERATIONS)
5. USING THE OPERATION PANEL
(BASIC OPERATIONS)
5-1. Names and functions
x The operation panel keys cannot be operated while sewing is in progress.
Select the keys and set the number of stitches before starting sewing.
x In the case of keys with indicators, the indicator illuminates when that function is operating, and the indicator switches off
when the key is pressed once more.
Power indicator
2135M
The power indicator illuminates when the power switch is turned on.
(1) Main display
x In start backtack display, AB illuminates and the number of stitches for A and B are
displayed.
x In end backtack display, CD illuminates and the number of stitches for C and D are
displayed.
x In continuous backtack display, ABCD illuminates and the number of stitches for A, B, C
and D are displayed.
x In fixed stitch display, E or F illuminates and the number of stitches for E or F are
displayed.
2136M
(2)
Setting keys
These keys are used to set the number of backtack stitches for A, B, C and D and the
number of fixed stitches for E and F.
x When the
key is pressed, the setting increases from 0 up to 99.
x When the
key is pressed, the setting decreases from 99 down to 0.
2137M
(3)
2138M
2139M
Start backtack key
When this key is pressed so that the indicator illuminates, the number of start backtack
stitches (099) in the A and B stitch number displays is sewn.
2140M
(4)
End backtack key
When this key is pressed so that the indicator illuminates, the number of end backtack
stitches (099) in the C and D stitch number displays is sewn. When the treadle is
depressed backward, the end backtack stitches are sewn and then the thread is trimmed
automatically.
If the treadle has not yet been depressed backward, the end backtack function can be set
to ON, the number of stitches can be changed and the function can be set back to OFF.
2141M
(5)
17
Continuous backtack key
When this key is pressed so that the indicator illuminates, the number of backtack stitches
(099) in the A, B, C and D stitch number displays is sewn continuously. After the sewing
machine sews a full cycle of stitches set by A, B, C and D, the thread is trimmed
automatically.
2142M
S-7220B
5. USING THE OPERATION PANEL (BASIC OPERATIONS)
(6)
Fixed stitch key
When this key is pressed so that the indicator illuminates, the number of stitches (1-1999)
in the E stitch number display is sewn, and then the sewing machine stops automatically.
2143M
(7)
Name label key
When this key is pressed so that the indicator illuminates, fixed stitch sewing of the number
of stitches (1-1999) in the E and F stitch number displays is carried out repeatedly.
2144M
(8)
Pleat presser sewing key
When this key is pressed so that the indicator illuminates, the number of backtack stitches
(1-1999) in the E stitch number display can be sewn by pressing the actuator.
(9)
Thread trimming key
2145M
x This can only be set for use together with the fixed stitch key (6) or the name label key
(7).
x When this key is pressed so that the indicator illuminates, the set number of stitches
(start or end backtack stitches or fixed stitches) are sewn, and then the thread is
trimmed automatically.
2146M
(10)
AUTO key
x This can only be set for use together with the continuous backtack key (5), the fixed
stitch key (6) or the name label key (7).
x When this key is pressed so that the indicator illuminates, the set number of stitches
(start or end backtack stitches, fixed stitches or thread trimming) are sewn automatically
simply by depressing the treadle once.
2147M
(11)
Sewing speed control display
This shows the sewing speed when the treadle is depressed to the maximum amount.
x If all bars are illuminated, it indicates that the maximum speed can be set.
x If all bars are switched off, it indicates the minimum speed (220 rpm).
2148M
(12)
Sewing speed control keys
These keys let you adjust the sewing speed that is used when the treadle is depressed to
the maximum amount.
The sewing speed can also be adjusted while sewing is in progress.
x When the
key is pressed, the sewing speed becomes faster.
x When the
key is pressed, the sewing speed becomes slower.
(13)
Thread trimming lock key
x When this key is pressed so that the indicator illuminates, the sewing machine stops in
the needle up position without thread trimming being carried out even if the treadle is
depressed backward.
x If the indicator of the AUTO key (10) is illuminated, the sewing machine stops in the
needle up position without thread trimming being carried out after the set number of
stitches have been sewn.
(14)
Half stitch key
2149M
2150M
2151M
2152M
When the sewing machine is stopped, the needle bar can be moved up and down by
pressing this key.
2153M
(15)
Lower thread counter display
This shows the lower thread counter value.
The counter is reduced by “1” for every ten stitches sewn.
(16)
Lower thread counter keys
These keys are used to set the initial value for the lower thread counter. (Refer to p.24.)
2154M
2155M
(17)
RESET key
This key is used to return the lower thread counter to its initial value and to cancel warning
conditions. (Refer to p.24.)
2156M
S-7220B
18
5. USING THE OPERATION PANEL (BASIC OPERATIONS)
5-2. Sewing start and end backtack stitches
0841M
1
Setting start backtack stitches
Example:
2
2157M
Setting end backtack stitches
Example:
2158M
3
Start backtacking is carried out. After it has finished, normal sewing continues for as long as
the treadle remains depressed.
NOTE:
If the treadle is returned to the neutral position, the sewing machine will continue
operating until the set number of start backtack stitches has been sewn.
2159M
4
End backtacking is carried out. After it has finished, the thread is trimmed automatically and
the sewing machine stops in the needle up position.
NOTE:
x If the treadle is depressed backward before sewing of the set number of start backtack
stitches is complete, end backtacking will not be carried out.
x If the indicator of the thread trimming lock key is illuminated, the sewing machine will
stop in the needle up position without thread trimming being carried out.
2160M
19
S-7220B
5. USING THE OPERATION PANEL (BASIC OPERATIONS)
5-3. Sewing continuous backtack stitches
3655M
1
Setting continuous backtack stitches
Example:
3656M
2
If the treadle is simply depressed continuously, the number of stitches set for A, B, C and D
will be sewn in a single cycle, the thread will be trimmed automatically and then the needle
bar will stop in the needle up position.
NOTE:
x If the treadle is returned to the neutral position while continuous backtacking is being
carried out, the sewing machine will stop at the point where the treadle returns to the
neutral position.If the treadle is depressed again, operation will resume from the point
where it was interrupted.
x If the indicator of the thread trimming lock key is illuminated, the sewing machine will
stop in the needle up position without thread trimming being carried out.
2159M
<Automatic sewing>
When the AUTO key is pressed to turn on the automatic sewing function, operation will be carried out
automatically from continuous backtack sewing through to thread trimming just by depressing the
treadle once, without needing to keep it depressed continuously.
S-7220B
20
5. USING THE OPERATION PANEL (BASIC OPERATIONS)
5-4. Sewing fixed stitches
0827M
1
2161M
Example:
From 1 to 1999 stitches can be set.
2
After the set number of stitches in E (fixed stitches) have been sewn, the sewing machine
stops in the needle position that has been set by the needle up/down key (refer to p.25). After
this, normal sewing is carried out if the treadle is depressed.
2159M
3
After the thread is trimmed, fixed stitch sewing mode is enabled.
2160M
<Automatic thread trimming>
Press the thread trimming key to turn on the thread trimming function. When the treadle is
continuously depressed, thread trimming is carried out after the fixed stitches have been sewn.
<Automatic sewing>
When the AUTO key is pressed to turn on the automatic sewing function, the fixed stitches are sewn
simply by depressing the treadle once without needing to depress it continuously.
<Start and end backtack sewing>
x The start backtack key and end backtack key can be pressed to turn on the backtack sewing
function.
x If changing the number of end backtack stitches in C and D, press the fixed stitch key to
temporarily turn off the fixed stitch function before making the change. (The CD display will show
the number of stitches and the setting can then be changed.)
21
S-7220B
5. USING THE OPERATION PANEL (BASIC OPERATIONS)
5-5. Sewing name labels
0835M
1
2162M
Example:
From 1 to 1999 stitches can be set for the E and F stitch numbers.
2
After the set number of stitches in E (fixed stitches) have been sewn, the needle bar stops in
the position that has been set by the needle up/down key (refer to p.25).
2159M
3
After the set number of stitches in F (fixed stitches) have been sewn, the needle bar stops in
the position that has been set by the needle up/down key (refer to p.25).
4
Repeat steps 2 and 3 above.
5
Thread trimming is carried out.
2160M
<If using a solenoid-type presser lifter>
After the fixed stitches in E and F are sewn, the presser foot is also lifted automatically.
<Automatic thread trimming>
Press the thread trimming key to turn on the thread trimming function. Thread trimming is carried out
automatically after the second set of F stitches has been sewn.
<Automatic sewing>
When the AUTO key is pressed to turn on the automatic sewing function, the fixed stitches in E and F
are sewn respectively simply by depressing the treadle once without needing to depress it
continuously.
<Start and end backtack sewing>
x The start backtack key and end backtack key can be pressed to turn on the backtack sewing
function.
x If changing the number of start and end backtack stitches in A, B, C and D, press the name label
stitch key to turn off the name label function before making the change. (The ABCD display will
show the number of stitches and the settings can then be changed.)
S-7220B
22
5. USING THE OPERATION PANEL (BASIC OPERATIONS)
5-6. Sewing pleat presser stitches
2163M
1
2164M
Example:
From 1 to 1999 stitches can be set.
2
If the treadle is continuously depressed and then
you press the actuator while sewing is in progress,
the number of backtack stitches set in E is sewn and
then normal sewing resumes.
3741M
3
Thread trimming is carried out.
2160M
<Automatic sewing and automatic thread trimming>
These functions cannot be used.
<Start and end backtack sewing>
x The start backtack key and end backtack key can be pressed to turn on the backtack sewing
function.
x If changing the number of end backtack stitches indicated in C and D, press the pleat presser
sewing key to turn off the pleat presser sewing function before making the change. (The CD display
will show the number of stitches and the setting can then be changed.)
23
S-7220B
5. USING THE OPERATION PANEL (BASIC OPERATIONS)
5-7. Using the lower thread counter
yThe lower thread counter can be used to let you know approximately how much lower thread is remaining.
yThe value displayed by the lower thread counter display is reduced by 1 from the initial setting value each time the sewing
machine sews 10 stitches, and a warning is given when the counter reaches “-5”.
<Initial value setting>
1
2
(Press for 2 seconds or more)
After about 2 seconds, the buzzer will sound and the lower thread counter display
will show the initial value which was set previously.
2166M
key is pressed, the setting increases.
yWhen the
key is pressed, the setting decreases.
yWhen the
yIf you hold down the keys, the setting will change more quickly.
yIf a value of “0” is set, the lower thread counter will not operate.
yThe initial setting value will be accepted when sewing starts.
2167M
<Lower thread counter operation>
Reduces by 1
(Initial value)
for every 10
stitches sewn
2168M
2169M
Press the
RESET key (2).
Press the RESET key (2)
for 2 seconds or more.
2170M
1. When sewing is carried out, the value shown in the lower thread counter display is reduced by 1 for every 10 stitches sewn.
(After the value reaches zero “0”, a minus sign appears and counting continues to a maximum of “-999”.)
2. When the value is “-5” or less, a warning icon (1) illuminates and an electronic buzzer sounds for 5 seconds.
3. After the treadle returns to the neutral position and the sewing machine stops, the sewing machine will not start up again
even if the treadle is depressed. However, thread trimming can be carried out by depressing the treadle backward.
yIf you press the RESET key (2), the warning icon (1) will disappear and sewing will be possible when the treadle is
depressed.
yIf you press and hold the RESET key (2) for 2 seconds or more, the display will return to the initial value.
S-7220B
24
6. USING THE OPERATION PANEL (ADVANCED OPERATIONS)
6. USING THE OPERATION PANEL
(ADVANCED OPERATIONS)
The operations described in this section should only be carried out by a technician.
6-1. Names and functions
These are used for making advanced
operating settings.
They should only be used by a technician.
(18)
2171M
Slow start key
x When this key is pressed so that the slow start icon (19) illuminates, the first two
stitches sewn after the thread is trimmed are sewn at 700 rpm. After this, the sewing
speed corresponds to the treadle depression amount.
x If you press this key again while the icon (19) is illuminated, the icon (19) will turn off.
2172M
(20)
Correction key
x When this key is pressed so that the correction icon (21) illuminates, correction sewing
can be carried out.
If the sewing machine is stopped, sewing will be carried out at slow speed (220 rpm)
while the actuator is being pressed.
NOTE:
x If you press the actuator while sewing is in progress, backtack stitches will be
sewn.
x Correction sewing cannot be carried out while the indicator of the pleat presser
sewing key (8) is illuminated.
x If you press this key again while the icon (21) is illuminated, the icon (21) will turn off.
2173M
(22)
Needle up/down key
Use this key to select whether the needle bar stops in the up position or the down position
when the treadle is returned to the neutral position and sewing stops.
x When the needle up icon
(23) is illuminated, the needle bar stops in the up position.
(24) is illuminated, the needle bar stops in the down
x When the needle down icon
position.
2207M 2208M 2174M
25
S-7220B
6. USING THE OPERATION PANEL (ADVANCED OPERATIONS)
6-2. Adjusting the needle up stop position
2210M
(–10 – 20)
1. While pressing the needle up/down key (1), turn on the
power switch.
2. “n.0 xx” will appear in the main display (2).
(“xx” is the setting value for the needle up stop position,
and “0” is the default setting.)
3. Press the
or
key (3) to change the setting value
for the needle up stop position.
x If you press the
key, the setting value will increase
up to 20 and the needle up stop position will become
lower.
x If you press the key, the setting value will decrease
down to -10 and the needle up stop position will
become higher.
4. Press the ENTER key (4) for two seconds or more.
A long buzzer will sound and the main display (2) will
change to stitch number display mode. (This completes
the needle up stop position setting.)
* A setting value of “10” corresponds to an angle of rotation
of approximately 10q for the upper shaft.
Becomes higher
Becomes lower
2138M
3657M
2139M
6-3. LOCK key
When the power switch is turned on, the LOCK key (1) turns
ON. (The icon (2) is illuminated.)
In this state, the following three key operations are disabled
so that the setting values cannot be changed accidentally.
FUNC key (3)
This key is used to make settings for various functions.
ENTER key (4)
This key is used to accept function settings.
MAX key (5)
This key is used to change the maximum sewing speed.
* Refer to the Service Manual for details on using these
keys.
2212M
6-4. Resetting all settings to their defaults
While holding down the RESET key, turn on the power switch.
If you press the ENTER key, the settings will then be reset.
Once the settings have been reset, “iniT ALL” appears in the display and the operation panel settings are reset to their factory
default settings.
Once the above display appears, normal operation will then be possible.
S-7220B
26
7. USING THE CONTROL BOX PANEL (BASIC OPERATIONS)
7. USING THE CONTROL BOX PANEL
(BASIC OPERATIONS)
NOTE
The control box panel will not operate when the machine head operation panel is connected.
7-1. Names and functions
Power indicator
3133M
The power indicator illuminates when the power switch is turned on.
(1)
Speed control
x This lets you adjust the sewing speed when the treadle is fully depressed.
x The sewing speed becomes faster when the speed control (1) is turned clockwise.
(2)
(3)
Start backtack indicator
Start backtack key
<For start and end backtacking mode>
When the start backtack key (3) is pressed so that the start backtack indicator (2) illuminates, the number of
start backtack stitches set for A and B (0-9) are sewn.
<For continuous backtacking mode>
When the start backtack key (3) is pressed so that the start backtack indicator (2) illuminates, the number of
stitches (0-9) set for A, B, C and D will be sewn continuously for a single cycle.
(4)
(5)
End backtack indicator
End backtack key
When the end backtack key (5) is pressed so that the end backtack indicator (4) illuminates, the number of end
backtack stitches set for C and D (0-9) are sewn.
NOTE: This key (5) and indicator (4) are only enabled during start and end backtacking mode.
(6)
Stitch number display
x This shows the backtacking processes (A, B, C and D) and the number of stitches for each.
NOTE: This is only displayed when making the settings.
x It also displays error codes.
27
S-7220B
7. USING THE CONTROL BOX PANEL (BASIC OPERATIONS)
7-2. Sewing start and end backtacking and continuous backtacking and
locking thread trimming
<Setting method>
Thread trimming not locked
Thread trimming locked
Thread trimming is carried out
Thread trimming
is carried out
Thread trimming is not carried out.
Thread trimming is
not carried out.
3658M
1
Activating setting mode
2
Switching between start and end backtacking mode and continuous backtacking mode
3659M
1. If the power is turned on, turn off the power switch (1)
temporarily.
2. While pressing the start backtack key (2), turn on the
power switch (1).
3660M
C: Mode switching
0: Start and end backtacking mode
1: Continuous backtacking mode
(For example 0: Start and
end backtacking mode)
1. Press the start backtack key (2) so that “C” is displayed in
the top row of the stitch number display.
2. Press the end backtack key (3) to set the mode in the
bottom row of the stitch number display.
3661M
(Continued on next page)
S-7220B
28
7. USING THE CONTROL BOX PANEL (BASIC OPERATIONS)
Setting the number of stitches for start and end backtacking and continuous backtacking
No. of stitches
3662M
3
1. Press the start backtack key (2) so that “A” is displayed in
the top row of the stitch number display.
2. Press the end backtack key (3) to set the number of
stitches for A in the bottom row of the stitch number
display.
Stitch number setting (A)
(Example: 4)
4
Stitch number setting (B)
3663M
1. Press the start backtack key (2) so that “b” is displayed.
2. Press the end backtack key (3) to set the number of
stitches for b.
(Example: 5)
3137M
5
Stitch number setting (C)
1. Press the start backtack key (2) so that “c” is displayed.
2. Press the end backtack key (3) to set the number of
stitches for c.
(Example: 7)
3138M
6
Stitch number setting (D)
1. Press the start backtack key (2) so that “d” is displayed.
2. Press the end backtack key (3) to set the number of
stitches for d.
(Example: 6)
3139M
29
S-7220B
7. USING THE CONTROL BOX PANEL (BASIC OPERATIONS)
7
Selecting “Thread trimming not locked” and “Thread trimming locked”
T: Thread trimming setting
0: Thread trimming not locked (normal)
1: Thread trimming locked
(For example 1: Thread trimming locked)
1. Press the start backtack key (2) so that “T” is displayed in
the top row of the stitch number display.
2. Press the end backtack key (3) to set either “Thread
trimming not locked” or “Thread trimming locked” in the
bottom row of the stitch number display.
3664M
8
Exiting setting mode
Set the power switch (1) to OFF.
3665M
Refer to the next page for details on sewing “Start and end backtacking” or “Continuous backtacking”.
S-7220B
30
7. USING THE CONTROL BOX PANEL (BASIC OPERATIONS)
<Start and end backtack sewing method>
1
Press the power switch (1) to turn on the power.
3141M
2
1. Press the start backtack key (2) so that the start backtack indicator (3)
illuminates.
2. Press the end backtack key (4) so that the end backtack indicator (5)
illuminates.
3
3142M
Start backtacking is carried out. After it has finished, normal sewing
continues for as long as the treadle remains depressed.
NOTE:
If the treadle is returned to the neutral position, the sewing machine will
continue operating until the set number of start backtack stitches has
been sewn.
4
2159M
End backtacking is carried out. After it has finished, the thread is trimmed
automatically and the sewing machine stops in the needle up position.
NOTE:
If the treadle is depressed backward before sewing of the set number of
start backtack stitches is complete, end backtacking will not be carried
out.
2160M
<Continuous backtack sewing method >
1
Press the power switch (1) to turn on the power.
3141M
2
Press the start backtack key (2) so that the start backtack indicator (3)
flashes.
3
31
3666M
If the treadle is simply depressed continuously, the number of stitches set for
A, B, C and D will be sewn in a single cycle, the thread will be trimmed
automatically and then the needle bar will stop in the needle up position.
NOTE:
yIf “Thread trimming locked” is set, the sewing machine will stop in the
needle up position without thread trimming being carried out.
yIf the treadle is returned to the neutral position while continuous
backtacking is being carried out, the sewing machine will stop at the
point where the treadle returns to the neutral position.If the treadle is
depressed again, operation will resume from the point where it was
interrupted.
2159M
S-7220B
8. USING THE CONTROL BOX PANEL (ADVANCED OPERATIONS)
8. USING THE CONTROL BOX PANEL
(ADVANCED OPERATIONS)
The operations described in this section should only be carried out by a technician.
NOTE:
The control box panel will not operate when the machine head operation panel is connected.
8-1. Before setting any functions
DANGER
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.
1
Control box
Set DIP switch -3 to OFF.
(This will cancel the lock so that the functions can be set.)
3143M
2
While pressing the end backtack key (2), press the power
switch (3) to turn on the power.
3144M
3
1. The top row of the stitch number display will change in
the order shown each time the start backtack key (4) is
pressed.
2. Select the display that matches the required setting, and
then make the setting. (Refer to section 8-2 and after.)
3145M
8-2. Changing the needle stop position
This sets whether the needle bar stops in the needle up stop position or the needle down stop position when the treadle is
returned to the neutral position and sewing stops.
1
1. Press the start backtack key (4) so that “n” is displayed in
the top row of the stitch number display.
2. Press the end backtack key (2) to set the “ ¯ ” or “ - ” in the
bottom row of the stitch number display.
Needle stops above the needle plate
Needle stops below the needle plate
3146M
2
Set DIP switch -3 to ON.
(The settings will be locked.)
S-7220B
32
8. USING THE CONTROL BOX PANEL (ADVANCED OPERATIONS)
8-3. Slow start
The first two stitches sewn after the thread is trimmed are sewn at a speed of 700 rpm. After this, the sewing speed
corresponds to the treadle depression amount.
1
1. Press the start backtack key (4) so that “S” is displayed in
the top row of the stitch number display.
2. Press the end backtack key (2) to set the value in the
bottom row of the stitch number display.
Slow start disabled
Slow start enabled
3147M
Set DIP switch -3 to ON.
(The settings will be locked.)
2
8-4. Correction sewing
This sews at slow speed (220 rpm) while the actuator is being pressed when the sewing machine is stopped.
1
1. Press the start backtack key (4) so that “c” is displayed in
the top row of the stitch number display.
2. Press the end backtack key (2) to set the value in the
bottom row of the stitch number display.
Correction sewing disabled
Correction sewing enabled
3148M
Set DIP switch -3 to ON.
(The settings will be locked.)
2
8-5. Initialization method
This returns the control box panel settings to the factory default settings.
1
1. Press the start backtack key (4) so that “r” is displayed in
the top row of the stitch number display.
2. Press the end backtack key (2) to set the value in the
bottom row of the stitch number display to “1”.
3149M
2
1.
(Display turns off)
2.
Then, press and hold the end backtack key (2) for 5
seconds or more. (The display will turn off.)
After this, “Ar” will flash and the initialization will be
complete.
(5 seconds or more)
3
33
3150M
Set DIP switch -3 to ON.
(The settings will be locked.)
S-7220B
8. USING THE CONTROL BOX PANEL (ADVANCED OPERATIONS)
8-6. Setting the needle up stop position and needle down stop position
Meaning of displays during setting
x The stop position is set numerically, and “A”
to “F” represent the numbers “10” to “15”
respectively.
x A setting value of “8” corresponds to an
angle of rotation of approximately 8° for the
upper shaft.
Display
A
b
c
d
E
F
Value
10
11
12
13
14
15
<Needle up stop position>
1
1. Press the start backtack key (4) so that “ ¯ ” is displayed
in the top row of the stitch number display.
2. Press the end backtack key (2) to set the value.
(Example: -8)
Becomes higher
Becomes lower
Becomes higher
Becomes lower
3657M
3151M
2
Set DIP switch -3 to ON.
(The settings will be locked.)
<Needle down stop position>
1
1. Press the start backtack key (4) so that “ - ” is displayed
in the top row of the stitch number display.
2. Press the end backtack key (2) to set the value.
(Example: 3)
Becomes lower
Becomes higher
3152M
2
Set DIP switch -3 to ON.
(The settings will be locked.)
S-7220B
34
9. SEWING
9. SEWING
CAUTION
Attach all safety devices before using the sewing machine. If the machine is used without these devices attached,
injury may result.
Turn off the power switch at the following times.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
yWhen threading the needle
yWhen replacing the bobbin and needle
yWhen not using the machine and when leaving the machine unattended
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.
Use both hands to hold the machine head when tilting it back or returning it to its original position. If only one hand
is used, the weight of the machine head may cause your hand to slip, and your hand may get caught.
9-1. Sewing
1. Carry out the programming which is necessary for sewing.
(Refer to “Using the operation panel (1)” or “Using the
control box panel (2)”.)
2. Depress the treadle to start sewing.
3743M
9-2. Backtacking
3744M
When the actuator (1) or the reverse lever (2) is pressed
during sewing, the feed direction will be reversed. When it is
released, the feed direction will return to normal.
3745M
35
S-7220B
9. SEWING
9-3. Sewing condensed stitches
yIf you press the actuator (1) or the reverse lever (2) while
sewing is in progress, you can sew stitches (forward
direction) with small stitch lengths.
yBefore carrying out sewing, set the stitch length for
condensed stitches as follows.
Sewing direction
Condensed stitches
3746M
3747M
Unlocked
Locked
<Setting>
1. Lift up the dial lock lever (3) to release the lock.
2. Turn the stitch length dial (4) to the stitch length to be
used for condensed stitches.
3. Tilt back the machine head.
4. Loosen the nut (5) and then turn the bolt (6) until its head
is touching the solenoid lever (7).
5. Tighten the nut (5) to secure the bolt (6).
6. Return the machine head to its normal position.
<Sewing>
1. Return the stitch length dial (4) to the stitch length for
normal sewing.
2. Push down the dial lock lever (3) to engage the lock.
3. Start sewing.
4. At the position where you would like to start sewing
condensed stitches, press the actuator (1) or the reverse
lever (2).
(Condensed stitches are sewn while the actuator (1) or
reverse lever (2) is being pressed.)
* To stop sewing condensed stitches, tighten the bolt (6) so
that its head is not touching the solenoid lever (7).
3673M
S-7220B
36
10. THREAD TENSION
10. THREAD TENSION
10-1. Adjusting the thread tension
CAUTION
Turn off the power switch before removing or inserting the bobbin case.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
Good even stitches
Upper thread
Lower thread
0572M
Upper thread tension too weak or
lower thread tension too strong
Increase the upper thread tension.
Decrease the lower thread tension.
Upper thread tension too strong
or lower thread tension too weak
Decrease the upper thread tension.
Increase the lower thread tension.
0573M
0574M
<Lower thread tension>
Adjust by turning the adjustment screw (1) until the bobbin
case drops gently by its own weight while the thread end
coming out of the bobbin case is held.
Becomes weaker
Becomes stronger
2177M
<Upper thread tension>
After the lower thread tension has been adjusted, adjust the
upper thread tension so that a good, even stitch is obtained.
1. Lower the presser foot.
2. Adjust by turning the tension nut (2).
Becomes weaker
Becomes stronger
3748M
37
S-7220B
10. THREAD TENSION
10-2. Adjusting the presser foot pressure
Correct stitches
Upper thread
0894M
Skipped stitches occur
0895M
Increase the pressure.
Uneven stitch length
0896M
Stitches are puckered
Decrease the pressure.
0897M
The presser foot pressure should be as weak as possible,
but strong enough so that the material does not slip.
Becomes weaker
1. Loosen the adjusting nut (1).
2. Turn the presser adjusting screw (2) to adjust the presser
foot pressure.
3. Tighten the adjusting nut (1).
Becomes stronger
3674M
10-3. Adjusting the trailing length after thread trimming
3749M
yAt the time of thread trimming, the thread tension is
loosened and tension is applied by the pretension (1) only.
yThe standard trailing length for the upper thread is 35-40
mm.
yIf the tension of the pretension (1) is increased, the
lengths of the threads trailing from the needle tips will be
reduced; if the tension is reduced, the lengths will be
increased.
Adjust by turning the pretension (1).
Shorter
Longer
3676M
S-7220B
38
11. CLEANING
11. CLEANING
CAUTION
Turn off the power switch before carrying out cleaning.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
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
diarrhea.
Keep the oil out of the reach of children.
Use both hands to hold the machine head when tilting it back or returning it to its original position. If only one hand
is used, the weight of the machine head may cause your hand to slip, and your hand may get caught.
11-1. Daily cleaning procedures
The followinig cleaning operations should be carried out each day in order to maintain the perfomance of this machine and to
ensure a long service life.
Furthermore, if the sewing machine has not been used for a long period of time, carry out the following cleaning procedures
before using it again.
1. Cleaning
1. Raise the presser foot.
2. Remove the two screws (1), and then remove the needle
plate (2).
3. Use a soft wire brush to clean any dust from the feed dog
(3).
4. Install the needle plate (2) with the two screws (1).
3750M
3736M
3751M
5. Tilt back the machine head.
6. Remove the bobbin case (4).
7. Wipe off any dust from the rotary hook (5) with a soft cloth,
and check that there is no damage to the rotary hook (5).
8. Remove the bobbin from the bobbin case (4) and clean
the bobbin case (4) with a cloth.
9. Insert the bobbin into the bobbin case (4), and then place
the bobbin case (4) back into the machine.
2184M
39
S-7220B
11. CLEANING
3678M
2. Lubrication
A. Gearbox oil quantity
NOTE:
yCheck the quantity of oil in the gearbox immediately
after tilting back the machine head.
When the machine head is left for long periods in the
tilted-back position, the amount of oil in the felt inside
the gearbox drops and the oil level seen from the oil
window (1) rises, so that it becomes impossible to
measure the actual oil level accurately.
yThe position of the oil level in the oil window (1) will
vary depending on the angle of the machine head.
Tilt back the machine head while the head rest (2) is
installed in the correct position as shown in the table
processing diagram on page 4 (refer to page 6).
<Checking the oil quantity>
The oil level should normally be approximately 2 mm above
the center reference line in the oil window (1). (70 ml of
lubricating oil is added to the gearbox at the time of shipment
from the factory.)
Approx. 2 mm
1. Look at the oil window (1) from directly in front.
2. If the oil level is below the normal level, add more
lubricating oil as described in the following procedure.
2186M
3679M
<Lubrication>
Use only the lubricating oil (Nisseki Mitsubishi Sewing Lube
10N; VG10) specified by Brother.㩷
* If this type of lubricating oil is difficult to obtain, the recommended
oil to use is <Exxon Mobil Essotex SM10; VG10>.
1. Remove the rubber cap (3).
2. Add lubricating oil until the oil level is approximately 2 mm
above the center reference line in the oil window (1).
Do not pour all of the lubricating oil in at once at this time.
Pour the lubricating oil 10 ml at a time while checking the
oil window (1).
NOTE:
Do not pour too much lubricating oil into the specified
location.
If too much oil is added, oil leaks may result.
3. Insert the rubber cap (3) securely.
4. Return the machine head to its original position.
NOTE:
The rubber cap (3) has a hole in it for adjusting the air
pressure.
When replacing the rubber cap (3) use only the
replacement part specified by Brother.
Approx. 2 mm
2188M
S-7220B
40
11. CLEANING
B. Oil tank oil quantity
Check the oil gauge window (1), and add more oil if the oil
gauge (2) is below the lower reference line.
(Refer to page 8.)
Upper reference
line
Lower reference
line
3752M
3. Checking
1. Replace the needle if it is bent or if the tip is broken.
2. Check that the upper threads have been threaded
correctly. (Refer to page 15.)
3. Carry out a test sewing.
3753M
41
S-7220B
11. CLEANING
11-2. Applying grease
[When “GrEASEUP” appears…when using the operation panel]
If “GrEASEUP” flashes on the main display (1) and a buzzer sounds when the power switch is turned on, it means that grease
needs to be applied. (The sewing machine will not operate at this time, even if the treadle is depressed.)
Apply grease as required, while referring to the following for details.
2191M
<To continue sewing without applying grease>
1. Press the RESET key (2).
2. The main display (1) will change to stitch number display mode, and sewing will be possible when the treadle is depressed.
(The power indicator (3) will keep flashing.)
NOTE
࡮If you do not apply grease when the “GrEASEUP” notification appears, the notification will continue to appear and the
power indicator (3) will flash each time the power is turned on until you reset the notification by carrying out the
procedure on the following page.
࡮If you continue to use the sewing machine after the “GrEASEUP” notification appears without applying grease (or
without carrying out the reset procedure), “Err100” will appear after a certain period of time and the sewing machine will
be forcibly prevented from operating for safety reasons.
If this happens, apply grease and carry out the reset procedure.
* If you continue to use the sewing machine after carrying out the reset procedure but without applying grease,
problems with the sewing machine may result.
<Applying grease>
Use Brother-specified grease (SA7300-001).
Using the tube
3682M
(Continued on next page)
S-7220B
42
11. CLEANING
<-403, 405, 433 specifications>
<-433 specifications>
grease
1. Turn the pulley to raise the needle bar to a
position where the slide block guide (1) can be
seen.
2. Apply grease to the slide block guide (1) in the
places shown in the illustration.
3755M
3754M
1.
2.
3.
4.
Turn the power switch to “OFF”.
Remove the screws.
Apply grease to each of the holes until the grease overflows slightly.
The grease will be pushed in when the screws are tightened.
5. Turn the machine pulley by hand to move the needle bar
up and down several times in order to disperse the
grease.
6. Use a cloth to wipe away any excess grease from around
the screws.
7. Carry out the reset procedure given below.
3756M
<Resetting the grease consumption amount>
After the grease has been applied, carry out the following procedure to reset the grease consumption amount.
1. Turn the power switch to “ON”. “GrEASEUP” will flash in the main display (1) and the buzzer will sound.
2. Press the RESET key (2). The main display (1) will change to stitch number display mode.
3. Press and hold the LOCK key (4) for 2 seconds or more.
The lock icon (5) will switch off and the lock will be released.
4. Press the FUNC (Function) key (6). “n.134 Pxxx” will appear in green in the main display (1).
(“Pxxx” indicates the grease consumption amount. For example, “P100” means that 100% of the grease has been
consumed.)
5. Press the rightmost
key (7). The “Pxxx” will change to “P 0”.
6. Press and hold the ENTER key (8) for two seconds or more.
The buzzer will make a long beep, and then the main display (1) will change to stitch number display mode.
7. Depress the treadle to run the sewing machine for 1 second or more.
2139M
8. Turn the power switch to “OFF”. (This completes the reset procedure.)
43
S-7220B
11. CLEANING
11-3. Applying grease
[When “GU” appears ... when using the control box panel]
DANGER
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.
If “GU” flashes in the stitch number display (1) on the control box panel when the power switch is turned on, it indicates that it
is time for grease to be applied. (The sewing machine will not operate at this time, even if the treadle is depressed.)
Apply grease as required, while referring to the following for details.
3704M
<To continue sewing without applying grease>
1. Press the start backtack key (3).
2. The “GU” in the stitch number display (1) will stop flashing and disappear, and sewing will be possible when the treadle is
depressed.
(The power indicator (2) will flash.)
NOTE
࡮“GU” will appear each time the power is turned on until you apply grease and reset the notification by carrying out the
reset procedure on the following page.
࡮If you continue to use the sewing machine after the “GU” notification appears without applying grease (or without
carrying out the reset procedure), “-0” will appear in the stitch number display (1) after a certain period of time and the
sewing machine will be forcibly prevented from operating for safety reasons.
If this happens, apply grease and carry out the reset procedure.
* If you continue to use the sewing machine after carrying out the reset procedure but without applying grease,
problems with the sewing machine may result.
<Applying grease>
Use Brother-specified grease (SA7300-001).
Using the tube
3682M
(Continued on next page)
S-7220B
44
11. CLEANING
<-403, 405, 433 specifications>
<-433 specifications>
grease
1. Turn the pulley to raise the needle bar to a
position where the slide block guide (1) can be
seen.
2. Apply grease to the slide block guide (1) in the
places shown in the illustration.
3755M
3754M
3756M
1. Turn the power switch to “OFF”.
2. Remove the screws.
3. Apply grease to each of the holes until the grease
overflows slightly.
4. The grease will be pushed in when the screws are
tightened.
5. Turn the machine pulley by hand to move the needle bar
up and down several times in order to disperse the
grease.
6. Use a cloth to wipe away any excess grease from
around the screws.
7. Carry out the reset procedure given below.
<To continue sewing without applying grease>
After the grease has been applied, carry out the following procedure to reset the grease consumption amount.
1. Set DIP switch -3 inside the control box to OFF.
(This will cancel the lock so that the functions can be set.)
2. While pressing the end backtack key (4), press the power switch to turn on the power.
3. Press the start backtack key (3) so that “G” is displayed in the top row of the stitch number display.
4. Press the end backtack key (4) to set the value in the bottom row of the stitch number display to “1”.
5. Then, press and hold the end backtack key (4) for 5 seconds or more.
(The display will turn off.)
6. After this, “Gr” will flash and the reset operation will be complete.
7. After the reset operation is complete, set DIP switch -3 to ON. (The settings will be locked.)
45
S-7220B
12. ADJUSTING THE ROTARY HOOK LUBRICATION AMOUNT
12. ADJUSTING THE ROTARY HOOK LUBRICATION
AMOUNT
CAUTION
Be careful not to touch your fingers or the lubrication amount check sheet against moving parts such as the rotary
hook or the feed mechanism when checking the amount of oil supplied to the rotary hook, otherwise injury may
result.
Use the following procedure to check the amount of oil being supplied to the rotary hook when replacing the rotary hook or
when changing the sewing speed.
2303M
Approx. 25mm
Approx. 70mm
<Checking the lubrication amount>
1. Remove the thread from all points from the thread take-up
to the needle.
2. Use the lifting lever to lift the presser foot.
3. Run the machine at the normal sewing speed for
approximately 1 minute without sewing any material
(following the same start/stop pattern as when actually
sewing).
4. Place the lubrication amount check sheet (1) underneath
the rotary hook (2) and hold it there. Then run the sewing
machine at the normal sewing speed for 8 seconds. (Any
type of paper can be used as the lubrication amount
check sheet (1).)
5. Check the amount of oil which has spattered onto the
sheet.
Bed
5–10mm
2304M
NOTE:
If the lubrication amount does not match the correct
amount shown in the illustration at left (if the amount of
spattered oil is too much or none at all), turn the adjusting
screw (3) clockwise to fully tighten it, turn it back
counterclockwise by 2 1/2 turns, and then carry out the
following adjustment.
Spattered oil
Too much
Correct
If adjustment is necessary, carry out the following operations
in “Adjusting the lubrication amount”.
Too little
0935M
<Adjusting the lubrication amount>
1. Tilt back the machine head.
2. Turn the adjusting screw (3) to adjust the lubrication
amount.
Less oil
More oil
3686M
࡮If the rotary hook adjusting screw (3) is turned
clockwise, the lubrication amount becomes greater.
࡮If the rotary hook adjusting screw (3) is turned
counterclockwise, the lubrication amount becomes
smaller.
3. Check the lubrication amount again according to the
procedure given in “Checking the lubrication amount”
above.
* Turn the adjusting screw (3) and check the lubrication
amount repeatedly until the lubrication amount is
correct.
4. Check the lubrication amount again after the sewing
machine has been used for approximately two hours.
S-7220B
46
13. STANDARD ADJUSTMENTS
13. STANDARD ADJUSTMENTS
CAUTION
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 treadle is
depressed by mistake, which could result in injury.
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.
䊶㩷 When carrying out inspection, adjustment and
maintenance
䊶㩷 When replacing consumable parts such as the
rotary hook and knife
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.
If the power switch needs to be left on when carrying
out some adjustment, be extremely careful to
observe all safety precautions.
Use both hands to hold the machine head when
tilting it back or returning it to its original position. If
only one hand is used, the weight of the machine
head may cause your hand to slip, and your hand
may get caught.
13-1. Adjusting the actuator position
The installation position for the actuator (1) can be adjusted
to <A> or <B>.
Adjust so that it is in a position where it is easy to operate.
1. Remove the two screws (2).
2. Move the switch setting base (3) to move the actuator (1)
to the preferred position <A> or <B>.
3. Tighten the two screws (2).
Back
3757M
3758M
47
S-7220B
13. STANDARD ADJUSTMENTS
13-2. Adjusting the safety switch position
The safety switch (1) is normally installed as shown in figure
[A].
However, if the processing method used for the table leaves
too much space between the machine head and the table
hole, it may adversely affect the operation of the safety
switch (1).
3689M
<Adjustment method>
The standard amount of clearance between the machine
head and the table hole is 1.5 mm.
If the clearance is 3.5 mm or more, install the safety switch
(1) so that the washer (2) is on the machine head side as
shown in Figure [B].
* If the position cannot be satisfactorily adjusted in this way,
add more washers of the same thickness.
<Safety switch operation>
3691M
If the spring stroke is to small, the safety
switch will not operate.
3.5 mm or more
Sewing
machine
Table
Clearance
is too large.
By changing the position of the safety switch,
the required spring stroke can be maintained.
Reduce the clearance.
3690M
S-7220B
3692M
48
13. STANDARD ADJUSTMENTS
13-3. Adjusting the thread take-up spring
<Thread take-up spring position>
The standard position of the thread take-up spring (1) is 6-8
mm [4-6 mm for -405 specifications] above the surface of the
thread guide (3) when the presser foot (2) is lowered.
1. Lower the presser foot (2).
2. Loosen the set screw (4).
3. Turn the thread tension bracket (5) to adjust the spring
position.
4. Securely tighten the set screw (4).
<-4[]3>
6 - 8 mm
<-405>
4 - 6 mm
3759M
3760M
<Thread take-up spring tension>
The standard tension of the thread take-up spring (1) varies
in accordance with the machine specifications as shown in
the table.
-4[]3 specifications
-405 specifications
0.25 - 0.35N
0.30 - 0.5N
1. Push the needle thread with your finger until it is slightly
higher than the thread tension bracket (5) and so that the
upper thread is not pulled out.
2. Pull the upper thread down until the thread take-up spring
(1) is at the same height as the base of the thread guide
(3), and then measure the tension of the thread take-up
spring (1).
3. Insert a screwdriver into the slot of the tension stud (6),
and turn the screwdriver to adjust the tension of the
thread take-up spring (1).
Scale
NOTE: If using the tension gauge (7) (sold separately) to
measure the tension, take the reading from the scale
on the side of the red line.
<-4[ ]3>
0.25 - 0.35N
<-405>
0.3 - 0.5N
3761M
49
S-7220B
13. STANDARD ADJUSTMENTS
13-4. Adjusting arm thread guide R
Becomes greater
The standard position of arm thread guide R (1) is the
position where the screw (2) is in the center of the adjustable
range for arm thread guide R (1).
Becomes less
* To adjust the position, loosen the screw (2) and then
move arm thread guide R (1).
࡮When sewing thick material, move arm thread guide R
(1) to the left. (The thread take-up amount will become
greater.)
࡮When sewing thin material, move arm thread guide R
(1) to the right. (The thread take-up amount will
become less.)
3762M
13-5. Adjusting the presser foot height
The standard height of the presser foot (1) is 6 mm when the
presser foot (1) is raised by means of the lifting lever (2).
1. Loosen the nut (3) of the adjustment screw (4), and then
turn the adjustment screw (4) so that there is no pressure
applied to the presser foot.
2. Raise the lifting lever (2). The presser foot (1) will also
rise.
3. Remove the oil cap (5).
4. Loosen the bolt (6) and then move the presser bar (7) up
or down until the presser foot (1) is at the standard height
of 6 mm.
5. Tighten the bolt (6).
6. Replace the oil cap (5).
7. Adjust the presser foot pressure using the adjustment
screw (4), and then tighten the nut (3).
3763M
S-7220B
50
13. STANDARD ADJUSTMENTS
13-6. Adjusting of the feed dog height
The standard height of the feed dog (1) when it is at its
maximum height above the top of the needle plate is 1.0 mm
for -4[]3 specifications, and 1.2 mm for -405 specifications.
<-4[]3>
1.0 mm
<-405>
1.2 mm
3764M
1. Turn the pulley until the feed dog (1) rises to the highest
position.
2. Tilt back the machine head.
3. Loosen the screw (2).
4. Turn the feed lifting rock bracket stud (3) within a range of
90° from the reference line (4) to adjust the vertical height
of the feed bar (5). (Fig. [A])
5. Tighten the screw (2).
Becomes
higher
* If you are worried about the angle of the feed dog (1), turn
the shaft (6) while carrying out the above adjustment. (Fig.
[B])
(Refer to “13-7. Adjusting the feed dog angle” on the next
page for details of this operation.)
Becomes
lower
3765M
Becomes higher
Needle plate
Becomes lower
Becomes higher
Becomes lower
3766M
Becomes higher
Becomes lower
3767M
51
S-7220B
13. STANDARD ADJUSTMENTS
13-7. Adjusting the feed dog angle
The standard angle is for the feed dog (1) to be parallel to the
needle plate when the machine pulley is turned forward to
raise the feed dog (1) from its lowest position until it is flush
with the top of the needle plate.
1. Turn the machine pulley forward to raise the feed dog (1)
from its lowest position until it is flush with the top of the
needle plate, and stop turning the pulley at that point.
2. Tilt back the machine head.
3. Loosen the two set screws (4).
4. Turn the shaft (2) in the direction of the arrow within a
range of 90° with respect to the standard position. (Fig.
[C])
Raise the front
Lower the front
࡮In order to prevent puckering, lower the front of the
feed dog (1).
࡮In order to prevent the material from slipping, raise the
3768M
front of the feed dog (1).
5. Securely tighten the set screws (4).
Raise the front
Parallel
Needle
plate
* If you would like to tilt the feed dog (1) further, turn the
feed lifting rock bracket stud (5) while carrying out the
above adjustment. (Fig. [D])
(Refer to “13-6. Adjusting the feed dog height” on the
previous page for details of this operation.)
* The height of the feed dog (1) will change after the angle
has been adjusted, so it will be necessary to re-adjust the
height of the feed dog (1).
Lower the front
3769M
Back is lowered
Back is raised
Raise the front
Lower the front
3770M
S-7220B
52
13. STANDARD ADJUSTMENTS
13-8. Adjusting the needle bar height
3771M
Adjust so that the distance from needle plate mounting
surface A to the bottom edge of the needle bar (1) is the
same as the height of surface B on the <1> side of the
accessory timing gauge (2) when the needle bar (1) is at its
lowest position as shown in the illustration.
1. Remove the presser foot (3), the needle plate (4) and the
feed dog (5).
2. Turn the machine pulley to set the needle bar (1) to its
lowest position.
3. Remove the rubber cap (6) from the face plate.
4. Loosen the screw (7).
5. Move the needle bar (1) up or down to adjust so that the
distance from needle plate mounting surface A to the
bottom edge of the needle bar (1) is the same as the
height of surface B on the <1> side of the accessory
timing gauge (2).
6. Securely tighten the screw (7).
7. Install the rubber cap (6).
8. Install the feed dog (5), the needle plate (4) and the
presser foot (3).
<Presser foot
including
finger guard>
3772M
53
S-7220B
13. STANDARD ADJUSTMENTS
13-9. Adjusting the needle and feed mechanism timing
<-4[]3>
<-405>
Approx.
2 mm
3773M
Approx.
4 mm
The standard timing is for the tip of the needle to be in the
position given below when the machine pulley is turned
forward to raise the feed dog (1) from its lowest position until
it is flush with the top of the needle plate (2).
(At this time, the “-” mark on the lower shaft will be aligned
with the center of the scale (4) (“O” mark) on the vertical cam
(3).)
<-4[]3>… There is a gap of approximately 2 mm between
the tip of the needle and the top of the needle
plate (2).
<-405>… There is a gap of approximately 4 mm between
the tip of the needle and the top of the needle
plate (2).
1. Set the stitch length dial to the maximum setting.
2. Tilt back the machine head.
3. Loosen the two set screws (5), and then turn the vertical
cam (3) sligtly to adjust the timing.
NOTE: Use the standard needle and feed mechanism
timing.
If the timing is changed, broken needles may
occur.
4. After adjustment is completed, securely tighten the two
screws (5).
(Standard)
3774M
S-7220B
54
13. STANDARD ADJUSTMENTS
13-10. Adjusting the needle and rotary hook timing
When the machine pulley is turned forward to raise the
needle bar (1) 1.8 mm (2.2 mm for -405 specifications) from
its lowest position, the rotary hook tip (3) should be aligned
with the center of the needle (4) as shown in the illustration
when the distance from needle plate mounting surface A to
the bottom edge of the needle bar (1) is the same as the
height of surface C on the <2> side of the accessory timing
gauge (2).
(At this time, the gap between the upper edge of the needle
hole and the rotary hook tip (3) will be 0.5 - 0.7 mm.)
1. Remove the presser foot (5), needle plate (6) and feed
dog (7).
2. Set the stitch length dial as follows.
0.5 - 0.7 mm
<-4[]3> 1.8 mm
<-405> 2.2 mm
3775M
0 - 0.05 mm
0 - 0.05 mm
3776M
<-4[]3>… Stitch length dial 0 setting.
<-405>… Stitch length dial 3 setting.
3. Loosen two of the three set screws (9) which are securing
the rotary hook (8).
4. Turn the machine pulley to raise the needle bar (1) from
its lowest position until the distance from needle plate
mounting surface A to the bottom edge of the needle bar
(1) is the same as the height of surface C on the <2> side
of the accessory timing gauge (2).
5. Loosen the remaining set screw (9) and align the rotary
hook tip (3) with the center of the needle (4). There should
be a gap of 0 - 0.5 mm between the rotary hook tip (3)
and the needle (4) at this time.
6. Securely tighten the three set screws (9).
7. Install the feed dog (7), needle plate (6) and presser foot
(5).
<Presser foot
including
finger guard>
3777M
<Checking the clearance between the rotary hook and
bobbin case holder position bracket>
Check that the clearance between the rotary hook (8) and the
bobbin case holder position bracket (10) is enough to allow
the thread being used to pass through smoothly.
The clearance should be 0.4 - 0.7 mm for -4[]3 models, and
0.6 - 1.1 mm for -405 models.
<Seen from above>
<-4[]3> 0.4 - 0.7 mm
<-405> 0.6 - 1.1 mm
3778M
55
S-7220B
13. STANDARD ADJUSTMENTS
13-11. Adjusting the treadle
2301M
<Forward depression sensitivity adjustment>
If the machine starts running at low speed when your foot is
simply resting on the treadle, or if the treadle pressure is felt
to be too weak, adjust the position (a to c) at which the
treadle spring (1) is hooked onto the treadle lever (2).
* a is the weakest position, and it becomes gradually
stronger at b and c respectively.
<Backward depression sensitivity adjustment>
1. Loosen the nut (3) and turn the bolt (4).
* When the bolt (4) is tightened, the treadle operation
becomes heavier, and when it is loosened, the
operation becomes lighter.
2. Tighten the nut (3).
<Adjusting the treadle stroke>
Remove the nut (5), and then move the connecting rod joint
(6) from the position in figure A to the position in figure B.
The treadle stroke will then be increased by approximately
27 %.
At this time, the treadle forward and backward depression
sensitivity will change, so readjust if necessary.
2302M
13-12. Adjusting the presser foot floating amount (minute lifting amount)
3779M
Floating amount
When sewing stretch materials and materials with long pile,
you can make minute adjustments to the floating amount for
the presser foot (1) in accordance with the material.
1. Turn the sewing machine pulley by hand to move the feed
dog (2) below the needle plate (3).
2. Use the lifting lever to lower the presser foot (1).
3. Loosen the nut (4).
4. Use a screwdriver to turn the adjustment screw (5) to
adjust the floating amount.
࡮To raise the presser foot (1) ...
Turn the adjusting screw (5) clockwise.
࡮To lower the presser foot (1) ...
Turn the adjusting screw (5) counterclockwise.
5. Tighten the nut (4).
* After making the adjustment, sew a piece of material to
check the floating amount.
Raise
Lower
3780M
S-7220B
56
14. TROUBLESHOOTING
14. TROUBLESHOOTING
yPlease check the following points before calling for repairs or service.
yIf the following remedies do not fix the problem, turn off the power switch and consult a qualified technician or the place of
purchase.
DANGER
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.
CAUTION
Turn off the power switch and disconnect the power cord before carrying out troubleshooting.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
14-1. Sewing
Items with a “*” in the “Page” column should only be checked by a qualified technician.
Problem
1
Upper thread is not tight.
Possible cause
Page
yIs the upper thread tension too weak, or is the lower thread tension
too strong?
Adjust the upper thread tension or lower thread tension.
37
yIs the lower thread tension too weak, or is the upper thread tension
too strong?
Adjust the lower thread tension or upper thread tension.
37
0573M
2
Lower thread is not tight.
0574M
3
Loops appear in seam.
yIs the thread path not smooth enough?
Use a file with a fine grain or sandpaper to polish smooth the
thread path.
yIs the bobbin not turning smoothly?
Pull out the lower thread to check that there is no slackness in
the thread tension, or replace the bobbin or bobbin case.
0977M
4
Skipped stitches
while sewing
occur
0470M
57
yIs the needle tip bent? Is the needle tip blunt?
If the needle tip is bent or broken, replace the needle.
yIs the needle properly installed?
If it is incorrect, install the needle correctly.
yIs the machine properly threaded?
If it is incorrect, thread the thread correctly.
yIs the presser foot pressure too weak?
Adjust the presser foot pressure.
yIs the needle too thin?
Replace the needle with a needle that is one rank thicker.
yIs the presser foot too high?
Adjust the height of the presser foot.
yIs the thread take-up spring too weak?
Adjust the tension of the thread take-up spring.
yIs the needle and rotary hook timing correct?
Adjust the height of the needle bar.
Adjust the clearance between the needle and the tip of the
rotary hook.
S-7220B
13
15
38
50*
49*
53*
55*
14. TROUBLESHOOTING
Problem
5
Possible cause
Skipped stitches at sewing
start
Thread
unravelling
at
sewing start
0749M
6
yIs the thread take-up spring tension too strong?
Reduce the tension of the thread take-up spring.
yIs the thread take-up spring operating range too large?
Lower the position of the thread take-up spring.
yAre the trailing lengths of the upper threads too short after thread
trimming?
Adjust the pretension.
yAre the threads not being trimmed cleanly?
Sharpen the fixed knives, or replace the fixed and movable
knives if necessary.
yIs the needle too wide?
Try using a needle with a count that is one lower than the
current needle.
yIs the length of thread trailing out from the bobbin case after thread
trimming too short.
If the bobbin is spinning loosely, replace the anti-spin spring in
the bobbin case.
yIs the sewing speed too fast at the sewing start?
Use the slow start feature.
yIs the needle up stop position too high?
Adjust the needle up stop position.
yIs the presser foot pressure too weak?
Adjust the presser foot pressure.
yIs the feed dog too low?
Adjust the feed dog height.
yIs the bobbin scratched?
If the bobbin is damaged, smooth it with an oiled grindstone or
replace it.
Uneven seam
Page
49*
49*
38
*
13
25, 33*
26,34*
38
51*
0473M
7
Large degree of puckering
(excess tension)
yIs the upper thread tension too strong?
Make the upper thread tension as weak as possible.
yIs the lower thread tension too strong?
Make the lower thread tension as weak as possible.
yIs the needle tip blunt?
Replace the needle if it is blunt.
yIs the needle too thick?
Replace with as thin a needle as possible.
yAre the thread take-up spring tensions too strong?
Make the thread take-up spring tension as weak as possible.
yIs the thread take-up spring operating range too large?
Lower the position of the thread take-up spring to as low a
position as possible.
yIs the presser foot pressure too strong?
Adjust the presser foot pressure.
yIs the sewing speed too fast?
Use the sewing speed control keys to gradually reduce the
sewing speed.
yIs the angle of the feed dog correct?
Tilt the front of the feed dog down slightly.
37
37
49*
49*
38
18
52*
0978M
S-7220B
58
14. TROUBLESHOOTING
Problem
8
Possible cause
Lower thread is tangled at
the sewing start.
Spinning of bobbin during
thread trimming
Lower
thread
yIs the bobbin spinning direction correct when the lower thread is
being pulled?
Set the bobbin so that it turns in the opposite direction to the
rotary hook.
yIs there too much thread
wound onto the bobbin?
The
bobbin
winding
amount should not be
more that 80 %.
2124M
yIs the anti-spin spring attached?
Attach the anti-spin spring.
yIs the bobbin turning smoothly?
If the bobbin is not turning smoothly, replace the bobbin.
yIs a bobbin other that the light-alloy bobbins specified by Brother
being used?
Use only bobbins which are specified by Brother.
Page
14
14
13
13
0751M
9
Upper and lower threads
are breaking.
yIs the needle bent or is the needle tip broken?
Replace the needle if it is bent or broken.
yIs the needle properly installed?
If it is incorrect, install the needle correctly.
yIs the machine properly threaded?
If it is incorrect, thread the thread correctly.
yIs the rotary hook sufficiently lubricated?
If the oil gauge is down to the lower reference line in the oil
gauge window, add more oil.
yIs the upper or lower thread tension too weak or too strong?
Adjust the upper thread or lower thread tension.
yIs the upper thread may be loose because the thread take-up spring
operating range is too small?
Adjust the position of the thread take-up spring.
yIs the rotary hook, feed dog or other part damaged?
If they are damaged, smooth them with an oiled grindstone or
replace the damaged parts.
yIs the thread path damaged?
If the thread path is damaged, smooth it with sandpaper or
replace the damaged part.
13
15
8
37
49*
*
*
0471M
10
11
59
Incorrect thread trimming
(Upper and lower threads
are
both
not
being
trimmed)
yIs the fixed knife or movable knife damaged or worn?
Replace the fixed knife or the movable knife.
Incorrect thread trimming
(Upper thread or lower
thread
is
not
being
trimmed)
yIs the needle properly installed?
If it is incorrect, install the needle correctly.
yIs the fixed knife or movable knife blunt?
Replace the fixed knife or the movable knife.
S-7220B
*
13
*
14. TROUBLESHOOTING
Problem
12
Possible cause
Page
yIs the material being pushed or pulled with excessive force during
sewing?
yIs the needle properly installed?
If it is incorrect, install the needle correctly.
yIs the needle bent, is the needle tip broken, or is the needle hole
blocked?
Replace the needle.
yIs the needle and rotary hook timing correct?
Adjust the height of the needle bar.
Adjust the clearance between the needle and the tip of the
rotary hook.
yIs the needle and feed mechanism timing correct?
Adjust to the standard timing.
Broken needles
13
53*
55*
54*
Caution
yIt is extremely dangerous to leave any pieces of broken
needle sticking in the material. If the needle breaks, search
for all pieces until the whole of the needle is found again.
yFurthermore, we recommend we recommend that through
steps be taken to account for such needles to comply with
product liability regulations.
0469M
13
Oil gauge (1) is not visible
in oil gauge window.
yIs the oil tank empty?
Fill the oil tank with oil.
8
2195M
14
Machine does not operate
when power is turned on
and treadle is pressed.
yIs the power supply connector
disconnected from the control
box?
Insert
the
connector
securely.
11
2196M
15
16
Machine does not operate
at high speed.
yIs the sewing speed setting or backtack speed setting incorrect?
Use the sewing speed control keys to set the high speed.
Machine
sewing.
yIs the fixed stitch key turned on?
Press the fixed stitch key so that the indicator turns off.
yIs the power supply voltage too low?
Check the power supply.
(If the power cord is too long or too many appliances are being
run from a single outlet, this may cause voltage drops which will
in turn cause the reset function to activate and stop the
machine, even if the power supply itself is normal.)
stops
during
S-7220B
18
18
*
60
14. TROUBLESHOOTING
Problem
17
Nothing appears on the
operation panel display.
Possible cause
yIs the power supply connector
disconnected from the control
box?
Insert
the
connector
securely.
yIs
the
operation
Page
2196M
11
panel
connector inside the control
box disconnected?
Insert
the
connector
securely.
10*
3154M
18
61
“GrEASEUP”
or
“GU”
flashes in the panel
display when the power
switch is turned on.
yThis display is to notify you that it is time to apply grease.
Apply grease.
S-7220B
42, 44*
14. TROUBLESHOOTING
14-2. Error code displays
If an error code appears on the operation panel display
1. Make a note of the error code and then turn off the power.
2. After the operation panel display has turned off, eliminate the cause of the error and then turn
the power back on.
2198M
yItems with a “ * ” in the “Page” column should only be checked by a qualified technician.
yFor items with “ ** ” appearing in the “Page” column, ask the place of purchase for advice.
Error code
Err
1
(Overvoltage)
Possible cause
Page
yDoes the power supply voltage match the
control box voltage specifications?
Check the voltage.
*
Voltage rating label
yIs the power supply voltage abnormally high?
Check.
yProblem with control box.
Replace the control box.
*
**
2199M
Err
2
(Overcurrent)
yIs the electrical equipment connector inside
the control box disconnected?
Insert the connector securely.
*
3155M
Err
3
(Encoder error)
yIs the encoder connector inside the control
box disconnected?
Insert the connector securely.
10*
3156M
Err
(Motor lock)
4
yIs the motor connector disconnected from the
control box?
Insert the connector securely.
11
yHas the machine locked up?
Turn off the power and then turn the machine pulley by hand and check that it
turns easily.
2202M
S-7220B
62
14. TROUBLESHOOTING
Error code
Err
5
(Safety switch
operated)
Possible cause
Page
yIs the machine connector inside the control
box disconnected?
Insert the connector securely.
10*
yIs the machine head tilted back?
Return the machine head to its normal position.
Check the operation of the safety switch.
48*
3157M
Err
6
(Voltage drop)
Err
7
(Panel
communication
error)
yWas the power turned on while the treadle was still depressed?
Return the treadle to the neutral position, and then turn on the power switch.
yIs the power supply voltage too low?
Check the power supply voltage.
*
This is displayed when there is a problem communicating with the operation panel
CPU.
yIs the operation panel connector inside the control box disconnected?
Insert the connector securely.
*
yProblem with operation panel or control box.
Replace the operation panel or control box.
**
3154M
Err
8
yThis appears on the display when the sewing machine has been operating
continuously for 3 minutes or more.
Turn the power switch off and then back on again, and then operate the
sewing machine normally.
9
yThis is displayed when the motor becomes abnormally hot and the temperature
protection has activated.
After the temperature has dropped, turn the power switch back on and operate
the sewing machine as normal.
yProblem with motor.
Replace the motor.
(Over time)
Err
(Motor
overheating
abnormally)
Err
10
(Solenoid
overcurrent)
Err
11
yThis is displayed when there is overcurrent in any of the solenoids (thread trimming,
thread wiping, quick reverse or presser lifter).
Check the resistances of the solenoids.
yProblem with control P.C. board.
Replace the control box.
yIs connector CN5 inside the motor disconnected?
Insert the connector securely.
3116M
S-7220B
**
**
*
(Problem with
motor overheating sensor)
63
**
14. TROUBLESHOOTING
Error code
Err
12
Possible cause
Page
yIs solenoid fuse F2 (5A) blown?
Replace the fuse.
*
(Solenoid power
supply error)
yProblem with control P.C. board.
Replace the control box.
**
3702M
Err
13
(Treadle unit
error)
yIs the treadle unit connector inside the control
box disconnected?
Insert the connector securely.
*
yIs there an open circuit in the treadle
connector harness?
Replace the treadle unit.
**
3158M
Err
14
(Head detector
unit error)
yProblem with head detector unit
Check that the head detector unit
connector inside the control box is
securely inserted.
Replace the head detector unit.
*
**
3703M
Err
15
(Problem with
sewing machine
motor operation)
Err
16
(Thread trimming
solenoid timeout)
Err
18
(EEROM error)
Err
19
(Control box
overheating)
Err
20
(Treadle pedal
position error)
yProblem with motor.
Replace the motor.
yProblem with power P.C. board.
Replace the control box.
**
**
yThis is displayed if the sewing machine motor locks during thread trimming.
Remove any thread scraps that may be blocking the motor.
Check that there are no problems with the thread trimming mechanism.
*
**
yThis is displayed if data could not be correctly read from or written to the memory
element on the control P. C. board.
Replace the control box.
**
yThis is displayed when the control box becomes abnormally hot. (Three-phase
high-voltage specifications only)
Check that there are no problems with the cooling fan.
If there is a problem, replace the cooling fan.
**
**
yThe settings in “Setting method for standard depression stroke” may be incorrect.
Redo the settings in “Setting method for standard depression stroke”.
yProblem with treadle unit.
Replace the treadle unit.
S-7220B
*
**
64
14. TROUBLESHOOTING
Error code
Err
21
(Thermistor error)
Possible cause
Page
yIs connector CN16 inside the control box
disconnected?
Insert the connector securely.
*
3159M
Err 100
(GrEASEUP)
yThis appears on the display when the sewing machine has continued to be used for
a certain period after the “GrEASEUP” notification appears without the grease being
applied (without the reset procedure being carried out).
Apply grease and then carry out the reset procedure.
Err 101
(diP SW4)
yIs DIP switch No.4 inside the control box set
to ON?
Set DIP switch No.4 to OFF.
42*
*
3160M
If an error code that is not listed above appears or if carrying out the specified remedy does not solve
the problem, contact the place of purchase.
65
S-7220B
14. TROUBLESHOOTING
(Error code)
If an error code is displayed on the control box panel
1. Make a note of the error code and then turn off the power.
2. After the display of the control box panel turns off, eliminate the cause of the error and
then turn the power switch back on.
3161M
yItems with a “ * ” in the “Page” column should only be checked by a qualified technician.
yFor items with “ ** ” appearing in the “Page” column, ask the place of purchase for advice.
Error code
Possible cause
Page
-0
yIf you continue to use the sewing machine for a certain length of time without applying
grease (and without carrying out the reset operation) after “GU” has appeared on the
control box panel, this will be displayed.
Apply grease and then carry out the reset procedure.
44*
(Grease up)
yIs DIP switch No.4 inside the control box set to
ON?
Set DIP switch No.4 to OFF.
*
-1
(Dip switch 4)
3160M
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
18
19
20
21
Overvoltage
Overcurrent
Encoder error
Motor lock
Safety switch operated
Voltage drop
Panel communication error
Over time
Motor overheating abnormally
Solenoid overcurrent
Refer to pages 62-65 for the items corresponding to
these error codes.
Problem with motor overheating sensor
Solenoid power supply error
Treadle unit error
Head detector unit error
Problem with sewing machine motor operation
Thread trimming solenoid timeout
EEROM error
Control box overheating
Treadle pedal position error
Thermistor error
If an error code that is not listed above appears or if carrying out the specified remedy does not solve
the problem, contact the place of purchase.
S-7220B
66
INSTRUCTION MANUAL
http://www.brother.com/
15-1, Naeshiro-cho, Mizuho-ku, Nagoya 467-8561, Japan. Phone: 81-52-824-2177
© 2006 Brother Industries, Ltd. All Rights Reserved.
S-7220B
SA7437-001 E
2006.06. B (1)