Brother T-8420A, T-8421A, T-8422A, T-8720A, T-8722A Service Manual

T-8420A, 8421A,

8422A

service

manual

T-8720A,

Please

TWIN

NEEDLE

LOCK

8722A

read

this manual before making

STITCHER

any

adjustments.

brother.

This service manual is intended for T-8420A, 8421A,8422A, 8720A, 8722A; be

manual.

Carefully

maintenance.

Asa resultof research and improvements regarding this product, some details ofthismanual may notbe the same as those for

the

Ifyou have

read the

product you

any

"SAFETY

purchased.

questions regarding this product, please contact a Brother dealer.

INSTRUCTIONS"

below

and the

whole

ofthismanualto understandthis

suretoread

the

instruction manual before this

product

beforeyou start

SAFETY

1.

Safety

This service manual and the indicationsand symbols that are used on the machine itself are provided in order to ensure safe

operation of this machine and to prevent accidents and injuryto yourselfor other people.

Indications

A A

Symbols

indications

C

AUIION

0

NO

O

iTirNM

This

indicates

(For example,

This

and

their

meanings

PR

Clx

symbol

the

instructions

and surroundings.

(^)

indicates

natureofthe

the

symbol at left

symbol()indicates

INSTRUCTIONS

which

cause

that

means

foilow

certainly

follow

injury

when

that

mustbetaken.

"beware of injury".)

that

will

almost

could

something

caution

something

this

term

resultindeathorsevere

this

you

indicate

term

indicate

using

the

shouldbecareful

must

not

situations

machineorphysical

do.

injury.

of.

The

where

failuretofollow

where

failuretofollow

damagetoequipment

picture

inside

the

triangle

Q

This

symbol

natureofthe

(For example,

(^)

thing

that

the

symbol at left

indicates

mustbedone.

something

means

that

you

must

"you must make

do.

The

picture

the

ground connection".)

inside

the

circle

indicates

the

T-8400A,

8700A

2.

A

Notes

on

Wait

at least5

opening

safety

minutes

after

thefaceplateofthe

turning

control

off

thepower

box.

Touching

A

DANGER

switch

areas where

CAUTION

and

disconnecting

the

power

high

voltages'are presentcan

cord

from

the

result

wall

outlet

insevere

before

injury.

Environmental

Use the sewing machine in an

from

sources high-frequency welders. Sources problems with correct operation.

Anyfluctuations inthe power supply voltage should

be within ±10% of

Voltage fluctuations cause

problems with correct operation.

The power supply capacity should be greater than the requirements for

o

electrical

Insufficient

problems with correct operation. The

ambient temperature should be within

range of

Temperatures which

may

cause

Machine installation

qualified technician.

0

Contact your Brother electrician for

be

done.

The sewing machine weighs approximately 50 kg.

The

installation shouldbecarried out by two or

more people.

Do not complete. The machine may

0

depressed Turn off the power switch before inserting or

removing the plug, otherwise

box

could

Be

suretoconnect

connection is not

O

receiving a

with

correct

of strong electrical noise

of strong electrical noise may

the

rated voltage for

vyhich

consumption.

power

5®CtoSS'C

problems with correct operation.

connent

by mistake, which could result in injury.

result.

serious

operation

supply capacity

during

are

should

any

electrical work that may

the

power cord until installation is

the

secure,

electric shock, and problems

may

area

are

greaterthan this may

the

sewing machine's

use.

lower or higher than this

onlybecarried

dealer

operate

damage

ground. If

you run a high risk of

also

occur.

which is free

such

as

cause

the

machine.

may

cause

the

Installation

out

by a

or a qualified

need

ifthe treadle is

to the control

the

ground

requirements

The relative

45% to 85% during use, and no

should

Excessively dry or humid environments and dew

formation may

operation.

Avoid exposure to direct sunlight during use.

o

to

Exposure to direct sunlight may

correct operation.

In

and disconnect the power cord from

Lightning may

operation.

All

from any moving parts. Furthermore, do not

excessively bend the cords or

with staples, othenwise there is

0

electric

If using a work table which

should be

move.

Use

tilting

A

only one hand is used,

head

may

Be

handling the lubricating oil

0

do not

inflammation

Furthermore, do not drink under

vomiting

Keep

humidity

occurinany

the

eventofan

cords

shouldbesecuredatleast25mm

shocks

securedinsuch

both

hands

it back or retuming it to its original position. If

may

cause

get

caught.

suretowear

get

into your

can

any

circumstances,

and

diarrhea.

the oil

outofthe

should be within the range of

dew

devices.

cause

electrical

cause

could

to

your

protective

result.

problems with correct

cause

storm,

tum

the

problems with correct

secure

them

the

danger

occur.

has

casters,

a waysothat

hold

the

machine

the

weight of

hand

to slip,

goggles

and

eyes

or onto your skin, otherwise

the

reach

of children.

and

grease,sothat they

oil or

eat

as

they

formation

problems with

off

the

wall outlet.

too

thatfire or

the

they

head

the

your hand

gloves

the

can

power

away

firmly

casters

cannot

when

machine

when

grease

cause

T-8400A,

8700A

A

CAUTION

Sewing

This sewing machine should only be

operators

0

In

safe

The sewing machine should not be

0

applications other than sewing.

Be

machine.

O

Ifgoggles

needle your

Tum off The

A

by

When using a clutch motor,

turning

result of

who

have

received

use

beforehand.

sure

to wear protective goggles when using the

are

breaks,

eyes

and

the

machine may

mistake,

which could

even

the

motor's Inertia. Walt until

not wom,

partsofthe

Injury

power switchatthe

after

there

may

operateIfthe

result

the

power

fullybefore starting work.

•

When

•

When

• When not using

the

machine

Turn off

cleaning.

A

depressed When

using a clutch motor, turning resultof

fullybefore starting work.

Use

tilting It

A

only head

may

even

the

both

back

one

may

get

threading replacing

the

The

by mistake, which could result In injury.

hands

handIsused,

cause

caught.

the

needle

the

bobbin

the

machine and when leaving

unattended

power switch before carrying out

machine

after

motor's Inertia. Walt until

or retuming It to Its original position. If

the

to

your

may

power

hold

the

hand

the

necessary

used

Is the

danger

broken

result.

the

needle

following times.

treadle Is

In Injury.

the

motor

Is switched offasa

the

and

needle

operateIfthe

the

motor will

Is switched offasa

the

machine

weightofthe

to slip,

and

used

by

training

for any

that Ifa

may

enter

depressed

will

keep

motor

stops

Cleaning

treadle Is

keep

motor

stops

head

when

machine

your

hand

If using a work

o

shouldbesecuredInsuchawaysothat

move.

Attach all

machine.

A

devices

Do not touch objects

A

may

machine.

Use

tilting It

A

only

head

may Ifanerror

smells

O

switch. Then

qualified

If

nearest

O

Be

handling

0

do not

Inflammation

Furthermore,donot under

vomiting

Keep

attached. Injury may result.

against

result in

both

back

one

may

get

are

the

machine

Brother

suretowear

get

any

the

table

which

safety

devices

If

the

machine

anyofthe

the

machine while sewing,asthis

personal

hands

to

hold

or retuming Itto its original position. If

handisused,

cause

your hand to slip,

caught.

occursInmachine,orIf

noticed, immediately

contact

technician.

the

lubricating oil

Into

can

circumstances,

and

diarrhea.

oil

outofthe

develops

dealer

protective

your

eyes

result.

your

or a qualified technician.

drink

reach

has

casters,

before using

Is

used

moving

injury or

the

machine

the

weightofthe

abnormal

nearest

a problem, contact your

goggles

and

grease,sothat they

or onto

your

the

oiloreat

as

of children.

the

casters

they

the

sewing

without

partsorpress

damage

head

machine

and

your hand

noises

tum

off the power

Brother

dealer

and

gloves

skin, otherwise

the

they

can

grease

cannot

to the

cause

these

any

when

or

or a

when

Disassembly,

Inspection of

0 O

A

out

carried

Ask

your

carry

out

electrical Tum

off

the cord from othenA/lse depressed When

using a clutch motor,

tuming

resultof

fully before starting work.

Turn off

removing

box

•

When

maintenance

•

When

rotary hook

could

even

the

Maintenance

assembly,

the

sewing

by a qualified technician.

Brother

system.

the

carrying out Inspection, adjustment and

replacing

the

dealer

any

maintenance

power

switch

the

wall outletatthe

machine

by mistake, which could result In Injury.

after

motor's

and

the

power

plug,

result.

may

the

power

Inertia.

consumable

knife

switch

othenvlse

maintenance

machine

or a qualified electrician to

and

operateIfthe

Walt

should only be

and

Inspection of

disconnect

the Is switched offasa

until

parts

before

damagetothe

the

power

following times,

treadle

motor will

the

motor

suchasthe

Inserting or

control

keep

stops

T-8400A,

and

the

and

Is

inspection

Use

both

hands

It

back

or retuming Itto Its original position. Ifonly handIsused, cause

your

hand

caught.

If

the

power

switch

out

some

adjustment,

all

safety

precautions.

Be

careful not to

amount

A

rotary the otherwise

Use

O

Brother.

If absolutely

O

positions

using

Any problems In

0

unauthorized

_covered_bjrttiewamantj^^^

8700A

check

hookorthe

amount

only

the

any

safety

the

of oil supplied to

Injury

proper

sure

and

check

machine.

modificationstothe

to hold

the

weight of to slip,

needstobe

touch

sheet

against

feed

may

replacement

devices

to re-Install

that

machine

the

machine

and

be extremely careful to

your fingers or

moving

mechanism

result.

have

they

operation which resultfrom

head

the

machine

your

hand

leftonwhen

the

parts

when

the

rotary hook,

partsasspecified by

been

removed, be

them

to their original

operate

correctly before

machine

when

tilting

one

head

may

get

carrying

observe

lubrication

suchasthe

checking

will

not

be

III

S.Warning

labels

The following warning labels

Please

difficultto read,

<T-8420A,

followthe instructions on

please

contact your

8720A>

/-

—

1

A ^

A

CAUTION

Movingpartsmay

Operate

Turn

threading, changing bobbin

and

Safety

with safety devices.

off

main

needle, cleaning

devices:

(A) Finger guard (B)

Thread

(C) Beit cover

switch

take-up

cause

cover

appear

injury.

before

etc.

on the sewing machine.

the

labels at all times when using the machine. Ifthe labels

nearest

Brother dealer.

Be

sure

to connect

connection is not secure, you run a high risk of receiving a serious electric shock, and problems with

correct operation may

Direction of operation

the

also

have

been removed or are

ground. If

occur.

the

ground

0

Oil

2955M

pan

2954M

IV

T-8400A,

8700A

2956M

<T-8421A,

f -

1

1A

Hazardous voltage

will

cause

Turn

and

before opening this

cover.

8422A,

A

DANGER

injury.

off

main

switch

wait

Smlnutes

8722A>

A n P

AGEFAHR

Hoclispannung

verletzungsgei^hr!

BItte

schalten

sle

hauptschalter

warten

bevorsiediese

abdeckung

den

aus

sie5minuten,

dffnen.

^ A )b

ADANGER

Unvoltage non adapte

provoque

Eteindre rinterrupteur et

imd

attendre5minutes

d'ouvrir le capoL

des

blessures.

avant

Pa

APELIGRO

Un voltaje Inadecuado

puede

provocar las

herida8.Apagar el

Interrupter principal y

esperar

5 minutos

esta

antes

cublerta.

de

abrir

—^

1

A ^

A

CAUTION

Moving

parts

may

cause

injury.

Operate with safety devices.

Tum

off

main

switch

before

threading, and

changing

bobbin

needle, cleaning etc.

LO

^

secure,

and

Direction of

connect

you

runahigh

problems with correct operation may

operation

Oil

pan

the

ground.Ifthe

riskofreceivingaserious

2867M

ground

also

connection

electric

occur.

Is not

shock,

Safety

devices:

(A)

Finger

(B) Thread

guard

take-up

cover

Control

box

2083M

T-8400A,

8700A

2868M

1.

MACHINE

2.

NOTES

3.

LUBRICATION

Needle

3-1.

rocking mechanism

(minimum lubricationtype) 6

3-2.

Needle

rocking mechanism and

(semi dry type) 7

3-3.

Feed

regulator bushing (both lubrication type) 8

3-4. Rotary hook

minimum lubrication type) 9

3-5.

Feed

lubrication type) 9

4.

ADJUSTMENT

4-1.

Safety

specifications: T-8421A, 8422A, 8722A) 10

4-2.

Thread

spring 11 Thread

4-3.

SPECIFICATIONS

ON

HANDLING

SYSTEM

bar

and

thread

take-up,

and

presser

bar

and

thread take-up,

presser

and

feed rocker

semi

dry

and

minimum

base

(both

semi

bar

(both semi dry

switch position (DD motor

take-up

amount

spring tension 12

and

for

thread

needle

bar

needle

bar bushing

shaft

dry

and

minimum

take-up

CONTENTS

bar

bushing

bar

10

1

5

6

4-10.

Unifying

reverse

stitch lengths for normal feed and

feed

4-11. Rotary hook

4-12.

Clearance

bases

between

23

position 24

rotary hook

and

needle

plate 26

4-13.

4-14.

Clearance

opener

Presser

between

rotary hook

and

27

foot height 27

4-15. Installing thefeed dog 28 4-16. 4-17. 4-18.

4-19.

4-20.

4-21. Replacing the fixed knife

Feed

dog position 28

Feed

dog height 29

Feed

dog angle 30

Tension

Thread

thread

release

trimming timing (Models with

trimmer: T-8422A, 8722A) 32

and

movable knife

31

(Modelswiththread trimmer

T-8422A8722A) 34

4-22. Movable knife position (Models with thread

trimmer. T-8422A, 8722A)

35

4-23. Plate spring (Models with thread trimmer: ^

T-8422A, 8722A) 37

4-4.

Thread

4-5.

Upper

(Under-table motor specifications:

T-8420A, 8720A) 14

4-6.

Upper

(DD

T-8421A, 8422A, 8722A)

4-7.

Needle Needle

4-8.

4-9. Quick

T-8421A, 8422A, 8722A) 22

take-up

shaft

motor

drop and

reverse

amount

and

lower

shaft

timing

and

lower

shaft

timing

specifications:

fonward-back position 17

rotary hook timing

device (DD motorspecifications:

13

15

20

T-8400A,

4-24. Tension

release

trimmer. T-8422A, 8722A) 38

4-25.

Thread

wiper (Models with

T-8422A, 8722A) 39

4-26. Adjusting the needle up 4-27. Adjusting the treadle 41

4-28. Adjusting

4-29.

8700A

amount

Adjusting

(minute

the

lifting

wire (Modelswith thread

thread

stop

position 41

rotary hook lubrication

presser

foot floating

amount)

trimmer

42

amount

43

5.

APPLYING

5-1.

When

the

GREASE

indicator

illuminates

44

(T-8420A, 8720A: Semi dry type) 44

11.

CONTROL

(T-8421A, 8422A,

11-1. Removing

BOX

and

AND

8722A)

installing

MOTOR

the

controi box 76

76

5-2. When "GREASEUP"

8422A, 8722A:

6.

GREASE

LUBRICATION

AND

7.

SWITCHING

TO

8.

REPLACING

APPLICATION

REPLACING

LOWER

WHEN

FROM

FEED

GAUGE

appears

Semi

dry specifications) 47

DISASSEMBLING

PARTS

NEEDLE

(T-8421A,

AND

PARTS

FEED

(CHANGING THE NEEDLE WIDTH)... 55

9.

FUNCTION

SETTINGS

(T-8421A, 8422A, 8722A) 57

9-1. Maximum sewing

sewing

9-2. Using

9-3. Setting

9-4. Setting functions

9-5.

Function

9-6. Clearing

10.

CONTROL

speed

the

LOCK key 58

the

List

saved

speed

setting

DiP

switches

data

SYSTEM

and

start backtack

methods

(Initialization) 74

(T-8421A, 8422A, 8722A) 75

50

53

57

58

59

60

and

11-2. Control box

11

-3.

Control

11-4. Checking 11-5. Checking

12.

TREADLE

circuit

motor rating piate 77

board

the

motor

and

power

the

soienoids

UNIT

ASSEMBLY

supply

(T-8421A, 8422A, 8722A) 83

12-1.

Types

12-2.

Standard

12-3. Setting method for

strokes

13.

STANDING

(T-8421A, 8422A,

13-1. Installing

13-2.

Connectors

14.

TROUBLESHOOTING

14-1.

Sewing

14-2. Error

(T-8421A. 8422A, 8722A) 101

setting

OPERATION

the

code

displays

values

standard

depression

PEDAL

8722A)

foot plug 87

79

81 82

83 84

85

87

88

89

'P8400A,

8700A

1.

MACHINE

1.

<

Model

SPECIFICATIONS

MACHINE

plate

Indications

SPECIFICATIONS

>

BROTHER

•

T-8421A-T03

T T

INDUSTRIES,

LTD.

•

TTT

J

A

B

C

—______

Rotary

"

Thread

Quick

Thread

D

Lubrication

E

<

Listofmodels

standard

With

thread

Thread

Use

hook

trimmer

hook

trimmer

reverse

wiper

-

tvpe

and

specifications

A B

4

Standard

0 1

0

-

Minimum

F

For

foundation

hook

-

0

lubrication

>

Motor

DD

motor

T-8422A

For

medium-

ODE

4

O

3

light-weight

weight

Lubrication

(Dryr Semi

dry

-030

Minimum

-OOO

and

materials

lubrication

type

7

Large

hook

2

O

T

O

—

3

Semi

dry

5

For heavy-weight materials

Use

(-003)

-003. (-005)

-003.

-005

Without

thread

trimmer

Large hook

I

Thread

With

thread

Without

( )

Itis available from local

thread

types

trimmer

are

not included in

dealers

DD

motor

T-8421A

Under-table

T-8420A

DD

motor

T-8422A

Under-table T-8420A

the

specification lineup.

by special

order

motor

Motor

motor

or by installing optional parts.

T-8400A,

8700A

(Dry)*

Semi

-030

Minimum

-OOO

(Dry)*

Semi

-030

Minimum

-OOO

Lubrication

Minimum

-OOO

Minimum

-OOO

dry

lubrication

type

lubrication

(-003.-OOF)

-OOF.-003. (-005)

(-00F).-003.-005

(-003.-OOF)

-OOF.-003. (-005)

-OOF.-003.-005

Use

-003.

-DOS

-003.

-005

<

Drive

Installation position

Type

Control

<

Gauge

motor

circuit

part

>

Built

AC

Microprocessor

widths

DD

motor

into

servo

machine

motor

head

(4-oole,

550W)

(compatibility with

bed

Installed

(obtained

Clutch

and

Under-table

under

locally)

motor,

rotary

etc.

hook

Refer to the parts book forthe availabilityofgauge parts for various specifications.

T-8420A.

T-8422A T-8720A T-8722A

Model

8421A

Standard

1.6-38.1

bed

mm

Special

Max.77mm Max.45mm

Max.68mm Max.45mm

table

-

motor

order

1.

MACHINE

base)

SPECIFICATIONS

>

T-8400A,

8700A

1.

MACHINE

<

Specifications

SPECIFICATIONS

>

T-8420A

T-8421A

Use

Max.

Start

backtacking

End

Max.

Presser

Feed

Thread

Needle

Presser

Rotary

Needle

(Standard

sewing

backtacking

stitch

foot

dog

height

take-up

bar

foot

hook

DP

(Standard/Organ)

Feed

mechanism

Arm

pocket

Weight

speed

length

height

stroke

pressure

x 5

width

speed

stroke

hook,

hook.

(Dry)

Semi

Minimum

lubrication

and

Lifting

Knee

T-8420A

T-8421A

Without

dry

continuous

lever

lifter

thread

trimmer,

-nnF

For

foundation

7.5-58.5

#11

(#9-#14)

Under-table

DP

motor)

3,000

4,000

51.9

Thread

take-up

N

Horizontal rotary

Needle

motor)

-nn3

For

light-weight

medium-

rpm

250

- 1,800 rpm (T-8421A only)

1,000

rpm

4

mm

lever

Standard

feed/Lower

120

weight

materials

3,000

rpm

(T-8421A

7

mm

13

mm

1

mm

No.3

33.4

mm

hook

#14

(#11-#16)

feed

x264

42.5

46.5

hook

kg

and

only)

Thread

10-78N

(vertical axis)

(Canbeswitched)

mm

-nn5

For

heavy-weight

materials

3,000

5

56.8

take-up

No.5

#22

(#14-#22)

-

rpm

mm

lever

T-8422A

Use

Max.

Start

(Standard

sewing

backtacking and continuous

backtacking End

backtacking

Max.

stitch

Presser

Feed

Thread

Needle

Presser

Rotary

Needle

(Standard/Organ)

Feed

Arm Weight

foot height

dog

height

take-up

bar

foot

hook

DP

mechanism

pocket

speed

length

stroke

pressure

x 5

width

speed

stroke

hook.

(Dry)

Semi

Minimum lubrication

Lifting

Knee

With

dry

lever

lifter

thread

trimmer,

medium-

DD

motor)

-nn3

For light-weight

weight

3,000

4,000

materials

rpm

and

3,000

rpm

250-1,800

1,000

rpm

4 mm 1 5

7

mm

13

mm

1

mm

51.9

mm

(#11

Thread

Horizontal rotary

#14

-#16)

Needle

feed/Lower

take-up

33.4

10-78

Standard

120x264

49.5

lever

mm

hook

feed

kg

For

heavy-weight materials

3,000

rpm

No.3

N

(vertical axis)

(#14-#22)

(Canbeswitched)

mm

-nn5

-

rpm

mm

#22

T-8400A,

8700A

1.

MACHINE

SPECIFICATIONS

T-8720A (Large

T-8722A

Use

Max.

speed

Start backtacking

backtacking

End Max.

Presser

height

Feed

Thread

Needle

Presser

Rotary

Needle

(Standard/Organ)

Feed

Arm

Weight

(Large

sewing

speed

backtacking

stitch

length

dog

height

take-up

bar

stroke

foot

pressure

hook

DP

mechanism

pocket

width

foot

x 5

hook

speed

stroke

• Without

• With

Minimum

lubrication

and

Lifting

Knee

lifter

T-8720A

T-8722A

thread

continuous

lever

thread

trimmer, DP

trimmer, Under-table motor)

motor)

-nns

For light-weight

medium-

weight

(#11

#14

and

materials

250-1,800

1,000

Thread

Horizontal rotary

-#16)

Needle

feed/Lower

3,000 rpm

rpm (T-8722A only)

rpm(T-8722A

7

mm

7

mm

13

mm

1

mm

62.4

mm

take-up

10-78

Large

120X264

33.4

42.5

49.5

lever

mm

N

hook

(vertical axis)

hook

feed

(Canbeswitched)

mm

kg

-nns

For

heavy-weight materials

only)

No.6

#22

(#14-#22)

T-8400A,

8700A

2.

NOTES

ON

HANDLING

NOTES

ON

HANDLING

About

the

• Do not

such

machine

set

as

set-up

up this sewing machine

televisions,

location

radios

or

near

other

cordless

otherwise such equipment may be affected by electronic

interference from

the

sewing

machine.

• The sewing machine should be plugged directly intoan AC

wall outlet. Operation problems may result if extension

cords

are

used.

Carrying

the

•

The

as

showninthe

<T-8420A,

Make

<T-8421A,

Hold

does

machine

machine should be carried by the arm by two

illustration.

8720A>

sure

that

the

not

8422A,

motor

rotate.

machine

8722A>

cover

(A) by hand alsosothat

pulley

does

equipment

telephones,

people

not

tum.

the

pulley

<T.8420A.

<T-8421A.8422A.

8720A>

8722A

2086M

2959M

>

Tilting

back

• Hold

move,

the

Returning

1.

Clear

holes.

2. While holding

retum

right

the

section

and

machine

the

away

the

hand.

machine

(B) with

then

push

head.

machine

any

tools,

the

machine

head

your

footsothat

the

arm

headtothe

etc.

which

face

plate

headtothe

the

table

with both

with

upright position with

hands

upright

maybenear

your

left

hand,

position

does

to tilt

the

o

2870M

not

back

2871M

table

gently

your

2872M

T-8400A,

8700A

3.

LUBRICATION

SYSTEM

3.

LUBRICATION

SYSTEM

3-1.

Thread

mechanism

Needle

presser

take-up

bar

and

thread

bushing

take-up,

(minimum

Oil

terminal

needle

lubrication

Oil

tank

bar

rocking

type)

mechanism

(2) Two

and

[G]Lubrication points requiring

(1)Wick

(2)

Felt

Presser

bar

bush

r

grease

[Q]

Folded

(2)

over

twice

po

go

(1) Two

Oil recovery•

from

jaw

-[Gl

Needle

bearing

D I I

-Jl

I-

[Q]

[01-

3007M

:i

rw

n

L'

y

T-8400A,

8700A

3008M

3.

LUBRICATION

SYSTEM

3-2.

Needle

presser

[G] Lubrication points requiring

i:|>

(1)to (7)requiregrease application.

(8) Wick

bar

(2)ci>|

and

thread

bushing

grease

take-up,

(semi

dry

.btd

(8) [Grease applied]

[TWn

o

C<;3(7)

needle

type)

[G]

1^:'

„

If

bar

I r

1 L

rocking

[0]

mechanism

and

Thread

take-up

[Gl

mechanism

[Gl

Presser

bar

(6)

bush

0

i:[>o

[0]

[01-

D

O

-[01

T-8400A,

8700A

3009M

3010M

3.

LUBRICATION

SYSTEM

3-3.

Feed

minimum

The

lubricating oil inside

Topofbed

regulator

lubrication

the

oil

coverisused

and

feed

rocker

type)

for lubricating

these

shaft

parts.

bushing

[G] Lubrication

(1)to(7) (8) Felt

A

Felt

(both

Wick

points

semi

requiring

grease

dry

and

Needle

bearing

Feed

regulator

Felt

Feed

regulator

(3) (4)

Felt

A

(5) (6)

(4) (3)

Oil

cover

T-8400A,

8700A

301IM

8

3.

LUBRICATION

SYSTEM

3-4.

(1)Wick (2)

<

Rotary

Felt

<Left

side>

Same

as

right side >

hook

base

(both

semi

<Rlght

Needle

side>

beanng

(1)

dry

and

minimum iubrication type)

Oil

tank

Air bleeding

3-5.

(1)Wick

(2 Felt

Feed

bar

(both

semi

dry

and

minimum lubrication type)

Feed

bar

3012M

©

3098M

T-8400A,

8700A

4.

ADJUSTMENT

Disassembly,

of

0

O

A

the

a qualified technician. Ask

your

carry out any

electrical

If

any

absolutely positions and

before using

Use

both

tilting it back or returning it to its original position. If

only

one

head

may

get

assembly,

sewing machine should only be

Brother

maintenance

system.

safety

devices

sure

to re-install

check

the

machine.

hands

handisused,

cause

caught.

maintenance

dealerora qualified electrician to

and

inspection of

have

been

them

that

they

operate

to

hold

the

machine

the

weightofthe

your

hand

to slip,

to their original

A

and

inspection

earned

removed,

head

and

your

CAUTION

out by

correctly

when

machine

the

be

hand

A

Tum

off

the

power

cord from

otherwise depressed When turning

result

stops

•

When

maintenance

•

When rotary

the

If

out observe

the

wall outletatthe

the

machine may

by mistake, which could result in injury.

using a clutch motor,

even

after

of

the

motor's

fully before starting work.

carrying out inspection,

replacing

hook

and

power

switch

some

adjustment, be extremely careful to

all

safety

switch

and

the

power

inertia.

consumable

knife

needstobe

precautions.

4.

ADJUSTMENT

disconnect

operateifthe

the

is switched offasa

Wait

parts

leftonwhen

the

following times,

treadle is

motor

will

until

the

adjustment

suchasthe

carrying

power

keep

motor

and

4-1.

Safety

(DD

Machine

motor

If

the

spring operating

the

safety

(2)

bed

switch

position

specifications:

strokeistoo

switch will

not

1.5mm

operate.

-T-

short,

Table

(A)

4.5mm

T-8421A, 8422A, 8722A)

The

(B)

standard

showninthe

At

the

adjusted

readjusted.

However,ifthe

the

gap

or narrower

adverse

happens,

* If the operation of

way,

depressed.

<

Adjustment

1.

Loosen

2. Move position

and

3. Tighten

installation position for

illustrationatleft.

time of shipment from the factory, dimension (A) is

to 3 mm,

between

than

effect on

adjustasfollows.

the

sewing

and

dimensionsofthe

the

machine

the

standard

the

operation of

the

machine

method

the

screw

(2).

the

safety switch (1) to

so

that

screw

the

(2).

the

tableis4.5

the

safety

switch (1) is

normally this

bed

gap

safety switch (1) is affected in this

will

does

work

table

and

the

safety

start

table

when

(1.5 mm), it may

the

not

needtobe

makeitso

hole is wider

switch (1). Ifthis

the

treadle is

>

the

gap

mm.

(B)

left or right to adjust its

between

the

safety switch (1)

have

that

an

3013M

T-8400A,

8700A

10

4.

ADJUSTMENT

4-2.

<

Measurement

Thread

take-up

method

amount

>

Pass

thread

upper

take-up

for

thread

3014M

through

take-up

The

standard

springs R (1) and L (2) Is 7 mm.

take-up [right](3)

standard

The stopper

stud

(5).

<

Adjustment

The

thread

decreases

Heightofstopper

spring

amounts

and

the

[left] (4)

take-up

when

thread

take-up

by changing

stopper[left](4). heights of

are

when

method

the

>

amount

height of

[right] (3)

length for

You

can adjust the thread

the

heights of the

the

stopper

the

are

for a

the

stopperIsIncreased.

[for

right

[right] (3)

aligned with the tension

thread

thread]

thread

take-up spring

1. Loosen the screw (6), and then slide the stopper

to

adjust

the

thread

2. Tighten

the

screw

take-up

(6).

amount.

take-up

stopper

and

[right]

the

(3)

Heightofstopper

1. Loosen

to

2. Tighten

the

adjust

the

screw

thread

screw

[ieft] (4) [for ieft

(7),

and

then

take-up

(7).

amount.

thread]

slide

the

stopper

[left] (4)

0

3015M

Note:

35mmormore

-Pull

If using a

length for

thread trimming

The 35 mm the

take-up

However, if using fine

thread

much

or it might result in thread trimming errors for

thread.

thread

the

trimming

left upper

thread

becauseofthe

trailing length is normal if

when

the

thread

amount

or finer), reducing

may

thread is pulled from

length is

shorter

of the thread take-up spring.

threads

cause

the

right

the

upper

sewing

may

twist In

the

upper

than

this,

(suchas#50

thread

threadtobe

machine,

become

the

thread.

thread

the

needle

reduce

take-up

the

shorter

length Is

the

polyester

amount

cut

too

the

left

trailing

after

hole. If

thread

too

short,

upper

Trailing

thread

3016M

11

T-8400A,

8700A

4.

ADJUSTMENT

4-3.

<

Measurement

Thread

take-up

method

>

Do not thread

Upper

measuring thread

amount

0

spring

pass

take-up

limit position

Stronger

tension

thread

Weaker

Stronger

through

when

take-up

Weaker

The standard tensions forthe thread take-up spring R (1) and thread take-up spring L (2) are as

sewing

<

Thread

1. Loosen

2. Tighten

Thread

1.

2. Use a small screwdriver to turn

3. Tighten

machine

For

foundation

For light-weight

(-nn3)

For

heavy-weight

Adjustment

take-up

the

set

to

adjust

the

tension.

the

set

take-up

Loosen

adjust

the

tension

tension.

tension

specifications.

(-firiF)

and

medium-weight materials

materials

method

spring

screw

spring

>

R (1) [for

(3), and turn

(3).

L (2) [for left

nut

(5).

nut (5).

(-flflS)

right

follows

the

thread]

the

depending on

0.25N

0.35N

0.70N

thread]

adjusting thumb (4)

tension

stud

(6) to

3017M

T-8400A,

8700A

12

4.

ADJUSTMENT

4-4.

<For

non-foundation

Do not

thread through.

<For

foundation

Pass

the

through.

Thread

pass

the

thread

take-up

speciflcatlons>

speclficatlons>

amount

(1)

Center

2928M

The thread take-up amount is adjusted by how the thread Is

passed

<

For

Do not

through the thread amount adjuster (1).

Using

the

standard

non-foundation

pass

the

thread through

thread

specifications

amount

the

adjuster

(1) >

thread amount adjuster

(1). Loosen the screw (2) and slide the thread amount

adjuster (1) to

For

foundation

Pass

the thread through the thread

the

right-side position.

specifications

amount

adjuster (1).

The standard position of the thread amount adjuster (1) is

when the

<

Adjusting

When the thread

amount adjuster (1),

less

right.

It is

amount

•

screw

(2) is in

the

when

the

thread amount

better

When with foundation specifications

When

when

nottopass

adjuster

sewing

the

thread

the

stitch length is

thread

has

(1):

heavy

take-up

the

been

the

materials

take-up

thread

the

increased

centerofthe

amountisnot

adjustment range.

amount

passed

through the thread

take-up

adjuster

thread

(1) is moved to

through

usingasewing

>

amount

enough,

becomes

the

thread

machine

such

the

as

Thread

amount

take-up

is too large

(3)-

(B) *— Thread take-up

amountIstoo

Startofmovement

2929M

3018M

small

It is

bettertopass

adjuster

(1);

• When sewing with slippery

yams

the

thread

through

threads

the

such

thread

as

amount

synthetic

• When sewing light materials

• When sewing with a stitch length of 2 mm or

• When sewing

you would like to prevent

tightening problems

<

Guidetoadjustment

The

standard

tension spring (3)

under

thread

starts

anyofthe

above

skipped

suchaslooping, or thread

>

take-up

amountiswhen

to move

when

the

less

three

conditions

stitches,

breakages

the

loop is moved to

and

thread

point (B)which is slightly in front of point (A)where the rotary hook tip catches the upper thread loop and the rotary hook

thread

amountisat

its

maximum.

• If the thread take-up amount is too large, the thread

tension spring (3)

(A) is

passed.

This can

tightening

• If

the

thread

take-up spring (3)

This

can

the

upper

The thread take-up amount required

the

typeofthread,

length,

sewing

so

adjust

conditions.

will

not start to move

cause

and

take-up

cause

thread

the

skipped stitches, poor thread

thread

breakages.

amountistoo

will

start moving before point (B).

thread

breakages,

and

pulling of

thicknessofthe

thread take-up

even

after point

small,

the

overtightening of

the

seam.

will

vary depending on

material

amount

and

to suit the

the

thread

stitch

3019M

13

T-8400A,

8700A

4.

ADJUSTMENT

4-5.

Upper

shaft

(Under-table

and

motor

lower

shaft

timing

specifications: T-8420A, 8720A)

3020M

Remove

Tilt

Remove (Gradually slide

turning

4.

Place

the mark (3) on timing pulley D (2)is aligned with

reference line (4) when

position.

(Place

gradually slide the timing belt (1) to the left while turning

the

back

machine

needle.

the

machine

the

timing belt (1).

the

machine pulley fonvard.)

the

timing belt (1) onto timing pulley D (2)sothat

the

timing belt (1) part of

pulley.)

head.

the

timing belt (1) to the right while

the

thread take-up is at its highest

the

way on

the

and

bed

then

When

the

highest

When

highest position

thread

position

the

needle

take-upisat

barisat

3021M

its

3022M

<

Adjustment

method

>

1. Check that the mark (3) on timing pulley D (2)is aligned withthe bed reference line (4) when the thread take-up is

at its

highest

Also at this time,

position.

check

that

the

<A> mark on

the

machine

pulley is visible in about the middle of the belt cover

window.

2. Check that

In

about

needle

3.

Install

the

barisat

the

needle.

the

<->

mark on

middleofthe

Its

highest

the

machine pulley is visible

belt

cover

window

position.

when

the

T-8400A,

8700A

14

4.

ADJUSTMENT

4-6.

Upper

(DD

shaft

and

lower

shaft

timing

motor specifications: T-8421A, 8422A,

3023M

3024M

8722A)

<

Before

Check that the index mark (1) on the machine pulley and the

index mark (2) on the pulley holder

* Ifthe index marks (1) and (2)

screws (3)and alignthe index marks (1) and (2).

<

Adjustment

1.

2.

Tilt

3. Remove the retaining ring (4)

and

4. Remove the screw (7), (The screw (7) into

table.)

5.

Remove

back

the

Remove

adjusting

>

method

the

needle.

the

machine

washer

(6).

canbeloosened

cut-away part in

the

quick

reverse

>

head.

and

are

aligned.

are

not aligned, loosen the

and

then remove the pin (5)

loosen

the

screw

by inserting a screwdriver

the

oil

pan

(9) underneath

solenoid

(10).

(8).

the

3025M

6. Remove the timing belt (11).

15

3026M

T-8400A,

(Gradually slide

tuming

the

8700A

the

timing belt (11) to

machine pulley forward.)

the

right while

E-

When

at its

When

its

highest

the

highest

the

thread

position

needle

position

take-up

barisat

is

3027M

4.

ADJUSTMENT

7. Place the timing belt (11) onto timing pulley D (12)sothat

the mark (13) on timing pulley D (12) is aligned with

the

bed reference line (14) when the thread take-up Is at Its

highest

(Place gradually slide the timing belt (11) to

the

<

Adjustment

1.

Check

with

position.

the

machine

that

the

bed

timing belt (11) part of

the

way on

the

left while turning

pulley.)

method

the

mark (13) on timing pulley D (12)ls aligned

reference line (14) when

>

the

thread take-up Is

and

then

at Itshighest position.

Alsoatthis

pulley Is visible In

window.

2.

Check

in

about

needle

3. Install

4.

Install

that

the

barIsat

the

quick

the

needle.

time,

check

the

<->

middleofthe

Its

highest

reverse

that

the

about

the

markonthe

belt

position.

solenoid (10).

<A>

markonthe

middle of

machine

cover

machine

the

belt

pulley Is visible

window

when

cover

the

3028M

Note:

When assembling the jointunit (15) after Ithas been disassembled,

aligned withthe center of

Sewing

machine

operating

direction

the

screw

(16) at

the

front.

T-8400A,

8700A

Install

so that the mark (18) on

timing

Securely

pulley

tighten

U (17) Is

3029M

16

4.

ADJUSTMENT

4-7.

ep

Needle

r-(4)

drop

forward-back

13.3-13.7mm

(7)-

position

3030M

3031M

<

Checking

1.

Set

2. Move

3. The

method

the

stitch length dial to "0".

the

needle

gap

between the needle

bar

>

(1) to its lowest position.

bar

(1) and

(3) should be 13.3-13.7 mm at the bottom

presser

If

adjustmentisnecessary,

<

Adjustment

1.

Remove

cover

2.

Loosen

3. Move

between

13.3-13.7

above.

4. Tighten

5.

Check (This is

bolt (6) is tightened.)

6. Install

7.

Check hole in (The

goes

whenitcomes

The * If

(5).

the

needle

into

needle

the

"4-16.

bar

bush

(2).

method

the

seven

the

bolt (6).

needle

the

needle

mm

the

bolt (6).

once

more thatthe

because

the

rear

that

cover

the

feed

will actuallybeslightly to

the

feed

out.)

screws

bar

as

the

needle

dog

>

(1)

bar

described

needle

(5).

goes

(7).

(7),

should not be touching

needle

touches

Feed

dog position").

follow

the

procedure

(4)

and

then

fonA^ardorbacksothat

(1)

and

the

in <Checking method>

gapis13.3-13.7

bar

(1) may move when the

into

the

and

will

be slightly to

the

feed dog, check

the

remove

presser

mm.

middle of

the

feed

dog

presser

edge

below.

bar

the

front

(7).

the

needle

when

the

steps

bar

of the

rear

gap

(3) is

it

back

in

Touchesiftoo

small

n n

=®

Touches

Iftoo

3032M

large

3033M

<

Reference

If

distance

•

The

feed

>

(A) Is

dog (7)

too

large

will

touch

the

needle

when

the

stitch

length dial is at the maximum setting

• Skipped stitches and needle

breakages

may occur.

• Lower thread trimming errors at the right side and upper

thread

If

distance

•

The

trimming errors at

(A) is

too

feed

dog (7) will touch

small

the

left

the

side

needle

may

occur.

when

the

stitch

length dial is at the maximum setting.

• Skipped stitches and needle breakages may occur.

• Lower thread trimming errors at

the

left

side

and

upper

thread trimming errors at the right side may occur.

17

T-8400A,

8700A

4.

ADJUSTMENT

(2)

r-(B)

^(9)

n""

3034M

3035M

Note:

When

adjusting

not

move

arm

(3) with

Ifthey

are

various when

RealignmentIfthese

1.

mechanisms,

changing to lower feed.

Set

the

2. Tighten

the

feed

3. Move bolt (5) from (B) to (C).

(Be careful not to pull bolt (5)

washer

4. Check that

the

presser

(If

gap

drop forward-back position" on

5. Move bolt (5) from (C)

(Be careful not to pull bolt (5)

washer

6.

Check

(7)

and

If

gap

1)

Loosen

2) Tum

(A)

(8) to

the

needle

the

feed

rocker

respecttothe

arm

feed

moved, they may

and

the

parts

are

stitch length dial to "0".

the

screw

(4) to

secure

rocker

shaft

(1).

(6)

may

fall down.)

the

gap

(A) between

bar

(8) is

13.3-13.7

(A) is incorrect, adjust while referring to "Needle

back

(6)

may

fall down.)

once

more

that

the

(A) Is

between

presser

Incorrect:

the

13.3-13.7

bar

screw

needle

the

(8)

(9).

bar

needle

mm.

3) Tighten the screw (9).

(Be careful not to move the needle bar rock arm (3) sideways at this time. If it is moved sideways, the

needle

bar rocker link (10) may move out of

alignment. Refer to "Needle

sideways position" on the

4) Check once more that the

needle bar (7) and

mm.

the

drop

forward-back position, do

(2)

and

the

rocker

cause

interference between the

needle

accidentally

the

out

the

mm.

the

needle

shaft

(1).

drop

position may shift

moved

feed rocker arm (2) to

too

far, othenA/ise

needle

page.)

to (B).

out

too

far, otherwise the

gap

(A)

is13.^13.7

between

mm.

the

needle

rock arm (3) to adjust the

bar

(7)

and

the

presser

bar

following

presser

gap

bar

rocker link

page

for details.)

(A) between the

(8) is 13.3-13.7

bar

rock

(7) and

the

bar

gap

bar

(8)

Do not fully bolt (5)sothis

fail

down.

(A)

13.3-13.7mm

(11)

remove

does

the not

3036M

7. Check that

hole in

Ifthe

the

needle

the

feed

touches

needle

dog (11).

the

goes

into the middle of the needle

feed dog (11), adjust

the

of the feed dog (11) to match the needle position. (Refer

to "4-16.

Feed

dog position".)

position

T-8400A,

8700A

18

4.

ADJUSTMENT

Needle

bar

rocker

f

link

sideways

s

position

§

A small *

These

* Ifno

feed

shaft

gap

(0-1

gaps

are clearance shaft

(1)

(1).

3037M

mm) is

necessary

determined by

(0-1

mm)

are

installed flush, you will

the

canbeobtained

Installthe needle bar rocker arm (3)sothat Itis flush with the

feed

rocker

shaft

(1).

* Refer to the

the

needle

on both

sides.

sideways

even

needtoadjust

following

bar

position of

though the

to check

rocker link (10).

the

needle

bar

needle

bar

the

sideways

the

sideways position of

rocker

arm

(3).

rock

arm

(3)

position of

the

and

the

feed

Gapisalmost

0 mm.

3038M

19

T-8400A,

8700A

4.

ADJUSTMENT

4-8.

(4)-

Needle

and

rotary

(A)=

hook

timing

1.

Set

the

stitch length dial to

tobesewn.

Standard

2. Remove

3. Loosen

stitch length

Specifications

-nnF

-nn3

-nns

the

rubber

the

screw

down to adjustsothat

needle

lowest position.

bar

(2) Is aligned with

bar

bracket (4) when

(Be careful not to

4. Securely tighten

5. At this time,

and

the

same

as

the

front of

each

other.

(5)

tum the gaps

the

cap

and

the

screw

(A)

feed

the

actual length of

(1).

move

the

top

the

needle

(5).

and

(B)

dog

stitch

length

the

needle

reference

the

bottom

needle

bar

(2)atthis time.)

between

(7)

should

the

stitches

dial

2 2

3

bar

(2) up or

line (3) on the

edgeofthe

bar

(2) Is at Its

the

needle

be

about

(6)

the

Needle

2.4mm

bar

lowest position

T

(3)

12mm

(A) = (B)

3039M

6. Tum the machine pulley forward to

(2) until

the

reference line ((8) or (9), depending on the

raise

the needle bar

feed condition) on the needle bar (2) Is aligned with the

bottom

edgeofthe

7. In this condition, similar,sothat

The procedure up to this point determines

amount.

Note:

If

the

• It

needle

will

bar

cause

• Both the left and right skipped stitches or thread

•

Upper

thread

needle

bar

secure

the

lift

the

needle

bar

amountistoo

poor tightening In

seams

breakages

trimming

errors

base

(4).

machine

pulley with

(2) will not move.

the

large

the

right thread.

will

become

willoccur.

may

occur,orthe

needle bar

uneven, and

thread may be cut too short (models with thread trimmer).

will

• The upper thread trailing length

with

thread

trimmer).

be too long (models

tape

upper

or

lift

Lower

feed

Needle

feed

3040M

T-8400A,

needle

• Skipped stitches

• The upper thread trailing length

with

8700A

thread

bar

lift

trimmer).

amount

and

thread

Is

too

breakages

If

the

small

will

occur.

willbetoo short (models

20

4.

ADJUSTMENT

(11) (12)

(13)

—(10)

3041M

8. Loosen the

base

(The removed from the rotary hook

(12) to prevent

9. Loosen

cover

screws

the

screws

FL (11)

(10), and then remove rotary hook

and

FR (12).

(10) is designed

them

from being lost.)

set

screws

(13) (three

so

that they cannot be

base

cover FL (11)

each

at left

and

(However, be careful not to loosen them too much,

othenvise of

the

able amount

the

set

rotary hook

to turn.

which will still allow

screws

base

Loosen

(13)

will

touch

and the pinion

the

set

screws

the

gear

by

rotary

inside surface

(14)

will

the

minimum

hooktomove

freely.)

10. Tum

11. Tighten

12.

the

rotary hook by hand to align

(15) with

the

machine pulley

the

set

(Tighten the

three

ordersothat

tilted.)

Remove

the

tape

the

rotary hook tip

middle of the needle. (Do not turn the

at

this time.)

screws

the

(13).

set

screws (13) a little bit at a time in

pinion

gear

(14)

does

not

that

is securing

the

machine

pulley.

and

FR

right).

not be

become

Color

Needle

lowest position

bar

In

Mark

Mark /

(I

(C)

1-1.5mm

(C)

3042M

3043M

13.

Useanoil-based

needle.

14. With

the

needle

while pushing with

your

finger to

(15) in

the

hollow of

15. Check that between center

holeis1-1.5

* If

the

line of

the

distance is not

again

and

* If dimension

reference by

the

If

usingathread

not

easily

bottom

needle

problem.

form

• If problems

breakages

mm to

the

Note:

•

When

upper

occur,

makeiteasier

thread

the

stitch length is

change,sore-check

• During quick

needle

will

become

0.7 mm, otherwise projection (D)

(15).

marker

raised, tum

the

pen

needle

against

makeamark

the

needle.

distance

(0)

to color in

the

machine pulley fonvard

the

rotary hook tip (15)

from

the

rotary hook tip

from

the

mark from the rotary hook tip (15)

the

needle to

mm.

adjust

(0)

line (3) on

edgeofthe

barisat

such

stable

such

as

set

the

loops

the

top

edgeofthe

1-1.5

height of

has

the

its

lowest

as

polyester

mm, loosen

the

been

adjusted,

needle

bar

needle

position, but this is

the

needle

(2)

maybehidden

bar

base

thread

skipped stitches or upper thread

the

above

distance (C) to

for the rotary hook tip (15) to

loop.

reverse

and

changed,

distance

operation, distance (C) for the left

shorter,sodo

the

rotary hook tip (15) may touch the

this could

distance

(0)atsuch

not

damage

times.

set

it to

the rotary hook tip

hollow of

intersection

and

needle

screw

bar.

the

highest

(4)

when

which

0.7-0.8

catch

(C) will

less

the

(15)

not

does

also

than

a

0.7-0.8mm

3044M

21

T-8400A,

8700A

4.

ADJUSTMENT

4-9.

Quick

reverse

device

(DD

motor

3045M

specifications:

1.

Set

the

stitch length dial 1/2 a

setting.

(For

example,ifthe

length dial to 3.5.)

2.

Tilt

back

the

machine

3.

Loosen

(The into

table.)

4. When

solenoid bracket (7)sothat

quick

then

* If

the

screw

the

cut-away part in

the

reverse

tighten

the

gap

quick

reverse

screws

(2) can be loosened by inserting a screwdriver

reverse lever (4) is fully lowered, move the

solenoid (5)

the

mentioned

T-8421A, 8422A, 8722A)

step

below

the

maximum

maximum setting is 4,

head.

(1)

and

(2).

the

oil

there

and

the

screw

(1).

aboveistoo

solenoid (5) will

pan

is no

rubber

large,

become

set

the

(3) underneath the

gap

between

stopper

the

operation

sluggish.)

(6),

stitch

the

and

of

3046M

3047M

T-8400A,

8700A

22

4.

ADJUSTMENT

4-1

0.

Unifying

stitch

lengths

for normai

feed

and

reverse

feed

11

Normal

stitches

feed

I

Reverse

feed

1822M

3048M

The following explains how to make the stitch lengths the

same

for

normal

feed

and

1.

Set

the

stitch length dial to the actual stitch length that is

tobesewn.

Standard

T-8420A

T-8421A T-8422A

T-8720A T-8722A

2. Turn machine

feed

stitch

Model

the

machine pulley by

at low

and

reverse

3. Ifadjustment is

1)

Remove

2) Loosen

3) Turn

degrees

the

to adjust.

(If you turn

the

adjustment

The

standard

the

eccentric

- If

the

than

for

Tum

lengths

-DDF

-DD3.

-DD3.-DD5

speed

feed

necessary,

the

rear

set

eccentric

the

position is

shaft

stitch

reverse

the

reverse

Specifications

-DD5

(11

cover.

screw

eccentric

will be

(2) is aligned with the

lengthIslonger

eccentric

feed.

Stitch

hand

or run

(220 rpm)

stitches

carry

and

each

out

the following.

(1).

shaft (2) within a

shaft

more than 90

reversed.)

when

the

feed

shaft

(2) in

the

length

dial

2

3

4

the

sewing

sew

using normal

way).

range

of 90

degrees,

index mark (3) on

set

screw

(1).

for

normal

feed

direction of A.

* If

the

than

for

Turn

4. After adjusting, gently pushing

regulator

(4).

stitch

lengthIsshorter

reverse

the

eccentric

securely the

eccentric

feed

tighten

for

shaft

(2) in the direction of B.

the

set

screw

shaft

(2) toward

normal

(1) while the

feed

3049M

23

T-8400A,

8700A

4.

ADJUSTMENT

4-11.

Rotary

hook

bases

position

When changing the gauge part width, or when adjusting the clearance between the needle and the rotary hook tip, adjust the

leftand right movement of the rotary hook bases.

< If

Models

with

thread

(7) (4) (7)-

01

Eccentric

faces

upward

trimmer

side

3050M

3051M

moving

large

amount

* When loosening or tightening the

a screwdriver into

underneath

1. Tilt

2. Loosen

3. Loosen

base

4.

Loosen

5. Loosen

*

Each

a the that

stop.

6. If

the

two bolts (8).

7. Move

approximate position (when

approximately 0.2 mm away from

position),

eccentric

(5) willbefacing upwardasshown in

8. Turn adjustments to hook and

theydonot

At

this

needle

(A)

When

*

tumed

hook

them.

9. Tighten

the

positionofthe

(about

1 mmormoreatone

the

cut-away

the

table.)

back

the

machine

the

four

the

two

(7)

can

move.

the

two

the

set

groupofthree

rounded

tip

lower shaft.

theydonot

sewing

the

rotary hook

and

then

sidesofthe

the

needle

bases

(7)sothat

the

rotary hook tip (9) is 0.05 mm or

touch.

time,

the

guard

between

the

until

bases

the

screws

head.

screws screws

screws

machine

(1).

(2) slightlysothat

(3).

(4) (three

set

that

fits into

Loosen

come

hasathread

screws

the out

base

tighten the

two needle

upper

positioning shafts (5) to

the

left

and

the

clearance between

clearance

between

(10) should be

needle

and

the rotary hook tip (9).

needle

they

upper positioning shafts (5)

feel stiff, you

(7) easily by running your

(2)

and

(3).

rotary

hook

side)

screws

(1) to (5), insert

partinthe

the

each

at left

and

(4)

has

one

the

V-shaped

set

screws

from

the

V-shaped

screw

only slightly

trimmer, loosen

(7) to

the

left or right to its

the

rotary hook tip (9) is

the

needle in its final

screws

(1). At this time,

upper

positioning

the

illustration at left.

right positions of

less

the

needle

smaller

can

than

then

the

move

bases

by a

>

oil

pan

rotary hook

right).

screw

with

stop

screw

shafts

make

fine

the

rotary

the

needle

butsothat

and

clearance

the

rotary

hand

along

(6)

so

the

are

in

(1) (8) (1)

3052M

(A)

0.05

mmorless

7

Distance (A)or

When

the

needle

needleIsbent

guard

needle and rotary hook tip (9) should not touch

and

toward

(10)dotouch.

the

rotary hook tip (9),

even

ifthe

less

the

needle

T-8400A,

8700A

24

4.

ADJUSTMENT

(7) L

Touching Touching

gently gently

10.

Lastly,

tighten the set screws (4) (three each at

right).

At this time, push the right spiral

gear

(11) gently to the

right (so that it gently touches the thrust washer (12)

inside the rotary hook base (7)). Also push the leftspiral

gear

(13) gently to the right (so that it gently touches the

thrust washer (15) in between the spiral gear (13) and

the

cover (14))

when

tightening

the

set

screws.

left

and

m

r>

3053M

3100M

Note:

After

tightening

and

force

order to make fine adjustments to the sideways positions

of the rotary hook

result.

11. For

thread

1) Tighten

2) Lower

3)

Loosen

4) Tum

that

the groove in

thread

the

spiral

gears

(11)

and

(13),donot

the

needle upper positioning shafts (5) to tum in

bases

(7), othenwise

trimming sewing

the

bolts (8).

the

needle

the

nut (16).

the

adjusting connecting rod (21) to adjust

the

roller (19) of

the

trimmer

machines

bar

to its lowest position.

the

thread trimmer

solenoid

main lever (18)

(17)ispressed.

cam

damage

(20) when

goes

5) Tightenthe nut (16).

t^

may

so

into

the

1

R

Q\9

(18)^(20)

< if

moving

For

example:

• When readjusting

• When changing small-width The amount of eccentricity in the needle upper positioning shafts (5) (refer to the illustrationon the previous page) is 1.7 mm.

Therefore, when adjusting to loosen

by a large amount" on (Steps 2.

the

positionofthe

the

clearance

the

screws (1). Carry out

the

and7.are

not required.)

rotary

hook

between

gauge

parts (suchas6.4 mm

the

sideways movement of

steps

1., 3., 4., 5., 6., 8., 9., 10.

the

bases

needle

3101M

by a

and

the

small

amount

the

rotary hook tip

<—•

4.8 mm or 4.8 mm

rotary hook

(about

bases

and

11. in "Ifmoving the position of the rotary hook

1 mmatone

•<—•

(7) to about 1 mm to

side)

3.2 mm)

>

one

side, you do not need

bases

25

T-8400A,

8700A

4-1

2.

Clearance

between

E

rotary

hook

and

needle

The

clearance

needle

plate

(2) Is

from the factory.

plate

(A)

between

adjustedasfollows at

the rotary hook (1)

4.

ADJUSTMENT

the

time of shipment

and

the

3054M

3055M

Without

T-8420A T-8421A T-8720A

With

T-8422A T-8722A

Check

clearance

hook (1)

are

To In

and

replaced.

adjust

between

(3).

Three

types thickness of and

replace

width.

Model

thread

trimming

thread

trimming

(A)

each

time

the

needle

plate (2) that affect

clearance

the

of thrust ring (4)

the

(A), replace

rotary hook (1)

and

are

thrust ring (4) that is currently being used,

it with a thrust ring (4) of

Part

code

SA4444-001 SA4038-001

S09260-001

Distance

0.9-1.2

1.4-1.7

parts

suchasthe

the

thrust ring (4) that is

the

rotary hook

available.

the

Thickness

0.8

1.0

1.2

(A)

mm

clearance

Measure

appropriate

mm mm

mm

rotary

(A)

base

the

Touching gently

/

3056M

When replacing screws

time.

Note:

(5). Be careful not to lose the thrust ring (4) at this

There is a piece of felt (7) for lubrication at

the

rotary hook (1), loosen

the

rotary hook shaft (6). Gently press down on

hook (1) when tightening the

rotary

hook

(1)

does

not liftup.

If

the

clearanceistoo

•

The

inner rotary hook may come out from

plate

(2).

If

the

•

clearance

Poor

thread

Is

too

tightening

large

small

set

screws (5) so that the

may

occur.

• Lower thread trimming errors may occur (models with

thread

trimmer).

• The right upper thread may be cut too short (models

with

thread

trimmer).

•

These

problems may occur particularly if

length is large or when carrying out thread trimming

during chaining-off.

three

base

the

set

of the

rotary

needle

stitch

T-8400A,

8700A

26

4.

ADJUSTMENT

4-1

3.

Clearance

between

rotary

hook

and

opener

4-1

4.

Presser

foot

height

3057M

1. Loosen the

set

screw (3) and

move

the

opener

(1) to

left or right to adjust so that the clearance between the

rotary hook (2) and the opener (1) Is 0.1-0.3 mm when

the

opener

of

the

2. Tighten the

Note:

If

the

clearanceistoo

• Upper thread trimming errors may occur (models with

thread

• The right upper thread may be cut too short (models with

thread

If

the

clearance

•

The

•

The

1.

Remove

2.

Loosen

(4).

3.

Use

4. Loosen

down to adjust

approximately 7 mm

(1) is pulledasfarasit

arrow.

set

screw

(3).

large

trimmer).

Is

too

rotary hook may become

opener

the

lifting

the

(1)

rear

nut (3)

screw

small

may

become

cover

(1) and

and

loosen

lever (5) to raise

(7) and move

so

that

above

damaged.

remove

the

topofthe

will

go in the direction

the

rubber

presser

adjusting

foot (6).

presser

needle

cap

screw

bar

(8) up or

foot (6) is

plate.

the

(2).

G

n

Note:

Do not

5. Tighten

6. Tum

foot

the

pressure,

tum

the

screw

presser

the

adjusting

and

presser

(7).

then

bar

(8)atthis time.

screw

tighten

(4) to adjust

the

nut (3).

the

presser

Approx.

7mm

3059M

27

T-8400A,

8700A

4-1

5.

Installing

the

feed

dog

4.

ADJUSTMENT

4-1

Touch

6.

Feed

dog

—14144^

position

3060M

3061M

1. Install

2. Tighten

3. Tighten

*

<

Forward-back

Carry out this adjustment if

the

clearance

(13.3-13.7

1.

2. Tum

3. Tighten

the

feed

screws

of (1).

The an

Loosen

needle

dog (2). (The

goes

whenitcomes

the

angle.

feed

set

dog

the

needle

into

(3).

the

screw

the

nut (5) to

screw

are

between

mm) is correct.

the

two

feed rocker

drops into

the

screw

dog

(1) to

feed

dog

support

(4)

touches

secure

(4) is

not

position

not positioned correctly

the

screws

the

middle of

will

actuallybeslightly to

feed

dog

out.)

(1).

the

feed

bar

(2) with

set

screw

(4)sothat the tip

the

bottom of

the

set

screw

(4).

used

for installing

adjustment

the

needle

(1).

base

(2),

bar

arm (3) to adjustsothat the

the

needle

and

will

the

>

and

the

even

and

the

hole in

the

be slightly to the back

the

two

the

feed dog

feed

dog

at

needle hole in

though the

presser

front

the

when

bar

feed

it

Needle

Should

touching

any

points

3062M

not

at

Note:

Do not overtighten

damage

<

Left-right

Adjust

so

needle plate (4) when

bed

with

Ifthe

needle

screw (1)

be

to

adjust.

the feed rocker

position

that

neither

the

screws

plate and

and

move

the

base

adjustment

sideofthe

the

needle plate (4) is

(5)

and

(6).

the

feed dog

the

feed

screw

rocker

(1), othenwise it

arm (3).

>

feed dog

secured

are

touching, loosen the

base

arm (3) sideways

touches

will

the

to the

3063M

T-8400A,

8700A

28

4.

ADJUSTMENT

4-1

7.

(2)^

y/Mmi

Feed

dog

r ' 1 1

(1)—^

height

\y/y

0.9

-1.1mm

1

j

3064M

3065M

Tum

the

highest position,

(1)protrudes 0.9-1.1 mm from

1.

2. Loosen the

3. Turn

4. Securely tighten

5.

Note:

If

•

• It

• Lower thread trimming

if

•

• It

•

machine pulley forward until

and

Tilt

back

the

machine

screw

can

slide.

the

height

adjustment

illustration to

adjust

the

Recheck

the

The The length dial setting. Thread

normal

thread

the

The length dial setting.

normal

The

thread

the height of the feed

feed

dogistoo

feed

dog

may

stitch length

tightening

may

be difficult to obtain uniform stitch lengths for

feed

and

reverse

trimmer).

feed

dogistoo

stitch length

may

be difficult to obtain uniform stitch lengths for

feed

and

feed dog

trimmer).

reverse

may

then adjust

the

head.

(3) just

enoughsothat

the

height of

screw (3).

high

touch

the

may

become

maybepoor

feed.

errors

low

may

become

feed.

touch

the

top of

screw

the

dog

needle

when

may

movable knife (models with

• Large variations in stitch length may

fast

sewing

speeds.

the

feed

dog

so

that

the

(5)asshowninthe feed

the

needle

the

feed

dog

(1).

(1) isatits

feed dog

plate (2).

(1).

plate.

longer

shorter

using

occur

than

the

thick

threads.

(models with

than

the

occuratslow

bar

stitch

(4)

and

29

Lower

@

3066M

T-8400A,

8700A

4-1

8.

Feed

dog

angle

Front

-

raised

Standard

4.

ADJUSTMENT

The standard angle for the feed dog is when the mark (2) on

the

feed

bar

the

feed

rocker

base

arm

(3).

1.

Tilt

back

the

2.

Loosen

the

machine

set

screw

head.

(5).

3. Insert a screwdriver into the slit (6) in (1),

and

shaft (1) is aligned with

4. Tighten

turn itto

the

set

make

screw

the

(5).

the

adjustment.

reference line (4) on

the

feed

bar

shaft

Front

lowered

* When

the

angle of

fonward-back position of

the

two

the

feed dog in

accordance

In

screws

(7)

accordance

with

* In addition, when

the

height of

the

feed dog.

and

the

feed

the

feed dog is adjusted, the

the

adjust

feed dog

the

with the

will

forward-back position of

needle

needle plate).

angle of

dog

will

the

feed dog is adjusted,

also

change,soreadjust

change.

Loosen

(for lower feed,

the

3067M

T-8400A,

8700A

30

4.

ADJUSTMENT

4-1

9.

Rear

of

sewing

Tension

machine

release

3005M

Carry out adjustmentsasfollows

tension

lever.

If

mm

1.

2. Tighten the

the

tension

Loosen

opening

discs when,

disc

the

nut (1).

set

amount

presser

foot is raised using the

opening

screw (2) to adjust the tension disc

to 0.8 mm.

3. Tighten the nut (1).

If

the

tension

Check

underside

disc

opening

that the tip of the

of the tension

release

amountisnormal

set

based

on the status of the

amountissmaller

screw

(2) is touching the

plate (4).

than

lifting

0.8

(1)

(4)

0.8

mm

3006M

31

T-8400A,

8700A

4-2

0.

Thread trimming timing (Modeis with

thread

4.

ADJUSTMENT

trimmer: T-8422A, 8722A)

3068M

(2)

3069M

3070M

<

Checking

1.

Remove

2.

Tilt

back

method

the

needles.

machine

>

head.

3. While pressing the thread trimmer solenoid (1), tum the machine pulley

fonA/ard

stiff to turn (the point

until

where

the

machine pulley

the

movable knife starts

becomes

moving).

4. The "T" mark on

the mark (2) on

At this time,

2 mm from

* Check

the

of

the

"T"

the

allowable

the

centerofthe

machine pulley

motor cover.

range

mark (2).

must

for

the

'T" mark is within

be aligned with

thread trimmer timing according to

mark

when

the

movable

knife

makes

the

position

its

first

slight movement.

Note:

rT

Early

33-45mm

3071M

If

the

thread

trimming

timingistoo

early

• If it is extremely early (4 mm or more), thread trimming

errors

will

upper

occur.

upper

thread

thread may be

cut

extremely short.

trailing length willbetoo long after

• The right

•

The thread trimming.

Ifthe

upper

thread

picked up by

performance

trailing length is

the

pre-tension

will

become

poorer.

and

too

long, it will not be

the

lower thread holding

(The correct upper thread trailing length after thread

33-45

trimming is

If

the

thread

trimming

mm.)

timingistoo

late

• If it is extremely late (4 mm or more), thread trimming

errors

will

occur.

• The upper thread trailing length

will

be too short after

thread trimming (about 30 mm).

[Checking

1.

Open

2. Under actual sewing conditions,

pulley to

3. If

when

of If come cut

method]

the

slide plate.

cut

the

thread

the

rotary hookasshowninthe

the

thread

outofthe

and

the

threads.

trimming is normal,

upper thread is held by

trimming timing is late,

loop

upper

spreader

thread

tum

the

thread

the

loop

illustration.

(3)

when

will be too short.

the

machine

willbetrimmed

spreader

the

thread

the

thread is

(3)

will

Upper

thread

T-8400A,

8700A

32

4.

ADJUSTMENT

<

Before

Check that

adjusting

the

index mark (2) on

* If

the

Index

marks

screws (3)

and

>

index mark (1) on

the

pulley holder

(1)

and

(2)

the

are

align the index marks (1)

machine pulley

are

aligned.

not aligned,

and

(2).

and

loosen

the

SflM

3072M

<

Adjustment

1.

Loosen

(Check

the

that

method

four

set

screws

the

thread trimmer

shaft (6).)

2. While

pressing

thread trimmer

startstobecome

3.

Secure and

then

"T" mark on

the

cam

thread

align

the

machine pulley.

thread trimmer solenoid (7),

(5) in

stifftoturn.

trimmer

mark (8) on

4. At this position, tighten At this time, cannot

5. Check trimmer the ball bearing

*

The

(11)onthe

feed

shouldbealmost

Repeat

6.

page.

make

move

that

cam

sure

sideways

the

mark (9) in

(5) is roughly aligned with

bush

same

applies

ball bearing

and

one

for

the

steps

in "Checking method" on

>

(4).

cam

the

direction of

cam

(5)sothatitcannot

the

four

set

that

the

(so

that

there

the

(10) at this time.

for lower feed.

bush

lower

feed-and

opposite

the

first.

(5) is free of

motor

screws

thread

trimmer

is no

middle of

the

There

(10) -

the

arrow until it

cover (4).

gap

at (A)).

the

mark (11) on

are

two

one

for

second

the

tum

move,

with

cam

thread

marks

needle

the

(5)

mark

3073M

33

T-8400A,

8700A

4-2

1.

Replacing

trimmer:

the

fixed

knife

T-8422A, 8722A)

3074M

and

movable

<

Removal

1.

Remove

2. Loosen the screw (1), remove remove the needle plate (3).

3.

Remove

knife (5).

* Be careful not to

knife (5)

4.

Remove

fixed knife (7).

>

the

knife

needles

screws

when

shoulder

(Models

and

raise

(4)

and

damage

removing it.

screws

the

then

the

(6)

presser

pan

4.

ADJUSTMENT

with

foot.

screw

(2),

remove

edgeofthe

and

the

then

thread

and

movable

remove

then

the

r/

3075M

3076M

Sharpening

the

If

sharpen * The movable knife (5)

normal

the

fixed knife

thread is not being cut easily,

the

fixed knife (7)asshown in

whetstone,

andsoit

useawhetstone

the

illustration.

cannot

be

sharpened

shouldbereplacedifneeded.

using a

(8) to

T-8400A,

8700A

34

4.

ADJUSTMENT

^Nr\

(5)^

0.05-0.2mm

k ^(2)

3077M

<

Installation

1. Tum

2. Provisionally install

3. While

the

being pulledasfaraspossible in

and

then

(3).

* Install

finger, slide

the

tip of

0.05-0.2

* If

the

or if

result.

4. Install

shoulder

5. Install

>

machine pulley by hand until

secure

the

machine

the

movable knife (2) with

the

movable

pressing

the

mm,

movable

the

gapistoo

the

fixed knife (6) to the needle plate (7) with

screws

the

needle

knife (2)

the

topofthe

movable knife (2) until

movable

and

then

securely tighten

knife (2)

large, thread trimming errors will

(8).

plate (7) with

screw (10).

6. Install

presser

the

needlestothe

foot.

the

pulleysoit will

above

movable

knife (2) and

and

the

stopper

the

screw (9)

needle

clamps

the

direction of

the

opener

not

plate spring (4).

knife (2) with

the

gap

the

stopper

the

screws

(5)

are

and

the

tum.

the

screws

between

touching

the

lower

(1) is

arrow,

your

(5) is

(3).

the

pan

the

4-2

2.

Movable knife

position

Should gaps

3078M

(Models

be

no

with

<

Vertical

1.

Remove

thread

2. Loosen screw

(4) of

3. Move that

the

knife bracket (6).

4. Adjust

Note:

If

the

•

If

the

•

• Lower

the

so

that

hook

bases,

screw

(4).

movable

The

operationofthe become The

threads

movable

Thread The

movable

the

sewing

thread

trimmer: T-8422A, 8722A)

position

the

movable knife lever (7) up or down to adjust

movable knife (5) gently

set

there

stiff

trimming

machine

needle

set

the

adjustment

plate.

screw

thread

trimmer lever (3).

(2) of

the

>

set

touches

collar (1)

the

collar (1) and the thread trimmer lever (3)

arenogaps

and

then

knifeisbelow

and

the

will

notbecut cleanly.

knifeisabove

errors

knife willtouch

holding will

tighten

thread

sewing

willoccur.

willstop.

become

between

the

movable

trimming

machine

the

movable

the

sewing

poor.

them

set

may

and

screw

knife

mechanism

stop.

knife

machine

(2)

bracket

and

movable

the

rotary

and

bracket

bed

the

so

the

will

and

(3)-

3079M

35

T-8400A,

8700A

27.2±0.3mm

27.2+0.3mm

3080M

<

Forward-back

The

standard

are

showninthe

position

installation

illustration.

adjustment

distances

If adjustment is necessary, loosen

the

thread

back

and

trimmer

forth.

lever

and

move

for

the

4.

ADJUSTMENT

>

the

movable

screws

the

movable

(8)

knife (5)

and

(9) of

knife (5)

3081M

Note:

When adjusting the position of

0.5-1

mm.

If

the

movable

knife istothe

• Ifthe movable knife is a long way to the front, upper thread trimming errors

• Lower

thread

holding willbepoorer

Skipped stitches or thread pulling out

large-capacity

• The

upper

At

the

right

threadtobe

If

the

movable

rotary

hooks.)

thread trailing length

side

in particular,

cut

extremely short.

knife Istothe

• Upper thread trimmingerrors

errors

will

• Lower

occur.

thread

holding willbepoorer

Skipped stitches or thread pulling out

large-capacity rotary

• The

upper

If

the

performance

thread trailing length

upper

thread trailing length is too long, it

will

hooks.)

become

(The correct upper thread trailing length after thread trimming is

the

front

the

back

will

poorer.

movable knife,

(if

the

after

will

be too

cut

endofthe

(if

the

distances

thread

trimming.

occuratthe short

after

upper

distances

installation

are

smaller

distances

than

the

showninthe

standard

will

sewing start. (Take particular

thread

trimming.

thread

will

remain

near

are

larger

than

the

standard

illustration

distances)

occur.

care

of this on sewing

the movable knife

distances)

occur. In addition, ifthe movable knife is a long way to the back, lower thread trimming

after

thread

will

be too long after thread trimming.

trimming.

occuratthe

will

sewing start. (Take particular

notbepicked up by

33-45

the

mm.)

care

of this on sewing

pre-tension and

• When the article being sewn is removed after thread trimming, the end of the upper thread

spring

because

the upperthread trailing length is too long,

and

this

will

cause

resistance.

above

should be within ±

machines

anditwill

cause

machines

the

lower thread holding

will

be pressed by the plate

the

with

upper

with

T-8400A,

8700A

36

4.

ADJUSTMENT

4-2

3.

With twin

so

the

plate

Plate

needle

sewing machines,

spring

adjustment

(Models

the

mustbecarried

thread

cannotbesewn

out

correctly.

7mm

3082M

trimmer:

unless

the

When

the

The

the

gap spring (1) to

movable

plate

spring (1) Is 7 mm.

Installation position for

Illustrationatleft.

between

the

0.5-2.0

T-8422A,

lower

threads

knife Is not Installed,

Loosen

8722A)

are

held after thread trimming,

the

plate spring (1) Is shown In

the

screw

movable knife bracket (3)

mm.

the

correct

(2)

and

height for

adjust

the plate

the

Aligned

0.5-2.0mm

3083M

3084M

When

the

movable

•

The

endofthe

undersideofthe

knifeIsinstalled...

plate spring (1)

movable

knife (4). If Itonly

touches

flush against

touchesatan

angle, skipped stitches or thread pulllng-out problems

may

occur.

In particular,

threads

The

standard plate spring (1) movable knife (4) Is roughly aligned with

of

the

plate

are

these

finer

than

positions of

are

spring

problems

the

(1).

lower

the

positions

may

occurIfthe

threads.

movable knife (4) and

where

the

hook tip of

the

rounded part

(Refer to "Forward-back position adjustment" for

movable

knifeonthe

the

upper

the the

the

3085M

Note:

if

the

lower

•

Skipped

if

the

•

Skipped

37

lower

thread

stitches

thread

stitches

holdingistoo

or thread pulling-out problems

holdingistoo

willoccur at

strong

weak,orif itisunevenatboth

the

sewing

start.

will

occur

T-8400A,

at the

sewing

8700A

start.

sides

4-2

4.

Tension

release

Approx.

wire (Models with

3086M

0.8mm

if

the

trimming, or if following

* Lower

the

If

(the

during

1. While

2. The tension

3. If

4.

thread

upper

trimmer:

thread

trailing length is too short after thread

the

tension

adjustments.

the

upper

tension

thread

pressing

presser

thread

foot before making the adjustments.

trailing

release

wire

trimming)

the

thread

machine pulley forward.

discs

(4)

when

the

roller of

the top of

the

mm,

* If

Check

the

tension

tum

there

the

left

the

set

(6) with

that

tension

the

is a difference

and

screw

projection on

close

when

adhesive.

the

projection on

discs

(4) do not

nut

(5) to adjust.

right

tension

(6). After adjusting,

tension

release

the

thread

rollerislevel.

4.

ADJUSTMENT

T-8422A, 8722A)

discs

stay

open,

carry out

lengthistoo

does

trimmer solenoid (1), tum the

open

by approximately

tension

the

release

thread open

between

discs

(4)

lever

(2)

trimmer

short

not

operate

lever

trimmer

by approximately 0.8

the

opening

(4), you

open

reaches

cam

secure

when

(3),

can

the

and

the

sufficiently

0.8

mm

(2)

reaches

cam

(3).

amounts

adjust

using

set

screw

the

roller of

topofthe

that

they

of

Roller

Projection

3087M

If

the

tension

1.

Check

position.

2. Check that

removed.

3. After carrying

that

discs

the

out

remain

tension

the

open

release

above

lever (2) is in its original

lever spring (7) is not

checks,

adjust using

(5).

* If adjustment is not possible, replace the tension

wire (8).

Note:

If

the

tension

•

The

is

passing

•

The

thread

If

the

tension

•

Thread

•

Damagetoparts

disc

running of

through

upper

thread

trailing

disc

tightening

openingistoo

the

thread

the

tension

will pull

length

from

openingistoo

problems

will result.

small

will be sluggish

discs.

outofthe

the

needle

needleorthe

maybetoo

large

willoccur.

when

the

short.

the

nut

release

thread

upper

Underside

of

tension

3088M

T-8400A,

8700A

38

4.

ADJUSTMENT

4-2

5.

Thread

(Models

rXlGt^

wiper

with

thread

trimmer:T-8422A, 8722A)

1.

Stop

the

3089M

2.

Tum

off

3.

Set

the

<

Forward-back

4.

Remove

5.

Loosen down to

0.3-0.5 solenoid

illustration.

6.

Securely

7. Install

Note:

if

•

if

•

the

distanceistoo

The

thread

the

distance

Thread

sewing

the

stitch length dial to "2".

the

mm in front of

wiping

machineinthe

power

position

solenoid

screws

adjustsothat

link (2) is

tighten

the

solenoid

wiper

(3)

is

too

errors

switch.

cover

(4)

pushed

screws

cover

large

may

smaii

willoccur.

adjustment

(1).

and

move

the

tip of

the

tip of

by

(4).

(1).

touch

needleupstop

>

the

solenoid (5) up or

the

thread

the

needle

hand

as

showninthe

the

presser

foot.

position.

wiper (3) is

when

the

(2)^

(3)

0.3-0.5mm

3090M

<

Left-right

8.

Pass

9. Loosen

the

position

thread

the

screws

through

left or right to adjustsothat

wiper (3)

10.

Securely

securely

tighten

hold

the

adjustment

the

needle.

(6) and

the

screws

move

the

threads.

(6).

>

the

thread wiper to

hooked parts of the thread

the

Approx.

39

0.3mm

3091M

T-8400A,

8700A

Approx.

3092M

3mm

<

Return

11. Loosen

12. Securely tighten

•

position

downtoadjustsothat

thread

3 mm

the

wiper (3)

when

forward-back

screws

and

the

thread wiper (3)

the

The

tip of

the

thread wiper (3) may not hold

of thread,

needlesothat

so

bring

the material cleanly. In addition, screw

does

not

touch

Note:

If

the

distanceistoo

•

The

thread

if

the

distance

•

The

thread

wiper (3) may touch

wiper (3) may

large

is

too

small

adjustment

(8)

and

move

the

distance

the

presser

screws

the

thread wiper (3) close to

thread

can

the

needle

touch

the

between

bar

has

returned.

(8).

still be pulled out from

check

wiper (3).

the

needle

the

presser

4.

ADJUSTMENT

>

stopper

(7) is approximately

that

the

some

the

clamp

bar

(9) up or

tip of

types

needle

(10).

(7).

the

the set

3093M

3094M

< Vertical

13.

The

illustration.

14.

Loosen

(12) to needle

position

path for

the

adjustsothat

and

solenoid link (2) is

illustration.

15.

Securely

Note:

The

slightly

Carry

that

occursatthese

If

the

•

Thread

If

the

•

The

tighten

stopping position for

after

out

the

clearanceis0.5-1

distanceIstoo

wiping

distance

thread

adjustment

the

tip of

the

thread wiper(3) is shown in

screw

(11)

and

the

thread

wiper (3) is

pushed

the

screw

(11).

thread

trimming

times.

large

errors

is

too

small

wiper (3) willtouch

the

trimming.

will

occur.

mmatthe

>

tum

the

thread

gap

between

by

handasshowninthe

tip of

several

the

needle.

0.5-1

the

times,

lowest

the mm when

needle

and

wiper

tip of

will

adjust

position

the

guard

the the

vary

so

that

0.5-1

mm

3095M

T-8400A,

After adjusting, carry out a

thread

wiping is carried

8700A

out

correctly.

test

sewing

and

check that

40

4.

ADJUSTMENT

4-2

6.

W88

Adjusting

88888888

the

needle

(1) (3) (4)

m

up

(-10-20)

(SI©e

Becomes

stop

2210M

higher

lower

position

The

needleupstop

the

sizeofthe

great.

1. While power

2. "n.O

XX" ("xx" is and

"0" is

3. Press the

setting

•Ifyou

up to 20

lower.

•Ifyou

down to -10

become

4.

Press

A long

change the

needle up

* A setting value of "10"

of approximately 10° for

sewing load. Adjust if

pressing switch.

will

appearinthe

the

setting value for

the

default setting.)

rightmost

value

for

press the A

and

pressthe V

higher.

the

ENTER key (4) for two

buzzer

to stitch number display

stop

position will

the

needle

main display (2).

A or V

the

needleupstop

key,

the

needleupstop

key,

and

the

will

sound

position setting.)

correspondstoan

the

vary

up/down

the

needleupstop

key

the

setting

the

setting

needle

seconds

and

the

mode.

upper

shaft.

slightly

the

difference is

key

(1), turn on

(3) to

position.

value

position will

value

up

stop

or more.

main

display (2) will

(This

angle

depending

position,

change

will

increase

become

will

decrease

position will

completes

of rotation

on

too

the

4-2

7.

Adjusting

the

treadle

2913M

2301M

<

Forward

If

the

simply resting on

tobetoo weak, treadle

* a is

lighter at b

<

Backward

1. Loosen * When the bolt (4) is tightened,

2. Tighten

<

Adjusting

Remove the nut (5),

(6) from

The

treadle stroke will

27%.

At this time,

sensitivity will

depression

machine

spring (1) is hooked

the

starts

the

adjust

heaviest,

and

c.

running at low

treadle, or if

and

depression

the

nut (3)

and

becomes

operation

the

heavier,

becomes

the

nut

(3).

the

treadle

and

position in figure A to

the

treadle

change,soreadjust if

sensitivity

the

onto

the

sensitivity

turn

and

lighter.

stroke

then move

thenbeincreased

forward

2138M

adjustment

speed

when

the

treadle

position (a to c)atwhich

the

treadle

setting

becomes

pressure

lever (2).

2139M

>

your foot is

progressively

adjustment

the

bolt (4).

the

treadle operation

when

it is

loosened,

>

the

connecting rod joint

the

position in figure B.

by approximately

and

backward

necessary.

depression

is felt

the

>

the

2302M

41

T-8400A,

8700A

4-2

8.

Adjusting

the

rotary

hook

A

lubrication

CAUTION

Be careful not to touch your fingers or the lubrication amount check

*

A

hookorthe

result.

feed

mechanism

when

checking

the

amountofoil

amount

sheet

against

suppliedtothe

4.

ADJUSTMENT

moving parts suchasthe rotary

rotary

hook,

othenA/ise

injury

may

Use the following procedure to check

when

changing

More

(A)

oil

Too

much

the

sewing

speed.

Less

01

Spattered

(B) (C)

Correct

the

amount of oil being supplied to the rotary hook when replacing the rotary hook or

<

/)

[9-14inm

2942M

Guidetolubrication

1.

Tilt

back

the

machine

2. Tum

<

1. Tum off

2.

3.

4. Use

5.

6.

the

oiladjusting

within

9-14

mm.

Checking

Remove

to

the

Remove

Tumonthe Run approximately 1

(following

the

power

the

thread

needle.

the

needle

the

liftinglever to lift

power

the

machine

the

lubrication

same

adjustment

head.

screw

(1) to adjust the height to

amount

switch.

from all points from

and

the

bobbin.

the

presser

switch.

at

the

normal

minute

without

start/stop

pattemaswhen actually

>

the

foot.

sewing

thread

sewing).

7.

Place

the

oil

Too

little

3099M

lubrication

the rotary hook (the right side is

and

hook), machine at seconds.

lubrication

8.

Check

sheet.

* If

the

lubrication will

hold it In place while running

the

(Any type of

amount

the

amount

sewing

machine at 3,000 rpm or less,

sideofthe

<

Adjusting

1.

Tilt

back

2. Tum

amount.

• If

counterclockwise, greater.

• If

clockwise,

3.

Check

procedure given in "Checking

above.

•

Tum amount

correct.

4.

Check machine

the

illustration

the

machine

adjusting

rotary

lubrication

the

adjusting repeatedly

lubrication

has

been

the

amount

normal sewing

paper

check

sheet

of oil which

machine

tend

speed

to be

greater.

willbecorrect.

lubrication

head.

screw

hook

lubrication

used

(1) to

adjusting

the

lubrication

adjusting

amount

screw

until

amount for

approximately

check

the

speed

can

(2).)

has

is fast,

the

amount

again

the

(1)

and

the

again

sheet

(2) to

right side of

for approximately 8

be

spattered

the

If running

amount

(0)inthe

>

adjust

lubrication

the

screw

amount

screw

becomes

according to the

lubrication amount"

check

after

two hours.

take-up

speed

any

the

used

amount

the

material

the

rotary

sewing

as

onto

sewing

for

left of

the

right

lubrication

(1) is

(1) is turned

the

tumed

becomes

smaller.

lubrication

amount

the

sewing

of

is

T-8400A,

8700A

42

4.

ADJUSTMENT

4-2

9.

Adjusting

the

^(2)

presserfoot

IlilliiH

i

Floating

^(3)

30g6M

amount

floating

amount

• When sewing stretch materials and materials with long

pile, you can make minute adjustments to the floating

amount for

material.

• In addition, this

working

1. Tum the sewing machine pulley by hand to move the feed

dog (2) below

2. Use the

3. Loosen

4. Use a hexagon wrench to tum the adjusting screw (5) to

adjust

5. Tighten the nut (4).

• After making

check

when

lifting

the

• To raise Tum

• To lower

Tum the adjusting

the

(minute lifting

the

presser

can

be useful for increasing

sewing

the

lever to lower

nut (4).

floating

the

floating

curves.

needle plate (3).

amount.

presser

adjusting

presser

foot

screw

foot

screw

adjustment,

amount.

foot (1) in

the

(1)...

accordance

presser

(5) clockwise.

(5) counterclockwise.

sewapiece

amount)

foot (1).

with

the

ease

of material to

of

Lower

3097M

<

Guidetoadjustment

When

the

material is placed

the feed dog (2) is moved to its lowest position and

material is moved,

the

material.

If

the

floating

•

Ease

of working (handling) will be

curves.

If

the

floating

• The stitch lengths

there

amountistoo

when

under

should ideally be

small

large

and

seam

lines

sewing

curves

the

presser

some

poorer

willbeunstable.

>

foot (1)

resistance in

when sewing

and

the

43

T-8400A,

8700A

5.

APPLYING

Be

suretowear

into your

0

Furthermore, do not drink

diarrhea.

Keep

eyesoronto

the

oil

GREASE

A

CAUTION

protective goggles and gloves when handling

your

skin, otherwise inflammation

the

oil or

eat

the

grease

outofthe

reach

of children.

can

under

the

lubricating oil and

result.

any

circumstances,asthey

5.

APPLYING

GREASE

grease,sothat they do not get

can

cause

vomiting and

5-1.

If

the

apply

<Rear>

When

GREASE

greasetothe

indicator (1) illuminates

nwonftaa.

When the lannp When me lamp flunniios mecpenaononly.enaoddeni atsfiGaffin

itddfl.

CianmBbnxaiatt

eneetUiiasasara

dbaonxntraounacddcnle.

the

GREASE

sewing

O ©

POWER

machine.

«ioxxa6Lait«^8diinsEB^cMZT.

dtdng

must be replenished. H cperation is cominued wilhaut

HfltraaaBaRM.n-SBU'XasnafliB. taattanaaamBdfSAaifisintMinaB. Cusndo

lubticenle

Oumnatn

nigM be

ts Umparaseenciendeysuena

especiSeado.

|Consu!le d Manual de inseucdoncs.)

indicator

and

Apply

0-«t

GREASE

end the alarm

catoed

(See

Sise

oondnua

the

buzzer

grease

(naufioiBexH)

sounes.mespecifnd

nstrucbon menual.)

la alarma. se

usandesin

luhneaf.sepe^

illuminates (T-8420A, 8720A:

sounds

while referring to

greese

replenishmg.

(•«anua«)

debe

egrogar

grease

d

causar

each

time the

the

treadleisdepressed,itmeans

following

page.

Buzzer

Semi

that

dry

type)

it is time to

2994M

<To

continue

1.

Press

(The buzzer

*Useanobject with a

the

sewing

RESET

will

temporarily

without

switch (2) for approximately

stop sounding but the GREASE indicator (1)

sharp

point to

firmly

push in the RESET switch (2)asfarasit

applying

one

second.

grease>

will

remain illuminated even when the treadle is depressed.)

will

go.

2. Sewing can continue in this condition, but ifthe cumulative sewing machine operating time reaches a further 10 hours, the

buzzer

procedureonthe

* if

problems

will

you

continuetouse

with

start sounding again, if this happens, apply

following

the

sewing

page.

the

machine

sewing

machine

may

result.

after

carrying

T-8400A,

grease

out

8700A

and then reset the alarm display by referring to the

the

reset

procedure

but

without

applying

2995M

grease,

44

5.

APPLYING

GREASE

<Applying

GREASE

1.

Using

grease>

BZL-301

(SA2694-001)

Blue

30

mm

the

tube

2934M

NOTE:

• Use only the

tube>

specified by Brother.

• Do not

white

• Do not

tube

use

with this

the

tube for any models with "Use only the

specified by Brother".

Purchase

applying

the

grease.

grease

<BZL-301 (SA2694-001) in the

the

BZL-300 (SA2355-001)

sewing

machine.

BZL-301 (SA2694-001)

except

grease

unit

for

those

<BZL-301

(SA2693-001)

greaseinthe

grease

which

are

(SA2694-001 )>

to

blue

in the blue

indicated

use

for

2935M

2.

Applying

Follow

the

procedure below to apply

Insert

the

(1) all

the

in

the

part.

1.

Tum

the

2.

Remove

3. Apply

the

greasetoeach

4. Tighten the

grease

|r—j

tip of

way

into

power

switch to "OFF".

screw

the

nozzle

the

hole

(2). (Refer to

ofthe holes

(2) to push in

greasetothe

-(2)

the

until

the

grease.

places

indicated by arrows on

Apply

grease

letting itspill out.

page

for greasing locations.)

grease

overflows slightly.

5.

Use (2).

6. Apply

7. Carry

Note:

•

Once

tube,

•

The

grease

• When using the grease again, remove any old grease from inside

nozzle

(Store

the

grease

remaining

performance.)

the

1

R

N

S >

s

h

-d)

without

a cloth to wipe

grease

out

the

grease

attach

the

away

to all locations reset

procedure

tube

has

cap

securely

any

excess

shownonthe

givenonthe

been

opened,

and

store

shouldbeusedasquicklyaspossible.

first.

tube

away

inside

carefully

the

tube

once

may

the

deteriorate,

page.

Tighten the

grease.

grease

the

tube

remove

tube

has

and

the

screwtopush

from

the

in a cool

been

opened,

this

may

(2)

in

2936M

around

the

screw

same

way.

nozzle

from

dark

place.

otherwise

affect its lubricating

the

2937M

45

T-8400A,

8700A

P[llll][|

5.

APPLYING

GREASE

2996M

*

Pour

oil

<Resetting

(i

i

Into

the

cumulative

I) (J)

POWER

FOWEM

«0(fZttLII^4EatBO»BE«V»r.

?w

spmer«

ervyatMoawb*cauMd

atMaczH

sAflasazzatf

TftAc.

masjssiMftiieaazmuittatiBo.

oil

coveratthe

grease

»(OonauiaaittaMioa

CREASE

«-aai»KiuttjnB.

same

operating

SRSASa

(ttOBSWfeil)

i

o

lit

iiBncar.Mpeoria

Ffn

time.

time>

brother

up

alarm

Q

(1)

Turn the machine pulley until

screw

Use

the apply block slider (2).

Once

the

grease

below to

reset

applications.

1.

Press

the

RESET

short

beep

(about

switch

once

the

* Use an object with a

RESET switch (1)

2.

Press

the

RESET

5

seconds.

A long

<Checklng

Ifonly

machine out

beep

procedure

method

the

POWER

is next

successfully.

(about 2

willbe carried out.

used,

(1)

canbeseen.

tip of a

screwdriverorsimilar to

5-10mmbeadsofgreasetothe

5-10mm

4

placesattop,

bottom, left

of

the

has

been

applied, follow

the

cumulative time

switch (1) for

0.5

buzzer

sounds.)

as

switch (1)

seconds)

after

resettlng>

seconds)

sharp

farasit

about5seconds

sounds.

point to firmly

will

once

more

will sound,

indicator (2) illuminates

the

reset

procedure

and

slide

block (3)

the

between

(Release

go.

for approximately

and

when

has

the

slide

right

2939M

procedure

grease

push

the

sewing

been

until a

the

in the

reset

carried

2997M

Note:

If

the

reset

procedure

Ifthe GREASE indicator (3)

has

not

been

carried out successfully,

does

not illuminateand the buzzer

repeat

steps1and

does

not sound when the RESET switch (1) is pressed,

2 above.

operate the sewing machine for more than 30 seconds, and then carry out the reset procedure again. The RESET switch (1) should never be pressed except when carrying out the reset procedure after

T-8400A,

8700A

grease

application.

46

5.

APPLYING

GREASE

5-2.

When

"GREASEUP"

appears

(T-8421A, 8422A, 8722A:

Semi

dry

specifications)

If"GREASEUP" flashes on the main display (1) and a buzzer sounds when the power switch is turned on, it means that

will

grease needs to be applied. (The sewing machine

Apply

grease

while referring to

(2)-

the

following

page.

not operate at this time, even ifthe treadle isdepressed.)

r . c o ^

jj

r t n j

LOCK

/T\

/TN

A A A

A]

iJ

<To

continue

1.

Press

2.

The

main display (1)

(The power indicator (3)

NOTE

• If you do

power indicator (3) procedure on

• If you continue to

without carrying out

be forcibly prevented from operating for Ifthis

* If

you

problems

sewing

the

RESET

happens,

not

key (2).

apply

the

apply

will

following

continuetouse

with

the

sewing

temporarily

change

will

grease

will

flash

use

the

reset

grease

the

machine

without

to stitch number display mode, and sewing

flash.)

when

the

each

page.

sewing machine after

procedure), "ErrlOO"

and

carry

sewing

machine

may

applying

"GREASEUP" notification

time

the

power is turned on until you

safety

reasons.

out

the

reset

grease>

the

"GREASEUP" notification

will

appear

procedure.

after carrying

result.

out

(7) (6) (8)

will

be possible when

appears,

after a certain period of time

the

reset

notification

reset

the

appears

procedure

will

notification by carrying

but

the

treadle is

continue to

without applying

and

the

appear

sewing machine will

without applying

(4)

2191M

depressed.

and

the

out

the

grease

(or

grease,

47

T-8400A,

8700A

5.

APPLYING

GREASE

<Applying

GREASE

1.

Using

grease>

BZL-301

(SA2694-001)

Blue

30

mm

the

tube

NOTE:

2934M

Purchase

applying

o ® ^

• Use only the

tube>

• Do not

white

• Do not

tube

for

grease

specified by Brother.

use

the BZL-300 (SA2355-001)

tube

with this sewing machine.

use

the BZL-301 (SA2694-001)

any

models

with "Use only the

specified by Brother".

the

grease

grease.

<BZL-301

(SA2694-001) in the

grease

except

for

those

which

grease

<BZL-301 (SA2694-001)>

unit (SA2693-001) to

grease

in the blue

are

blue

in the

indicated

use

for

2935M

2.

Applying

Follow

Insert

(1) all

in

the

1.

Tum

2. Remove

3. Apply

4. Tighten

grease

the procedure belowto apply greaseto the places indicated byarrows on the next page.

the

tip of

the

nozzle

the

part.

power

the

way into

screw

the

switch to "OFF".

(2). (Refer to the next

greasetoeachofthe

the

screw

(2) to

(2)

hole

holes

pushinthe

until

grease.

page

the

Apply letting it spill

for greasing locations.)

grease

Grease

grease

without

out.

overflows slightly.

5. Use a cloth to wipe

(2).

6. Apply

7. Carry

NOTE:

•

'

• When using the

(Store

the

its lubricating

Once tube,

The

nozzle

grease

out

the

grease

attach

the

grease

should be

first.

the

tube

away

remaining inside

performance.)

to all locations

reset

tube

cap

grease

away

procedure given on the next

has

securely

usedasquicklyaspossible.

carefully

Tighten

the

any

excess

shownonthe

been

opened,

and

store

again, remove

once

the

tube

may

the

grease.

grease

the

tube

any

old

tube

has

deteriorate,

screwtopush

from around

pageinthe

page.

the

nozzle from the

in a cool

grease

been

dark

from inside the

opened,

and

this

in

2936M

the

screw

same

way.

place.

otherwise

may

affect

2937M

T-8400A,

8700A

48

5.

APPLYING

GREASE

Turn

the

screw

(1)

canbeseen.

Use

the

tip of a screwdriver or similar to

apply 5-10 mm

block

slider

(2).

machine

pulley until

beadsofgrease

2938M

the

to the slide

Pour

oil

<Resetting

B888

"(• A)

Into

the

oil

coveratthe

the

cumulative

zOrEflSEUPz

®

(3

® ®0 0 b

tS)

(!

I) ((

operating

(S) (S)

same

time.

tlme>

.1©

(2

« •)e

^1© 1© 1©

€

5) (J

))(•j) (;

5-10mm

4

places

at top,

and

bottom, left

of

the

slide block (3)

After

the

grease

procedure

applications.

1. Turn

2.

3.

the

main display (1)

Press

the

changetostitch

Press

and

The lock icon (4)

released.

4.

Press

the

appearingreeninthe

(xxx

represents

5. Press the rightmost V key

"0".

6.

Press

1

and

more.

The

buzzer

display (1) will

(This

completes

has

been

applied, carry out the following

to

reset

the

cumulative time

power

switch to "ON"."GREASEUP"

and

the

buzzer

will

RESET

hold

FUNG (Function) key (5). "n.134 xxx" will

hold

will

key (2).

number

the

change

the

display

LOCK key (3) for 2

will

switch off

main

display (1).

time between

ENTER

make

a long

to stitch number display

reset

procedure.)

The

main display (1)

mode.

seconds

and

grease

(6).

The

"xxx"

key (7) for two

beep,

and

right

between

will

sound.

or more.

the lock

applications.)

will

change to

seconds

then

2939M

grease

flash in

will

the

mode.

will

be

or

main

2940M

49

T-8400A,

8700A

2139M

__6^^RgASEAPPLICATI0N

6.

GREASE

APPLICATION

AND

LUBRICATION WHENDIASASSEMBLING ANDREPLACING PARTS

AND

LUBRICATION

WHEN

DISASSEMBLING

Be sure to wear protective goggles and gloves when handlingthe

into your

0

Furthermore, do not

diarrhea.

Keep

the

eyes

or onto your skin, otherwise inflammation

drink

the

oil

outofthe

reach

of children.

AND

A

REPLACING

CAUTION

lubricating

can

result.

or eat the grease under any circumstances, as they can cause

When disassembling parts and reassembling parts during replacement, apply or

places

marked

with

O.

GREASE

BZL-301

(SA2694-001)

Blue

NOTE:

• Use only the

tube>

specified by Brother.

• Do not

white

• Do not

tube

for

use

tube

use

any

grease

the BZL-300 (SA2355-001)

withthis sewing machine.

the

models

with "Use only

specified by Brother".

30

mm

2934M

Purchase

applying

the

grease.

PARTS

oil

and grease, so that they do notget

with

BZL-301

the

grease

<BZL-301

(SA2694-001)

except

grease

unit

or lubricate

(SA2694-001) in the

for

those

which

<BZL-301 (SA2694-001)>

(SA2693-001)

vomiting

the

greaseinthe

grease

in the blue

are

to

and

following

blue

indicated

use

for

Filling

means

filling

places

suchasgrease

Numbers in

warning.

No.

Upper

r

T

Needle

3*

4*

5*

6

7

8"

9

10

11

12

the

table

marked with * indicate

Applying or filling locations

shaft

mechanism

Meshing

take-up

Meshing

part

support

part

of thread take-up lever

shaft

of thread take-up lever

take-up slide block, thread take-up slide block

needle

rod

Meshing

(upper)

Meshing part of needle bar Meshing part of needle

and

Meshing

connecting

Meshing

connecting

Meshing

bearing

Both

bar

and

needle

bar

rocking

slide

sidesofneedle

connecting rod,

bar

crank

mechanism

partofneedle

block

slider

partofneedle

rod

slide

block

part

of needle

rod

partofneedle

bearing

bar

and

needle

shaft

bar

and

needle

bar

connecting rod slide block

bar

clamp

bar

clamp

bar

rocker shaft

bar

rocker

case

rocker

shaft

Meshing part of outside of needle bearing

arm

hole

sumps

places

bar

needle

bar

and

shaft

thrust

of meshing

were

and

thread

and

thread

connecting

bar

base

(lower)

needle

bush

L

and

needle

washer

case

partsorgaps

grease

and

bar

and

between bearing.

is applied

(Dry)

O O

o o o

o o

o

o o

when

the

operation

Specifications

Semi

dry

o

panel

Dry... Option specifications

Minimum

lubrication

O O

o

o o

gives

Apply

O

o

o o

o

o o

o

a greasing-up

Fill

o

0

o o

T-8400A,

8700A

50

6.

GREASE

APPLICATION

AND

LUBRICATION

WHEN

DIASASSEMBLING

AND

REPLACING

PARTS

No.

Meshing part of needle

13

Both

14

15

16

17

Presser

18*

19

20

21

sidesofbush

Meshing part of needle

rocker

Meshing part of needle

bush

Both

sidesofneedle

foot

mechanism

Meshing part of needle Meshing part of needle

Meshing

Meshing part of

Applying or fillinglocations

bar

R

bar

link

shaft

bar

bar bar

partofpresser

presser

bar

rocker

Meshing part of tension

22

presser

shaft

Sloping

23

Meshing

24

screw(2places)

Meshing part of knee lifter lever

25

places)

Feed

mechanism

26

Meshing

Meshing part of level feed eccentric wheel

27

bearing

Meshing

28

shaft

Meshing part of feed regulating

29

30

Sliding

Feed

shaft

31*

Meshing

32

arm,

Meshing

33*

and

Rotary

hook

34*

Meshing part of

Threading

35

Meshing

bar

lifting

surfaceoftension

partofknee

partofreverse

part

of connecting rod

and

shoulder

parts

of feed regulator

mechanism

partoffeed

part

of feed

and

both

sidesofthrust

part

of feed

feed

bar

slide

mechanism

partoftension

lever

screw

block

opener

lifter

lever

bar

and

link

release

and

release

connecting

and

slide

rocker shaft and bush R

rocker link

link

and

presser

and

presser

guide

lifting

release

presser

and

bar

bush

bar

bush o o

bracket

crank

and

plate assembly,

bar

needle

zigzag link

arm

lifting lever

plate

rod

and

shoulder

and

shoulder

screw

shaft

and

needle

and

eccentric

stud

and

arm

and

stopper

feed

bar

shaft

and

feed

rocker

washer

block

and

feed

bar

feed

lifting

eccentric

shaft

and

opener

link

bar

and

arm

hole

bar

wheel

base

fork,

wheel

Specifications

Semi

(Dry)

O O

o

o o

o

o o o

dry

O o

o

o o

o

o o o o o o

o o

(2

o

o o

Minimum

lubrication

O O

o o

o

• o

Apply

o

o o o o

o o o o o o o o

o o o o

o

o o

Fill

o

o o

o o o

o

o o

o o o o

• For sewing machines withthread trimmer, refer to the

following

page.

• For sewing machines withoutthread trimmer, after installing the parts, apply grease to the locations specified on pages 46

and

49.

51

T-8400A,

8700A

e^GREASE^PPLICATION

AND

LUBRICATION

WHENDIASASSEMBLING ANDREPLACING PARTS

Thread trimming

No.

Quick

reverse

1

Meshing part of solenoid lever shaft and solenoid lever assembly

2

Sliding parts of solenoid lever assembly and pin

Rotary

hook

3 Meshing parts of movable knifelever L and R and rotary hook

4

Sliding parts of movable knifelever and rotary hook

5 Sliding parts of

Thread

trimmer

6

Meshing part of thread trimmer connecting rod L and R and shoulderscrew

7

Rounded contact parts of round joints Land R

8 Meshing part of driving rod plate and main lever assembly

9 Meshing parts of driving rod and bed

10

Meshing

11

Meshing parts of main lever assembly roller

groove)

12

Left

13

Meshing

14

Meshing

15

Meshing parts of solenoid lever and plunger pin

16

Meshing parts of tension

sewing

mechanism

parts

side

of thread trimmer

parts parts

machines

set

screw collar and rotary hook

of main lever

of solenoid of solenoid lever

only (T-8422A,8722A)

shaft

and

cam

(around whole of tension release cam)

lever

shaft and

shoulder

release

lever

Application

main lever

and

solenoid lever

assembly

base

thread trimmer

screw

and shoulderscrew

locations

base

cam

(around whole of thread trimmer

can

Apply

O O

o

o o

o

o o

o

o o

o

o o

<Lubrication>...

Use only

* Ifthis

Thread

Tension

the

type

No.

trimmer

1 Sliding parts of tension

2 Sliding

release

3

Between

After installing

Thread

lubricating oil (Nisseki Mitsubishi Sewing Lube 10N; VG10) specified by Brother.

of lubricating oil Is difficultto obtain,

mechanism

parts

mechanism

inner

the

parts, apply

trimming

sewing

release

of main lever roller

and

outer

tension

grease

machines

the

recommended

only

Lubrication

(T-8422A, 8722A)

oil to

locations

lever assembly roller and shaft

and

shaft

release

wires

to the locations specified on

use

is <Exxon Mobil

pages46and

49.

Essotex

SM10; VG10>.

Lubricate

0 O

o

T-8400A,

8700A

52

7.

SWITCHING

7.

FROM

NEEDLE

SWITCHING

FEED

TO

FROM

LOWER

FEED

NEEDLE

A

CAUTION

FEED

TO

LOWER

Switching

between upperfeed and lowerfeed shouldonlybe carried out bya

properly

qualified

0

Turnoffthe powersupplyand disconnect the powercord beforecarrying outthis procedure. Otherwisethe

*

will

A

operateifthe

When using a clutch

motor's inertia. Wait until

treadleispressedbymistake,

motor,

the

motor

the motor

rr-y

will

keep

stops

fullybefore starting work.

3102M

(2)

(1)

©

which

turning

could

result

injury.

even after the power is switched off as a result of the

1.

Remove plate

2.

Change

rocker link (1) from (A)to (B).

(Be careful not to pullout the bolt (2) too far, othenvise

washer

3. Remove

timing pulley D (4) in the turning direction. Also loosen

screw

the

needle

and

presser

the

(3) may fall down.)

the

(6) on

foot).

position of

screw (5) (sharpened tip) at the front of

the

far side.

feed

gauge

the

bolt (2) of

technician.

parts (feed dog,

the

needle

machine

needle

bar

the

53

Do not fully the

bolt (2)sothis

does

not

fall

remove

down.

T-8400A,

8700A

(7) >—(5)

6)—1

A-

3103M

7.

SWITCHING

FROM

NEEDLE

FEED

TO

LOWER

4. Turn timing pulley D (4) forward 180 degrees with respect

to the lower shaft (7), (5) into the hole (8) that

(The

screw

(6) at

(8).)

the

and

then insert the removed screw

does

not

have

a screw inserted.

far

side

will be in the far

screw

5. Tighten the screw (5) (sharpened tip) so that it fits into the

screw

stop

groove in

the

lower

shaft

(7).

6. Tighten the screw (6) that was loosened in step 3 above.

7. Install the lower feed gauge parts (feed dog, needle plate

and presser foot) and carry out the respective

adjustments.

* Ifthe needle

does

not go into the needle hole for the

lower feed needle plate, adjust the position of

needle. (Refer to "4-7. Needle drop forward/back

position".)

8. Carry out the adjustments in "4-8. Needle

timing".

9. For

the

on

the

T-8421A,

operation

8422A

panel

and

to "0".

8722A,

and

set

function No.

rotary hook

(Refer to "8-4. Function settings".)

FEED

hole

the

34

T-8400A,

8700A

54

8. REPLACING

8.

REPLACING

GAUGE

PARTS

(CHANGING

GAUGE

THE

NEEDLE WIDTH)

PARTS

(CHANGING THE NEEDLE

A

CAUTION

WIDTH)

Replacement of gauge parts should onlybe carried out bya qualified technician.

0

Turnoffthe

will

operate ifthe treadle is pressed by mistake, which could result

When

motor's inertia. Wait until

Gauge parts should only be replaced with parts specified by Brother.

power

supplyand disconnect the powercord before

usingaclutch

motor,

the

motor

will

keep

stops

fullybefore starting work.

3104M

turning

even after the

1.

Remove

2. Remove the needle clamp (1) by turning it in

of

the

3. Raise

4. Remove the

5. Remove the needle plate (4)

6.

Tilt

back

carrying

injury.

the

arrow.

the

presser

the

outthisprocedure. Otherwisethe machine

powerisswitched

needle

and

the

foot (3) using

presser

machine

foot (3).

head.

off as a result of the

slide

plate.

the

liftinglever (2).

and

the

feed

dog

the

(5).

direction

3105M

<

Moving

• If

one

Carry

position".

* If

Carry

position".

1. Install and be careful not to overtighten.)

2.

Install

3. Install (Referto "4-15. Installing

4. Turn into

(Loosen adjust.)

moving

side

out

moving

out

the

rotary

hook

the

stitch

width

steps

2 to 6 in "4-11. Rotary hook

the

stitch

width

steps

3 to 6 in "4-11.

needle clamp (1). Tighten to approximately 3 N,

needle.

feed

dog

(5).

the

machine pulley

middle of

the

screw

the

needle

(6)

and

base

>

more

than

approx.1mm

approx.1mmtoone

Rotary

feed dog".)

check

that

the

needle

hole in

the

feed

dog

turn

the

needle

hook

(5).

bar

to

base

side

base

drops

(7) to

3106M

55

T-8400A,

8700A

5. Readjust the needle and rotaryhook timing.

(Referto

6.

Move

• Ifmoving

"4-8.

Needleand rotaryhook

the

rotary

hookbase to adjust the clearance betweenthe needleand the

the

stitch width more

Carryout steps 7 to 11 in"4-11. Rotary hook base

timing".)

than

8. REPLACING GAUGE PARTS (CHANGINGTHE NEEDLE

rotary

hook

tip.

approx. 1 mm to

one

position".

side

WIDTH)

• Ifmoving

Carryout steps 8 to 11 in"4-11. Rotary hook

7. Retum the machine head to its original position.

8. Instal the needle plate (4) and the presserfoot (3).

9. Ifitis a thread

(Refer to "4-25. Thread wiper".)

the

stitch

trimming

width

approx.

sewing machine, adjust the thread wiper.

1 mmtoone

base

side

position".

T-8400A, 8700A

50

9.

FUNCTION

9.

FUNCTION

9-1.

Maximum

1

SETTINGS

fT-8421A.

8422A.

8722A)

SETTINGS (T-8421A, 8422A, 8722A)

sewingspeed and start backtack sewing speed setting methods

Ifthe

LOCK

operations.

2232M

(Current setting)

key icon (1) Is on, release the

The

main display

green

display.

will

lock

change

before

carrying

fromanorange

out the

display to a

following

Maximum

3108M

Start

backtack

Maximum sewing

sewing

speed

IA,'A,

sewing

setting

speed

u n

1

uu

setting

speed

f?

u

Start

©MAX

t Q n n

f a

Example:

3,500

backtack

uu

rpm

sewing

speed

The maximum sewing

220

rpm to

the

maximum sewing

for

the

head

detector

If all

numbersinthe illuminated, sewing speed

thatisset

The

start

backtack sewing

from

220

rpm to

(The factory default setting is

will

here

1,800

speed

unit.

sewing

be carried

when

2235M

rpm.

can be

speed

control display (2)

the

treadle is fully

(2)-^

speed

canbeset

1,000

rpm.)

set

to a

that

has

outatthe

brother

3107M

speed

from

been

maximum

depressed.

to a

speed

set

are

Example

1,600

rpm

When

NOTE:

57

When

the

used.

Press

operations

main display is

the

MAX

key

can

thenbecarried

green,

once

normal key

more to

out.

operations

clear

the

suchasthe

sewing

T-8400A,

and

returnstothe

speed

8700A

sewing

display

start

backtack key

starts,

orange

and

the

return to

sewing

display.

and

the

speed

display

fixed stitch key

orange

display. Normal key

3109M

disappears

2159M

cannot

be

9-2.

Using

the

LOCK

9jFyNCTJONSETTjNGSjT^421Aj8^

key

9-3.

/T^

A

A A

y y

Setting

(2)

y

(3) (4) (5) (

the

DIP

switches

2212M

When the power switch Is turned on, the LOCK key (1) turns

on. (The Icon (2) Is Illuminated.)

state,

the

In this

so

that setting values cannot be

• FUNG key (3)

• ENTER key (4)

•

MAX

key (5)

<Releasing

Press

down

The

icon (2) willswitch off

<Setting

When

the

(1) for 2

The Icon (2) will Illuminate

operations

seconds

following

the

lock>

the

LOCK key (1) for 2

the

lock>

Icon (2) Is switched off,

or more.

will

become

three

and

disabled.

key operations

changed

seconds

the

lock will be

press

down

and

the

are

accidentally.

or more.

released.

the

LOCKkey

above

three key

disabled

Walt at least 5 minutes after turning off the power switch and disconnecting the power cord from the wall outlet

before opening

A

severe

Injury.

Presser

1

returnedtothe

trimming

Presser

2

depressedtostep1.(See

3

4

(NOTE 1) Once the

(NOTE 2) The treadle unit should (NOTE 3) When

foot position

foot lowering

while the machine Is

If

settoON,

display.

the

face plate of

when

neutral

knee

set

to ON, treadle operation Is disabled,soItshould always be left at OFF.

position

when

lifterswitch Is

the

messages

A

the

control box. Touching

Control

Box

the

treadle

after

the

treadle

NOTE

2)

stopped;atthis time, only

alsobeadjusted when using this function. (Refer to

"ci' P

thread

used

Is

to lower the

DANGER

2237M

4"

Presser

(See

Enabled

Disabled

Spare

Always

presser

the

(green)

ON

OFF

ON OFF

Sb

areas

where

footIslowered.

foot Is kept raised.

NOTE

1.)

settooff.

foot,

knee

lifterIs able to raise and lower

the

(See

treadle

and"£rr

high voltages

(Export

specification)

(Japanese

NOTE

3.)

can

not be

used

page

83.)

lOI"(orange)

are

present

specification only)

to raise the

the

presser

will

flash

can

foot.

alternatelyInthe

result In

presser

foot

T-8400A,

8700A

58

9.

FUNCTION

9-4.

Setting

1

Selecting

SETTINGS

functions

the

function

(T-8421A.

LOCK

number

2238M

Function

8422A.

Ifthe

LOCK

operations.

Ifthe

MAX

number

no.

Setting

8722A)

key Icon (1) Is on, release the lock before carrying out the

key Icon (2) Is on,

display (orange).

•

value

press

The

main display

Refertothe

function

that

the

MAX

key to return the main display to stitch

will

enabled.

"Function

you would like to

changetogreen

List"toselect

change

the

and

function setting

the

number

setting

following

2239M

for

for.

the

Changing

a IH

the

setting value

Example:

Function

Example:

Setting

o

14

1

no.

value

Refertothe

within

The then

the

The

main display will retum to

"Function List" to

the

setting range.

buzzer

setting willbe

will

sound

(orange).

change

the

for approximately 1

accepted.

the

stitch

setting

second,

number

to a

2240M

value

2241M

and

display

(Press

for2secondsormore)

NOTE:

• Ifyou depress the treadle before pressing the ENTER key, the main display

will

return to orange

willnotbechanged.

• If you change the function number after changing the setting value but before pressing the ENTER key, the setting

value

will

not be changed.

You need to press the ENTER key for

59

each

function number for the setting to be accepted.

T-8400A,

8700A

and

the setting value

2242M

9-5.

Function

^FUNCTJONSETgr^^

List

Function

No.

11

No.

0-13

Initial

0

(degrees)

0

(degrees)

value

(N0TE1)

12

13

(NOTE 1) Iffunction No. 69 is (NOTE 2) *... (Altemate):

Presser

foot

will

The

not

presser

(Momentary): The

Setting

range

-10-20

(degrees)

-10-10

(degrees)

0-1

0-4

0-1

set

to "3", operation is

drop

ifDIP switch 1 is

foot rises or drops

presser

foot rises only while

Setting

details

Needleupstop

Needle

down

Depressing

0: Disabled (depressing

-10-^

Becomes

stop

•10

Becomes

fonA^ard

position setting

higher

position setting

lower

when

depressed

fonA/ard

backward (thread trimming)

is enabled after returning to neutral

position)

1:

Enabled

Power

supply voltage drop check (reset detection) function

0:

Not

used

1:

Used:

Buzzer

0:

Used

1:

Not

(Do

not

"Err6"is

(electronic

used

change

displayed

sound)

this

whenavoltage

for panel operation

setting.)

Needle penetration up operation

0:

Used

1:

Not

used

Backtack

0: Limited by

1:

End

0:

sewing

Not

limitedbysewing

backtack

Separate

setting from start backtack sewing

speed

sewing

speed

control key

control

key

1: Settingfor start backtack sewing is used

Option

actuator

operation

setting

0; Half stitch correction sewing

1; Single stitch correction sewing

2: Single

3:

4: Single

5:

Thread

Presser

reverse

stitch correction sewing

trimming

end

backtack cycle cancel

foot lifter rises (alternate*)

(reverse

6: Presserfoot lifterrises (momentary*)

Presser

0:

1:

Presser

0:

1:

Presser

Presser Presser

foot

foot foot

status

drops

does

status

does

lifts

when

treadleisreturned

(See

NOTE 2)

not drop

after

treadle

not

lift

stopsatneutral

enabled.

set

to OFF.

each

time

the

option actuator is

the

option actuator is being pressed.

pressed.

Becomes

drop

occurs

speed

feed)

to neutral

•

20

lower

•

10

higher

is possible

after

thread

2243M

2244M

trimming

T-8400A,

8700A

60

g^UNCTIONSETTINGSa

Function

No.

14

15

16

17

18

19

20

No.

14-27

Initial

value

0

3 (minutes)

0

20

(ms)

50

(ms)

50

(ms)

Setting

0-30

10-200

range

0-1

(minutes)

0-2

(ms)

Actuator

Setting

function

details

0: Reverse stitch switchduring operation, correction sewing switch when

stopped

1:

Thread

trimming

switch

Slowstop control when treadle is returned to neutral

0: Slow

1: Overtime

0:

1-30: Machine stops after continuous operation for

Correction sewing function

Above

Not

stop

control without

controlisnot

function

used

displayed.

used

step

(See

operation

NOTE 3)

set

time, and "Err 8" is

0: Halfstitch correction sewing/Single stitch correction sewing 1: No correction sewing/Single stitch correction sewing

2: Reverse stitch (reverse feed) correction sewing/Single stitch correction

sewing

ser

Thread

Ttiread wipiiiy

wiping

Motor

and

pres

foot liftoperation timing after thread trimming

No.18

^N0.19

1

2245M

. • ^

lifting

Needleupstop

•

|vjo.32

(fu'ly

ON)

21

22

23

(NOTE

24

(NOTE

25

(NOTE

26

27

(NOTE

(NOTE 4)

(NOTE 5)

(NOTE 6)

Start

4)

5)

6)

0

0 (stitches)

0

0-99

0-1

(stitches)

0-1

backtack

0: Stitch

1:

Stitch

End

backtack

0:

Stitch

1:

Stitch

number

Stitch

number

Stitch

number

Speed

for moving to

0:

Decelerates

1:

Deceleratestoend

(Cycle

Continuous

0:

Stitch

1:

Stitch

sewing

number

A, B (N

A, B, A. B (N

sewing operation

number

C, D

C, D.0,D (N

G

H

1

to low

time

canbeshortened.)

backtacking

number

A, B, C, D

A, B x D

operation

stop)

end

backtack

speed,

then

backtacking

operation

times

stop

double)

end

backtacking

speed,

then

starts

end

backtacking

starts

3) The setting to the leftofthe"/"symbol is when the correctionstitch icon is off,and the setting to the right is when

the

Turn

turns

Stitch

correction

the

back

number

stitch

power off

on.

setting

iconison.

and

back on again when this setting is changed.

is

enabled

is

enabled

is

enabled

when

Function

No.

118

is

The

set

from

"1"to"3",

setto"2"or"3".

setto"3".

setting

will

be enabled after

the

power

61

T-8400A,

8700A

9.

FUNCTION

SETTINGS

J^8421A,

8422A

8722^

Function

(NOTE

(NOTE 7)

No.

28

29

30

31

32

33

34

35

36

37

38

39

No.

12)

13)

Operates

28-39

Initial

value

0

150

(ms)

0

300

(ms)

0

1

0

180

(seconds)

(3

minutes)

0

40 (ms)

12

when treadle is lightly

Settinq

0-1

0-3

0-500

(ms)

0-1

10-990

0-1

0-240

(seconds)

0-1

20-120

10-12

ranqe

(ms)

(NOTE 8) Adjustmentof Function No. 39 is

(NOTE 9) Adjustment of Function No. 38 is

(NOTE 10) Duty during chopping (NOTE 11) Duty during chopping

(NOTE 12) Only (NOTE 13) Only *... (Alternate):

enabled

(Momentary):

when when

The

canbechanged canbechanged

Function No.35is Function No. 35 is

presser

foot rises or

foot rises only while

Settinq

Feed

direction

0: Quick

normal

1: After

(See

when

stopping immediately after start backta

reverse

stopping,

NOTE

solenoid turns off and

feed

direction

quick

reverse

solenoid

7) j

Actuator function when sewing machine is

0:

None

1:

Presser

2:

Presser

3:

Quick

Delay time until motor

and

Stopping during

foot lifter rises (alternate*)

foot lifter rises (momentary*)

reverse

device

starts

the

presser

footisraised

start

backtacking and

operates

operating when using automatic

when

0: When treadle is returned to neutral,

stops,

and

the

operation

1: When

treadle

is returned to neutral, stopping is possible while start

backtacking is in progress,

the

to

speed)

Presser

treadle

foot

depression amount (low

lifter

solenoid

speed

and

fully ON

Operation during pleat sewing setting

0:

Reverse

1: Fixed stitch

(fixed

Changing twin

0:

Lower

1:

Needle

Presser

0: Automatic

1:

Manual

Presser

0: No timer function

1-240:

Automatic

0: Solenoid

1:

Pneumatic

Delay time for

command

Voltage

presser

pressed

sewing

stitch

feed

foot

soft

mode

foot

lift

Presser

presser

type

detection

foot

drop

when

Function No. 31 Is

operation

sewing

sewinq

needle

down

(See

time

foot

foot lifter

(See

presser

constant

command

when

operation

recall

when

function)

lock stitcher feed specifications

mode

(See

NOTE 8)

NOTE

9)

(does

not drop)

drops

after

set

type

NOTE 10)

NOTE

11)

foot lifter solenoid to tum on after

for

presser

set

necessary.

using Function No. 115. using Function No. 116.

set

to "1".

set

drops

to "0". If

each

the

set

time

option

to "10",

the

option

actuator

responseisfastest

actuatorispressed.

is being

sewinq

is the

the

time

actuator

time

to "0".

details

stops

in 1

turns

OFF

stopped

starts

speed

during start backtacking

start

backtacking finishes

start

backtacking (constant)

start

backtacking

speed

up to

switch is ON

actuator

foot

switch is ON

lifter

solenoidtotum

and

operating

pressed.

eking

III

aIIb

II

11

a|1b

II

presser

and

speed

corresponds

start

backtacking

presser

foot drop

on after

noiseisgreatest.

2246M

lifter

then

speed

T-8400A,

8700A

62

9.

FUNCTION

SETTINGS

fT-8421A.

8422A.

8722A^

Function

No.

40

41

42

43

44

45

46

47

48

47

48

49

51*

52

53*

54*

No.

40-54

Initial

80

2

(needles)

value

0

(ms)

0

10

1

(NOTE 14) Setting Is only (NOTE 15)

*...

Presser

pedal Settings

foot lifter pedal operation is not included. In

takes

indicated

**... (Alternate):

(Momentary):

Setting

1-99

0-500

0-100

range

0-1

(ms)

0-1

(needles)

0-2

enabled

when

priority.

with"*"are

The

puller

risesordrops

The

puller rises only while the

Operation

Setting

after knee switch is used to raise and

details

lower

presser foot (See

NOTE 14)

0:

Presser

backward

1:

Above

Presser foot

foot cannot be raised

operationispossible

lifting

when treadle is depressed backward to 1st step after

and

lowered by depressing

returning to neutral

0:

Possible

1: Not

possible

Operation when treadle is

depressed

backward

0: Thread trimming operation

1: Thread trimming operation disabled (presser foot is raised when treadle

is

depressed

backward)

Depressed backward operation after treadle is returned to neutral and

needle

stops

in the up position

0: Singlestitch issewn and then the thread is trimmed (lockstitchers)

1: Thread wiping operation when needle is stopped in up position (chain

stitchers)

Operation when Standing operation variable

0: Sewing

1: Sewing

speed)

Delay

time

speed

corresponds

speed

corresponds to sewing

from

standing

to treadle

pedal

tumingonuntil

speed

pedal is on

depression

speed

amount

control key setting (constant

motor

starts

operating

Operation during standing operation when AUTOfunction is on

0: Sewing

1:

Above

Operation during standing operation 0: Operation

off

1:

Above

pauses

functionisnot

when presserfoot lifter pedal is on (operation pause)

stops

when high

used

when

AUTOfunction is on

speed

pedal turns back on, and restarts when

Thread trimming pedal function after thread trimming during standing

operation

0:

Presser

1:

Above

Operation during standing operation

0: Operation

off

1:

Above

Thread trimming pedal function

foot

canberaised

operation

functionisnot

stops

not

when high

used

and

(onlv

speed

lowered

possible

using

when

AUTO function is on

presser

foot

lifter

pedal turns back on, and restarts when

after

thread trimming during standing

operation

0:

Presser

1:

Above

Alternate standing operation pedal and treadle operation

foot

canberaised

operation

not

used

and

(onlv

lowered

possible

using

presser

foot lifter

(See

NOTE 15)

0: Treadle operation is disabled after standing operation pedal is

1: Treadle operation

used

(alternate

Correction stitch sewing using

can

also be

operationispossible)

used

actuator

after standing operation pedal is

switch afterthread trimming

0: Not possible (switch operation disabled)

1:

Possible

Numberofslow

Count units for stitch

start

stitches

counter

display

0: No counting operation

1-100:

Display

Operation

0: Starting

counts

downbynumberofstitches

when

stitch

counter

using

treadleisenabledasnormal

warning

occurs

set

("!"

icon is illuminated)

1: Starting using treadle is disabled (thread trimming by depressing treadle

backward is possible)

2: Starting

neutral

DIP switch 1 is

enabled

each

when

time

using

and

operation

set

to OFF.

the

poweristurned

the

presser

treadleiscompletely

stops

the

caseofsimultaneous

off

and

foot switch is

foot switch is being

disabled

then

back

pressed.

once

operation,

on.

treadleisreturned

the

standing operation

the

pedal)

used

treadle

to

63

T-8400A,

8700A

9JUNCT10NSEnjN^^

Function

No.

47-68

Initial

value

Setting

range

Operation after treadle is depressed backward or knee switch is operated

55

(NOTE 16)

0

0-1

when

presser

0: When treadle is returned to neutral,

1;

When

Function for preventing needle bar operation when treadle is accidentally

depressed

56

0

0-1

backward 0:

Used

1:

Not

used

Operation when treadle is

57

(NOTE 17)

0

0-1

is

0: 1:

raised

Presser Presser

Presser

58

0

0-1

0:

1:

Not

Used

used

Presser

59

60

0 (ms)

0-150

0-99

(ms)

(When Function No. 58 is

Highest

61

62

(NOTE 18)

0

0-1

0:

Not

used

1:

Used

Thread 0:

0

0-1

Thread

1;

Thread

63

64

(NOTE

0

2

(T-8422A

-DD3)

0

0-1

0-2

(Other)

65

18)

150

(ms)

10-500

(ms)

0: Not

position)

1:

Used

Thread

0 : 1

1 :

1/2

2 :

1/4

[Do

not

Delay time until reverse operation starts during highest needle position stop

operation

Presser

66

(NOTE 18)

0

0-1

0:

1:

Presser

19)

Highest needle position stop position setting

67

(NOTE 18)

68

(NOTE 20)

(degrees)

0

(NOTE 16) Setting Is only

(degrees)

enabled

-20-20

Seam

0-1

0: Operation

1:

Operation

when DIP switch 1 is

matching

(NOTE 17) Setting is only enabled when DIPswitch 2 is

foot is

raised

treadleisreturned

Setting

to neutral,

details

presser

foot is raised

foot is

forward when it is returned to neutral after being

footislowered footisnot

lowered

foot soft up function

(Function

No.59and

depressed

No.60mustbeset.)

forward to

1st

step

foot soft up timersetting

set

to "1")

1 No.59 1 No.60 1 No.32

needle

wiping operation during

trimming timer

used

trimming gain adjustment

change

position

wiping

occurs

stop

after

operation

(Thread trimming is off

(Timeisset

using

this setting.]

foot lifttiming during

footisraised

after

foot is raised before

-20

Becomes

lower

function during

does

not stopwhen switching cloth feed direction

momentarily

set

to ON.

set

to ON.

stops

operation

highest

needle

thread

Function

highest

needle

automatic

when

needle

position

stopsinhighest

trimming,

when

No.

needle

barisraised

0 •

and

needle

73)

position

bar

liftoperation

Becomes

then

barisstoppedatthe

stop

backtacking

switching

cloth

lowered

depressed

when

presser

(fully

ON)

stop

operation

position

needle

barisraised

operation

starts

(See

20

higher 2248M

feed

direction

foot

2247M

NOTE

up

(NOTE18) Setting is enabled when Function No. 61 is

(NOTE19) Operation is disabled when FunctionNo. 62 is

(NOTE

20) Used when you would like to match the seam accurately during automatic backtacking. Use Function No. 78 to

set

the stop position

and

Function No. 79 to change the time before restarting.

set

to "1".

setto"1".

T-8400A,

Presserfoot is raised after needle bar is raised.

8700A

64

9.

FUNCTION

SETTINGS

(T-8421A.

8422A.

8722A)

Function

<When

Connecttoconnector

No.

69

No.

set

69

Initial

value

0

asastitch

CN9

Setting

counter

CN9onthe

range

0-3

actuator>

control

circuit

stitch

Stitch

The stitch counterwarning LED illuminates when

(This is

When

(This is

the

same

functionasthe"!"

stitch

counter

same

operationasthe

icon in

actuatorispressed,

RESET

Actuator (option) function

0:Nofunction

1:

Stitch

counter

2: Sewing

3:

Option

board.

counter

actuator

counter

warning LED

the

stitch counter display

the

operation panel icon display.)

treadle

key on

operation

the

operation panel.)

speed

actuator

is possible.

Setting

reaches

details

2249M

"-5".

<When

Connect

setasa

the

sewing

switchestoconnector

CN11

speed

actuator>

CN11onthe

control

? ? ?

Low speed Medium

• When the low

Function

No.

When the medium

Function

No.

speed

122.

121.

switch

switch is

speed

pressed,

switch is

speed

switch switch

pressed,

• When the high speed switch is pressed, the sewing

the

MAX

key.

<When

Connecttoconnector

setasan

option

CN9onthe

CN9

actuator>

control

circuit

High

the sewing

board.

circuit

speed

board.

becomes 1,000 rpm. The

speed

becomes 3,000 rpm. The speed

returns to the maximum sewing

speed

can

be changed by setting

can

be changed bysetting

that has been

set

2250M

using

Option

Actuator

Set

the

operation using Function No. 11,

65

T-8400A,

8700A

2251M

9.

FUNCTION

SETTINGS

fT-8421A.

8422A.

8722^

Function

No.

70-72

Initial

value

Setting

range

Option output setting

0:

Puller

1: Needle cooler (synchronized output during operation)

70

(NOTE 21)

6

0-6

2: Air

3:

Condense

saving

4: Chain stitch thread trimming (thread wiping)

5:

Pneumatic

6:Nooutput

71

(NOTE 22)

72

(NOTE

22)

0

(needles)

10

(seconds)

0-99

(seconds)

(needles)

5-30

Number of stitches from sewing

0: Synchronized with

1-99:

Pullerislowered

Time until puller is lowered

(NOTE 21) The factory default setting is for no output,sothe

on

the

control

(NOTE 22) Setting is

<When

•

• During sewing,

• The time of 10

settopuller>

When

the

foot

lifter.

sewing machine is stopped,

the

seconds

• Function No. 71

circuit

board.

enabled

when

Function No. 70 is

puller is only raised when

can

be changed bysetting Function No. 72.

canbeusedtoset

the

set

to "0".

the

puller is lowered after 10

the

reverse mechanism

numberofstitches

raised (in synchronization with the automatic presser foot

this

operation

occurs.

wiper

presser

after

output must be

seconds

Setting

foot lifteroperation

the

set.

details

start

until puller is lowered

set

numberofstitchesissewn

Output is from pins

2-4

of connector CN15

in synchronization with the automatic

operates.

until

the

puller is

lifter)

whilethe sewing machine is stopped after thread trimming,

lowered

after

sewing

starts.Ifthe

presser

puller is

<When

settoneedle

cooler

(synchronized

output

during

operatlon)>

• Output is synchronized with motor operation.

Motor

_J

saving>

<When

Option

settoair

• Output only occurs at the sewing start and the sewing end. A material

sewing

• Function No. 108 is

set

• The number of stitches at the sewing end is set by

• The delay time after thread

end.

are

being

sewed

edgeofthe

material is

position after the

usedtoset

the

number of stitches at the sewing start. Output only occurs while

after sewing starts.

fixed

stitch number E at the operation panel. Output occurs when the

detected.

trimming

edge

of the material is detected, output turns offwhen the needle stops.

Motor

Option

until

output turns off is

1

1 1

set

using Function No. 112. Ifthe needle stops in the down

edge

sensor (S2) is required for output at the

the

number of stitches

22S2M

Material

Needleupsignal

edge

sensor

signal

mnnnn

No.108

1

!

T-8400A,

:innnni~

Fixed

stitch

number

8700A

•

E

•

2253M

66

9^UNCTI0NSEniNGSjT^|^^

<When

• Start backtacking or

settocondense>

end

backtacking

must

• Forthesewingstart, set stitchnumberBto

• Forthe sewing end, set stitch number C to

Motor

Needle up signal

Option •

<When

• Afterthread trimming,

• Use Function No. 109

settochain

Operation

jn;:;

'Stitch

stitch

the

and

number

thread

A '

thread

No.

trimming

wiper signal is output.

110toset

be set.

"0".

Output

"0".

Output

(thread

the

timer operation.

will

occur

will

occur

Stitch

wiping)>

number

while

stitchesforstitch

while

stitches forstitch numberDare beingsewn.

Stop

number

Aare beingsewn.

i

D

2254M

Motor

Option

I

No.109

!

No.110

t

Needleupstop

<When

• Afterthread trimming, output is synchronized with

• Use Function No. 111

• When the

settopneumatic

and

presser

foot is lowered, option output

Needle up

wiper>

No.

stop

112toset

the

timer operation.

i

Motor

the

tums

automatic

off.

presser

2255M

foot lifter.

Presser

foot lifting

Option

-•K-

No.111

67

T-8400A,

No.112

8700A

2256M

9.

FUNCTION

SETTINGS

(T-8421A.

8422A.

8722^

Function

(NOTE

(NOTE 23) Setting Is

(NOTE 24) Setting is

No.

73

74

75

76

77

78

79

23)

24)

25)

26)

No.

73-79

Initial

90 (ms)

15

degrees

-30

degrees

-30

degrees

15

degrees

180

(degrees)

100

value

(ms)

enabled

Setting

50-150

10-500

when

range

(ms)

-345-345

(degrees)

-345-345

(degrees)

-345-345

(degrees)

-345-345

(degrees)

0-350

(degrees)

(ms)

Function No. 63 Is

Thread

Quick reverse solenoid on timing during start backtacking/continuous

backtacking

Quick reverse solenoid offtiming during start backtacking/continuous

backtacking

Quick reverse solenoid offtiming during end backtacking

Quick reverse solenoid on timing during

Pause

when Function No. 22 or No. 26 is

(NOTE 25) Setting is enabled when Function No. 68 is

turns

on.

(NOTE

26)

Setting Is

enabled

when

Function No. 68 Is

position.

When

the

<Settlngs

for

stopping time

Function

Nos.

has

74-77>

elapsed,

the sewing machine restarts automatically.

trimming on time

position

time

set

when

switching

when

switching

feed

to "1".

set

to "1".

set

to "1". The stopping position Is

set

to "1".

The

reverse

Setting

feed

direction

feed

details

end

direction

mechanism

backtacking

the

angle after the

switchesatthe

need

up signal

stopping

• If

the

values

are

becomes

direction.

faster. If the

• If the values are becomes

direction.

slower. If the

set

to values that

seam

set

to values that

seam

are

less than the initial value (- direction),

length immediately before switching occurs is short,

are

greater than the

initial

value (+ direction), the quick reverse solenoid on/off timing

length immediately after switching occurs is short,

the

quick reverse solenoid on/off timing

change

the setting to a value in the -

the setting to a value in the +

T-8400A,

8700A

68

a^UNCTjONSETTINGS^rj^^

Function

No. 80*

sr

82* 83*

84*

85*

86*

87*

88*

No.80-88

Initial

value

0

Setting

-7-7

-5-5

-6-6

-2-2

0-2

*... Settings indicated with" *"

With

the

treadle neutral positionasthe

backward direction

(Referto

page

are

- (minus) values,sothat the

84 for details.)

range

are

Treadle

Treadle Treadle

Treadle

backwardon(thread

backward

fonA/ard

forwardon(starting)

variable

high

1st

stepon(presser

speed

range

stepon(presser

range

Setting

trimming)

point

starting

reaching

foot

point

details

point

foot

lifting)

dropping)

point

Variable speed range starting point for standing operation variable

pedal

High

speed

range

enabled

0 point,

Treadle

0:

Constant

1:

Curves

2:

Curves

when

the

speeds

speed

curve

downward

upward

the

power is turned off

valuesinthe

accelerate

reaching

point for

standing

and

then

forward direction

or decelerate around

operation

Depression

back on.

are

+ (plus) values,

the

standard

variable

stroke

and

setting.

speed

pedal

2257M

thoseinthe

Speed

Treadle

Speed

A

Treadle

Speed

A

80=-7

\ 80=0

n Aif'

backward

80=7

stroke

-t

Neutral

83=-5

Neutral

83=0

83=5

85=-6

Depression

:

stroke

85=0

(ex. 1) Setting for Function No. 80

(ex. 2)

Setting

(ex. 3) Setting for Function No.

for Function No.

83

85

2258M

2259M

-ir

Treadle

backward

69

stroke

Neutral

Depression

stroke

T-8400A,

8700A

2260M

9.

FUNCTION

SETTINGS

rT-8421A.

8422A.

8722A)

Function

No.

90-107

Initial

value

220 (rpm)

90

91

92

93

94

96

98

99

101 102

103 104

105 106

107

(NOTE 27) This Is

(T-8422A-nn3)

220 (rpm)

(Other)

220

(rpm)

1400

(rpm)

220

(rpm)

3,000

(rpm)

1,800 (rpm)

MIL

(rpm)

(NOTE 28)

0 0

0 50 10

7

0

the

speed

settings.

upper

(NOTE 28) This setting is (NOTE 29) This is the

speed

upper

settings.

Setting

150-300

INCH-1,000

INCH-3,000

INCH-3.000

INCH-5,000

limitfor

read

limitfor

500-2,500

(rpm)

INCH-HIL

(rpm)

-

from

the

range

(rpm)

Thread trimming

Low

Stop

fDo

Slow

Start backtacking limit

End

Automatic

Maximum sewing

fDo (Do

fDo

fDo [Do

fDo

the

start backtacking

head

detector unit.

the

maximum sewing

speed

(INCH)

improvement

not

change

speed

(SLOW)

backtacking

speed

not

change

not

change

not

change

not

change

not

change

not

change

not

change

speed

(TRIM)

speed

(POS)

this

setting.)

speed

(EBT)

(AUTO)

speed

limit

this

setting.)

this

setting.)

this

setting.)

this

setting.)

this

setting.)

this

setting.)

this

setting.)

setting. Refer to

Setting

(SBL)

speed

details

(See

NOTE 27)

(MIL)

(See

NOTE 29)

page

57 for details on start backtacking

page

57 for details on maximum sewing

T-8400A,

8700A

70

^UNCTIOJJSETTJNGSr^B^^

Function

(NOTE

No.

108

109

110

111

112

113

114

30)

31)

32)

33)

34)

No.

108-114

Initial

0

(needles)

10 (ms)

0

0 (ms)

2000

0

(needles)

0

(needles)

value

(ms)

Setting

0-99

0-990

0-9900

0-99

range

(needles)

(ms)

(needles)

Numberofstitches

Delay time untiloption output turns on (02) Option output on time (03)

Delay time untiloption output turns on (04)

Option

Numberofstitches

(NOTE 30) Setting Is enabled when Function No. 70 Is

(NOTE

31)

Setting is enabled when Function No. 70 is

(NOTE

<Stltch

The

32)

Setting is enabled when Function No. 70 is

(NOTE

33)

(NOTE

Setting is

34)

The

number

enabled

stitch numbercontrol outputsignal

control

variable input signal should be

output

when

Function No. 70 is

signal>

connectedtoconnector

canbesetinaccordance

output

set

to "2".

set

to "4".

set

to "5".

set

to "2"or"5".

CN6.

for option output

on time

(05)

for option

for option output

The

output

Setting

output

with

the

signal is

details

(01)

(06)

(07)

variable input signal.

senttoconnector

CN11.

CN6

CN11

Motor

Needle

up signal

Variable Input signal

Output

signal

+5V

Extemal output; signal is

ov

No.113

open

collector output within maximum 10 mA

No.114

2262M

2263M

NOTE:

71

IfFunction No. 112 and No. 113 are

set

to "0",output is synchronized withthe variable input signal.

T-8400A,

8700A

^RJNCTONSETTJNGS^

Function

No.

115

(NOTE 35)

116

(NOTE 36)

117

118

(NOTE 37)

No.

115-118

Initial

(1.0

(2.5

(1.1

10

25

11

value

ms)

Setting

1-49

0.1-4.9

1-49

(0.1-4.9

1-49

(0.1-4.9

0-3

range

(ms)

ms)

Setting

On time when solenoid-type presser

Presser

foot

lifting

—

No.32

(fullyON)

details

lifter

solenoid is chopping

No.115!

5ms

On time when pneumatic-type presser liftersolenoid is chopping

Presser

foot

—

lifting

No.32

(fullyON)

No.llSl

5ms

On time when quick reverse solenoid is chopping

Quick

reverse

solenoid

—

85ms

Sewing pattern setting when

E-F-E-F

0:

1:E-F-E-F-G

2:

E-F-G-H-H-G-F-E

3:

E-F-G-H-l-H-G-F-E

(Name label attaching)

(Pocket sewing 1)

1 2

(fully

ON)

name

label key is on

m

(Pocket sewing 2)

m

•!

'No.117|

5ms

1

'

2264M

2265M

2266M

e\

(NOTE 35) Setting is enabled when Function No. 37 is

(NOTE 36) Setting is enabled when Function No. 37 is

(NOTE 37) When

set

When

set

When

set

numberIis

to "1", stitch

to "2", stitch

to "3", stitch

set

for

Function

number

No.

G is

25.

set

for function No. 23.

set

for function No.23and

set

for function No.

set

to "0".

to "1".

E G

23,

stitch

number

H is

set

for

h\ /h

Function

No.

24.

No.24and

2267M

stitch

T-8400A,

8700A

72

^UNCTJONSErnNGS^

Function

(NOTE

No. 119 120

121

122

123

124*

125

126

127

128

129

130

131

No.

38)

119-131

Initial

3000

1000

(degrees)

1

(seconds)

Setting is

value

3

5

(rpm)

45

0

10

0

14

enabled

Setting

200-5000

(rpm)

200-5000

(rpm)

30-90

(degrees)

0-1

0-120

(seconds)

0-3

-2-2

when

*... Settings indicated with" *"

range

-

fDo

[Do

not

Speed

Servo lock release angle (Do not

Material

0:

Detects

1:

Detects

Servo

0:

None

1;

When

2:

When

Servo 0: No

-

1-120:

[Do

not

Flicker reduction function (when flickering occurs from fluorescent light)

0:

None

1:

Medium

2:

Low

3: High flicker reduction

4:

fDo

Motor

-

fDo

not

Function No. 69 is

are

enabled when

change

this

when medium

when

low

edge

sensor

material

lock

operation

stopped

presser

lock timer

timer

Timer

change

flicker

not

acceleration

deceleration

change

set

setting

operation

operates

this

flicker

reduction

use

this

to "2".

the

power is turned off

setting.]

speed

switch is on

logic selection

absent

present

foot

lifting

(1-120

setting.]

reduction

setting,

gain

fDo

gain

fDo

setting.]

Setting

switch is on

change

signalison

seconds)

otherwise

not

change

not

change

and

details

this setting.)

the

motor

will

this

setting.]

this

setting.]

then back on.

overheat.]

Function

No.132-136

The following function

No. 132 133 134 135

136

Cumulative Cumulative Cumulative

ROM

Maximum

numbers

version

sewing

show

maintenance information.

powerontime operating

time

greased-up

(x.xxx)

speed

(Actual (Actual

operating

setting

Descriptionofdisplays

time=Displayed

time

(time=display

history

(rpm)

timex10) time

xxxx x

xxx x 1

10)

hour)

73

T-8400A,

8700A

9-6.

Clearing

saved

data

^^unctionset™^^

(Initialization)

<Typesofdata

When

saved

'

All

data

<lnitializing

Initializing all

1. While

2.

3. After this,

Initializing

1. While pressing the

2.

3. After this,

pressing

The

main display will

Press

the

Initialization

the

normal display.

The

main display

Press

the

The

speed

green.

the

normal display.

that

data is cleared, the following data

that has been

the

data>

data

the

ENTER key.

will

the

operation panel

only

speed

ENTER key.

data

the

operation panel

are

cleared>

set

using the operation panel (includingfunction setting data)

RESET

be carried out

MAX

will

will be initialized to

key on

changetoorange

and

data

key on

the

changetoorange

and

are

returned to factory default settings.

the

operation

and

the

"iniT

the

treadle

operation panel, tum on

and

the

speed

the

treadle

panel,

"iniT

ALL"

willbedisplayed.

ALL"

display

canbeoperated.

"iniTrPM"

canbeoperated.

willbedisplayed.

data

from

turnonthe

will

change

the

head

power

switch.

to green.

When an operation is carried out,

power switch.

detector

When an operation is carried out,

unit

and

the

"iniT rPM" display will

the

display will return to

the

display

will

change

retum to

to

Initializing

1. While pressing the FUNC key on the operation panel, tum on

The

2.

Press

Initialization of the function setting

3. After this, the operation panel and the treadle can be operated. When an operation is carried out, the display

the

<Clearing

only

the

main display

the

ENTER key.

normal display.

data

automatically>

function

will

setting

changetoorange

data

the

and

"iniTFUnC" will be displayed.

will

be carried out

and

the

power switch.

"iniTFUnC" display

will

changetogreen.

will

retum to

When the power is turned on for the first time, the treadle and the operation panel cannot be operated for a period of

approximately4seconds.

After approximately 4 seconds, the main display

the

sewing

Inaddition, this display

•

When

machine's

the

control

speed

will

box

also

has

settings

appear

been

have

inthe

replaced

• When a sewing machine with different

NOTE:

When the power switch is tumed on, any of the sewing machine'ssewing

the

head

detector

When initialization is complete,

unit

are

reset

automatically.

the

main display

Afterthis, the operation panel and the treadle can be operated. When an operation is carried out, the display

the

normal display.

will

been

initialized.

following

speed

specifications to

change to green and "initrPM"

cases

approximately 4

the

control box is connected

seconds

speeds

will

changetogreen

and

"initrPM"

will

be displayed. "iniTrPM"

after the power

has

been

means

turned on.

that

that are differentfrom the setting data in

will

be displayed.

will

return to

T-8400A,

8700A

74

10.

CONTROL

SYSTEM

(T-8421A.

8422A.

8722A)

10. CONTROL SYSTEM (T-8421A, 8422A, 8722A)

H

0

1

3110M

Turn on

A.

1. When

2.

B.

the

power

switch (1).

When

the

treadleIsdepressed

the

treadle

treadle unit (3) to

The

DD motor (5) that is directly linked to

depression

When

the

treadleisreturnedtothe

the

amount

amount,

(2) is

depressed,

control box (4).

from

the

control box (4), causing

and

this

makes

a voltage corresponding to

the

sewing machine receives a voltage that corresponds to the treadle

the

DD motor (5) to

the

sewing

neutral

machine

position

operate.

the

amount

operateatthe

of treadle depression is transmitted by

speed

representedbythe

treadle

the

1. When the treadle (2) is returned to the neutral position (when the operator's foot is removed from the treadle), a signal

Indicating that

electrical

2.

The

encoder brake is applied in (6) that is

0.

When

the

1.

When

the

(3) to

the

thread

trimmer]

2.

The

encoder

the

electrical

the

pulley

For models with thread trimmer,

machine

the

treadle is at the neutral position is transmitted by the treadle unit (3) to the control box (4),

brakeisthen

circuit board that is installed to

attachedtothe

treadleisdepressed

treadle

control box (4),

circuit board

brakeisappliedinordertostop

(6)

stopsatthe

applied to slow

ordertostop

(2) is

depressed

thatisattachedtothe

needle

the sewing machineatthe

DD motor (5).

backward

backward, a signal indicating

and

the

DD motor (5) slows down to the thread trimming

that

is installed to

the

up

stop

the

DD motor (5).

the

DD

motor

thread

position.

DD motor (5)

the

DD motor (5)

the

(5).

trimming

sends

a signal to

stopping position

thread

trimmer

sends

sewing

machineatthe

operationiscarried

and

the

(needle

operation

speed

control box (4)sothat

up or needle down)

is transmitted by

(inching

speed).

the

electrical

setbythe

the

treadle

[For models with

a signal to the control box (4)sothat

needle

out

up

stopping

immediately

position

before

the

set

sewing

the

pulley

unit

by

75

T-8400A,

8700A

11.

CONTROL

BOX

AND

MOTOR

(T-8421A.

8422A.

8722A)

11.

11-1.

A

CONTROL

(T-8421A,

Removing

Wait at before opening the face plate of the control box. Touching

severe

least

injury.

and

5 minutes after turning off

BOX

8422A,

Installing

AND

MOTOR

8722A)

the

control

A

DANGER

the

power switch and disconnecting the power cord from the wall outlet

1.

2321M

box

areas

where

high voltages

Remove

connectors (2) to (7) from * Be careful not to break the pawls of connectors (5), (6)

and

(7).

the

repeat

cable

are

present

tie (1),

and

the

sewing machine.

then

can

result in

disconnect

the

rVlJ

?

3123M

2323M

2. Disconnect

connector

3.

Disconnect

4.

Loosen

5.

Remove

6. Pivot

removeitfrom

the

power supply

(9).

the

ground wire (10).

nuts

(11)

bolt (13)

control box

the

connector

and

(12) (without removing them).

and

nut (14).

around

table.

the

bolt (15)

(8)

and

the

motor

pull it out to

2324M

T-8400A,

Install by following

8700A

the

removal

procedureinreverse.

76

^^ONTgOUBOXANDMOTOR^^^

11-2.

<Control

•

Check

Some

Model

Control

box>

the

specifications

— MD-741A:

MD-751A:

phase,

4

box

and

motor

voltage

and

type

for

are

identical for both single- and three-phase,

the

control box.

rating

Single-phase

Three-phase

plate

(appearsonname

plate)

Motors withanalphabetical symbol of "A"or after

for twin

The

sewing

needle

sewing

MD-7410/7510

machines.

cannot

be

used

with

twin

needle

are

brother

MD-751A

(MD741A)

144-52

CONTROL

NO.B3DAA1106^

Serial

No.

44-52

BOX

PHASE OUT PUT VOLTS

HERTZ

BROTHER

INDUSTRIES.

Power

Treadle

Operation

Sewing

1

or

550

220-240-

50/60

Destination

supply

machine

3 •

W

LTD.

voltage

unit

panel

Phase

Voltage

Serial

No.

Japan

1

Asia/Middle

2

USA/Mexico

3 4

Canada

Oceania

5

7

Turkey/

China

9

L

Europe/Greece

100V

1

110V

2

200V

3

220-240V

5

380-415V

8

4 1 forward 1

2

6

4

External

T-8421A.

1

North Africa

foHA/ard2backward

East

(C-TICK)

(CE)

backward

8422A,

8722A

step

3111M

type

77

T-8400A,

8700A

<Motor>

No.

brother

M-741HT

A04G1111

Serial

J^rCOJ2gO^OXANDMOTORjM421A^8^

No.

3117M

3118M

T-8400A,

8700A

78

11.

CONTROL

BOX AND

MOTOR

(T-8421A.

8422A,

8722A)

11-3.

A

<Name

(23)

(22)

(21)

(20)

Control

circuit

board

A

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.

and

functionofeach

) (2)(:

se

o

CN11

^li=3

00

o o

CN5

LD2

N-

part>

CN7

(6) (7)

CN8

DSW

DDDD

CN4

LD1

• •

F2 5A

• •

o

(11)

(12)

(13)

Connectors

(2)

(14) (15) (16) (18) (19)

(5) (6)

(10) (1)

(20) (13)

(3)

(21)

(22)

(9)

(23)

(19)

Head

detector

Option

connector

Solenoid-type

Sewing

Synchronizer

Operation

Relay Coupler

Control

Treadle

Standing

Puller

Option

Option Cooling

Thermistor

machine

connector

power

connector

operation

connector

fan

unit

presser

connector

panel

supply

power

connector

A

lifter

connector

1

2

3

supply

(18)

connector

(17)

Connect

Connecttotreadle

Connecttoplug

to sewing

to power supply circuit board connectors.

to

transformer

(sold

Connecttosolenoid

Connecttosewing

For

input/output

Connect

Only

used

to

stitch

for

signals

three-phase

Connecttoshorted

high-voltage

specifications.

(16) (15) (14)

machine

connectors.

unit

connector.

separately)

for

pullerorother

speed

actuator.

usedbyexternal

counter

actuator.

connector

connectors.

for

high-voltage

when

not

standing

device.

devices

specifications.

using

2328M

operation

three-phase

79

T-8400A,

8700A

J^ONTRO^OXANDMOTORj^421A^84^

Fuses

Terminal

DIP

LED

(21)

1

2 IN

3

4

5

6

7

8

9

10

11

(*)

Open

board

switch

indicators

Connector

+5V

SPSP STOP

ND

NU

ENG

STBY

SOV

ENC-A

ENC-B

collectoroutput

CN6

(8)

(11)

(12)

(17)

(4)

(7)

Solenoid

Illumination

Terminal

DSW

Red

Green

LED

Signal

DC

+5V

Variable

Speed

power

supply

lamp

board

name

signal

command

power

input

fuse

supply

(5A)

fuse

(5A)

Operation prevention input Llevel;

Needle

Needle Machine

down

signal output

C*)

up signal output (*) L level:

shaft

sync

signal (*)

Operation signal output (*) H level:

OV(GND)

A

phase

signal

output (*)

B

phase

signal

output (*)

For preventing overcurrent

For

Indicates

For

stitch

[Not

usedbythe

L level:

illumination

function

counting

Operation

Needle

lamp

selection

power

supply

that

the

power

T-8421A. 8422A, 8722A1

prevented

down

stop

Needleupstop

45

pulses/stitch

Operationinprogress

EncoderAphase

EncoderBphase

(180

(180 pulses/stitch)

(6 V)

circuit

board

is on.

Remarks

position

pulses/stitch)

problems.

(22)

Connector

1

+5V

2 UNTH_LED 3 UNTH_SW

4

SOV

5

INI

6

IN2

Connector

(3)

+5V

1

LED1

2

LED2

3

4

LEFT_UP_SW

5 RIGHT_UP_SW Option

RESET_SW

6

SOV

7

CN9

CN11

Signal

name

DC

+5V

Stitch

OV

counter

(GND)

LED signal

switch input signal

Variable input signal 1

Variable input signal 2

Signal

name

DC

+5V

Option

signal

output

Option

signal

output

Option

signal

input 1

signal

input 2

Option

signal

input 3

OV(GND)

Remarks

Stitch

output

Stitch

counter

warning LED

actuator

Remarks

1

2

Sewing Sewing

Sewing

speed speed

speed

actuator actuator

actuator

(high

speed)

(medium

(low

speed)

T-8400A,

8700A

80

11^C0NTR0^0XANDM0TOR^^8421A^^^

11-4.

A A

<Motor>

Checking

Turn off the power switch

The

machine may operate if

the

motor

and

power

A

supply

CAUTION

disconnect the power cord from the wall outlet before carrying out

the

treadle is

depressed

by mistake, which could result in injury.

these

operations.

Ifthe power switch needs to be left on when carrying out some adjustment, be extremely careful to observe all

safety

precautions.

3112M

1. Disconnect

box.

2. Measure

the

motor

the

resistance of

connector4P(1) from

the

motor

connector

the

(1) using

control

an ohmmeter in the x 1 range.

If

the

is

normal.

Between

Between Between

valueisas

2-3

3-4 4-2

showninthe

Approx.

table

1.6Q

below,

the

connector

<Power

switch>

<100Vtype>

<200 V type>

o

-o

Ground

-O

-o

1883M

1. Disconnect

control

2. Turn on

o

wire

O-

o

o-

1884M

3. Measure the voltage at

using the AC voltage

that

specified

100Vtype

200Vtype

[A]

[B]For

the

power supply connector6P(2) from

box.

the

power

switch.

range

the voltage is within

voltage

Measure

For

5-6

rating.

(100-120

the

AC voltage

(200-240

three-phase

Measure

single-phase

Measure

the

and

6-4.

theACvoltage

V)

AC voltage

the

power supply connector (2)

of a multimeter,

the

allowable

between

range

terminals

and

2-3.

check

for

4-6.

the

4-5,

81

T-8400A,

8700A

^^CONTgOLBOXANDMOTORgj^^

11-5.

A

<Machine

Sewing

r-g

m

Checking

the

solenoids

A

DANGER

Waitatleast 5 minutes after turning off the power switch

before

opening

head>

machine

the

connector

face

14P

plateofthe

Control

control box. Touching

box

2330M

DB

[u

1

Thread

trimmer

3

10

4

11

5

12

6

13

7

14

==!—

-W

oN) 1

1

Thread

1

I

Quick

]

Actuator

Safety

reverse

switch

solenoid

wiper solenoid

soienoid

switch

1886M

and

disconnecting

areas

where

high

Disconnect

the

control

treasure

(1) using an

If

the

connectorisnormal.

Between

Between Between

Between

the

sewing

circuit

the

resistanceofthe

ohmmeterinthe

values

are

3-10

4-11

5-12 6-13

7-14

the

power cord from the wall outlet

voltages

board.

machine

are

present

connector

sewing

machine

x 1 range.

as

Thread

7.6

Q

Thread Quick When

When

shown

in

the

trimming solenoid: Approx.

wiper solenoid: Approx. 5.7 Q

reverse

solenoid: Approx. 4.8 Q

actuator is pressed: OQ

actuatorisreleased:

machine

head

ON):OQ

When

machine

head

(switch OFF): wQ

can

result in

14P

(1) from

connector

table

below,

ooQ

is upright (switch

is

tilted

back

the

<Solenoid-type

Solenoid-type

Q]

E] [1}

3 6

E}

presser

lifter

connector

-W—I

connector>

6P

Knee

switch

Presser

lifter

solenoid

2331M

T-8400A,

Disconnect

(2) from

Measure

connector

if

the

connector

Between

8700A

the

solenoid-type

the

control circuit board.

the

resistanceofthe

(2) usinganohmmeterinthe

values

is

3-6

4-5

are

normal.

as

shown

Presser

When

liftersolenoid: Approx. 9.6 Q

knee switch is pressed: 0 Q

knee

presser

solenoid-type

switchisreleased:

in

lifter

the

connector

x 1 range.

table

presser

below,

ocQ

6P

lifter

the

82

12.

TREADLE

UNIT

ASSEMBLY

{T-8421A,

8422A,

8722A

12.

12-1,

TREADLE

(T-8421A,

Types

UNIT

8422A,

ASSEMBLY

8722A)

• The two types of treadle unit that are available are the type that controls the automatic presser foot

does

not.

•

You

can

switch

setting DIP switch 2;

Treadle

Does

<A>

Difference

spring

position

in

between the two types by

and

(C)

setting

unit

G

not

control

automatic

(A)

the

treadle stroke.

presser

changing the hooking

lifter

position

Treadle

Controls

of the spring (1) inside the treadle

unit

H

automatic

presser

lifter

and the type that

unit;

(B)

<B> DIP

switch

setting

<D>

Depression

force

<E>

Depression

signal

(NOTE 1) The

set

knee Furthermore. IfFunction No. 41 is

depressed

DIP

switch2;OFF

<When

depressing

the

treadle forward>

switch2:ON

<When

depressing

the

treadle

forward>

The presser foot lifter control signal is not output The automatic presser foot liftersignal is output at

when

the

treadleisbeing

depressed.

Carry out the setting in "Setting method for

depression

Set

and

<When

backward>

The

startofdepression

<

When

The

<

When

The

presser

to OFF, the

switch

strokes"onpage

85.

the neutral position, maximum forward position

maximum

depression

sewing

backward

depressed

machine

depressed

machine

position.

forward

force hardly

until full

forward

starts.

backward

starts.

and

changesatall from

depression.

>

(NOTE 1)

foot liftercontrol signal is output while the treadle is

presser

has

been

backward.

foot liftercontrol signal is not output when the treadle is

used

to raise the

set

presser

to "1",

standard

depressed

foot.

the

presser

the position before the treadle depression force

suddenly

Carry out

depression

Set

and

changes.

the

setting in "Setting method for

strokes"onpage

85.

the neutral position, maximum forward position

maximum

backward

position.

The first modulation position for

depression

<When

backward>

The

the

between

<When

backward>

An

point before the

changes,

after

foot liftercontrol signal is not output

forceisset

depressed

depression

the

depressed

automatic

and

the

depression

depressed

automatically.

fonA/ard

force

suddenly

startofdepression

forward

presser

lifter

depression

the

sewing

machine

force

suddenly

and

changes

and

full

and

signalisoutputatthe

force suddenly

starts

changes.

backward. However, if DIP switch 1 is

depressed

backward after the

when

standard

the

treadle

depressed

at a point

depression.

depressed

at the point

the treadle is

T-8400A,

8700A

12.

TREADLE

UNIT

ASSEMBLY

(T-8421A.

8422A.

8722A)

12-2.

Function

No.

Standard

Symbol (diagram

below)

-

82

83

84

85

-

81

80

-

SO

SI

S2

S3

S4

S5

S6

S7

S8

(NOTE 1) Setting Is (NOTE 2) Setting Is

setting

Specification

Operation

Spring position setting

Function

Neutral

Fonvard

lifter

Low

starting

Speed

Maximum

point

Maximum

depression

Back

lifter

Thread

point

Maximum back

point

enabled enabled

point

automatic

operating

speed

point

change

speed

point

automatic

operating

trimmer operating

when

DIP switch 1 Is

when

Function No. 12 is

values

presser

point

operation

starting

reaching

forward

presser

point

depression

Treadle

Does

presser

No forward/back

modulation

(Figure [a]onprevious

Length from SO

(mm)

point

set

toONand

setto"0".

unit

not

lifter

0

-

3

6

S5-1

14.5

-

5

8

G

control

Function

automatic

1st

page)

Force

No.13Is

step

Treadle

Controls Forward/back

modulation

unit

automatic

(Figure [b] on

(N)

-

- 2 (NOTE 1)

10

-

12

-

22

28

Length from SO (mm)

0

5

7

S5-1

14.5

2 (NOTE 2)

5

8

setto"1".

H

1st

page)

Force

lifter

step

(N)

-

10

25

-

32

14

35

43

• When

the

connecting rod installation position is on

treadle from the neutral position to

• For treadle unit-H, the point of

(R) in

the

backward

Speed

depression

the

change

force Is

the

inside,

the

fonvard position

andtothe

measurement

backward position.

valueisthe

(F) in the fonvard depression force is betweenSIand S2,

betweenS6and

S7.

amountofmovement

and

the point of change

of the

s—

Backward

depression

Neutral

T-8400A,

Forward

8700A

depression

1841M

84

12.

TREADLE

UNIT

ASSEMBLY

fr-8421A.

8422A.

8722A)

12-3.

A

When the specifications of the treadle unit

necessarytomake Use

1)

Setting

Wait at least 5 minutes after turning off

before opening the face plate of the control box. Touching

the

following procedure to

Signal

setting

method

new settings according to

for

standard

set

the

operating positions for

entry

depression

A

are

changed or if the treadle unit or control circuit board are replaced, it

the

CAUTION

the

power switch

procedure

described

the

2332M

and

depression

1.

Turn

2.

Set

3. While pressing the thread trimming key (2), tum on

power

"PdFF

(x.xxx indicates

strokes

disconnecting the power cord from the wall outlet

areas

where high voitages

below.

stroke.

off

the

power

DIP

switch

No.4toON.

switch (1). x.xxx"will

the

switch (1).

appearinthe

depression

are

present can resuit in

main display (3).

voltage.)

will

be

the

2)

Memorizing

85

the

maximum

forward

position

2333M

2334M

T-8400A,

With

the

position,

"Pdnn

8700A

treadle

press

x.xxx"

deoressed

the

thread

will

appearinthe

fonwardtothe

trimming key (2).

main display (3).

maximum

fonward

3)

Memorizing

the

neutral

position

J^gEADL£UNr^SSEMB^^^8421A^

With vour foot trimming key (2). "Pdrrx.xxx"will

2335M

released

from

appearInthe

the

treadle,

main display (3).

press

the

thread

4) Memorizing

5)

Completionofsetting

the

maximum

backward

(4)

position

2336M

With

the

treadle

backward position,

"Pd-

x.xxx"

will

1.

Press

the

ENTER key (4).

The

buzzer

will

off.

NOTE:

If youdonot

will

notbememorized.

depressed

press

the

appearInthe

sound

and

press

backward

thread

to

the

trimming key (2).

main display (3).

the

main display (3) will switch

the

ENTER

key

(4),

maximum

the

settings

2337M

t—itaii

2. Turn off

3.

Set

II

2338M

T-8400A,

8700A

DIP

the

switch

power

No.4toOFF.

switch (1).

86

J^3^STANDINGOPERATJO^^

13.

The

foot plug

13-1.

A

STANDING

(T-8421A, 8422A,

assembly

Installing

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

CDD (J04099-001) that is sold

the

OPERATION

foot

plug

A

8722A)

separately

DANGER

PEDAL

is required.

areas

where high voltages are present can result in

(CN3)

1. Connect the foot plug (1) to connector CN3 on the control circuit board.

2. Connect the standing pedal connector (2)to the foot plug (1). with

3. Secure the standing pedal cord (3)

a repeat cable tie (4).

r^

2339M

87

T-8400A,

8700A

J^TANDINGOPERATJONPEDAyT^^

13-2.

<At

Connectors

foot

plug>

r\

No.

1 2

3

4

5 6 7 8 9

Standing

9P

connector

DC+8V

High-speed

Thread SOV

Spare

Low-speed

Presser

Variable

Ground

trimmer

operation

switch

foot

switch

speed

pedal

switch

input

2340M

<At

pedal>

®©®(

(D©®

©®o^

<A> Two-step

pedal

®

©@

®®®

1867M

NOTE:

Connector

Manufacturer

MOLEX

<B> Variable

types

Connector

1292

speed

©©©

©®®

No.

P

pedal

Connector

1380TL

terminal

®®©-

mi

^ d ST

3^

(A 0) M M

•O

(D ? S

® 3" s

Q. 3

i

<D ^ W

ffl «=»•

3

iQ

<3

o

®®©-

T-8400A,

UII

M ^ -

3-

(0 < w

u, 0)

•a "g ?

fl) ^ ro ^

I I a f

8700A

CO

3

TJ

(5

u

1868M

88

14.

TROUBLESHOOTING

14.

Please

Ifthe

purchase.

A

14-1.

1

TROUBLESHOOTING

check the

following

Wait at least 5 minutes after turning offthe power switch and disconnecting the power cord from the

before opening the face plate of the

severe injury.

Turn off The machine may

When using a clutch motor, the motor

motor's inertia. Wait until

Sewing

Poor

thread

Upper

Lower

Loops

following

remediesdo not

the

power switch

Problem

tightening

thread

threadisnot

appearinseam.

points before callingfor repairs or service.

fix

the

problem,

turnoffthe powerswitchand consulta

A

control

box. Touching areas where high voltages are present can result in

A

and

disconnect the power cord before carrying

operateifthe

is not tight.

!•

tight.

the

treadle is

motor

Has

Is

small?

depressed

will

keep tuming even after the power is switched offasa result of the

stops

fully before starting work.

the

thread

been

If

the

threadisthreaded

the

upper

thread

Adjust

the

upper

the

thread

take-up

Lower

the

position of

the

thread

path

Use

a file with a fine grainorsandpaper

thread

path.

the

bobbin not tuming smoothly?

Pull

out

the

thread

tension,orreplace

the

thread

take-up

Adjust

the

thread

the

clearance

Adjust

the

clearance

the

Adjust

the

Adjust

plate.

feed dog

clearance

the

too

feed

DANGER

CAUTION

out

troubleshooting.

by mistake, which could result in injury.

Possible

threaded

tension or lower

thread tension or lower

spring operating

the

not

smooth

lower

threadtocheck

amount

take-up

between

clearance

high?

dog

the

between

height.

the

cause

incorrectly?

incorrectly,

stopper.

enough?

too

large?

amount.

rotary hook

rotary

between

thread

tension

thread

range

too

that

thereisno

the

bobbinorbobbin

and

the

rotary

hook

and

the

rotary

it correctly.

small?

to polish

the

hook

qualified

too

tension.

opener

and

needle

and

technician or the place of

weak?

smooth

slackness

case.

too

the

large?

opener.

plate

the

needle

the

in

too

wall

outlet

Page.

Instruction

manual

Instruction

manual

11

13

27

29

26

0574M

0573M 0977M

89

T-8400A,

8700A

14.

TROUBLESHOOTING

Problem

Possible

<8422A,

8722A>

• Is the thread being hooked onto the

Adjust

forward-back position of

cause

the

tip of the movable knife?

the

movable knife.

If using a sewing machine with medium-weight material

specifications,

type of material being

In

such

the underside, or replace

(Refer to the parts book for details

cases,

poor

replace

thread

tightening may occur depending on

sewn.

the

presser

the

foot with

one

feed dog witha grooved feed dog.

suchaspart codes.)

Slot

that

has

slots

Grooves

2944M

Page

36

the

on

Skipped

while

sewing

stitches

occur

Is the

needle

tip

bent?Isthe

If

the

needle

tip is

bentorbroken,

Is

the

needle

properly installed?

Ifit is incorrect, install

Is the machine properly

Ifit is incorrect,

Is the

presser

foot

threaded?

thread

pressure

Adjust the presser foot pressure.

Is the

needle

too thin? Is this causing needle deflection?

Is

the

Try using a

current

Is the

Adjust

function or

Is the

Adjust

Is

the

Replace

needle

presser

If using

thread

Adjust

the

needle

with a

too

thick

for

needle

needle.

foot too high?

the

height of

the

reduce

take-up

the

tension of

take-up

the

thread take-up amount.

the

presser

the

spring

amount

Is the rotary hook tip out of

Correct

hook.

Is

the

Adjust

Are the

Adjust

Is

the

rotary hook

Adjust

clearance

the

needle

the

clearance

correct?

the

shapeofthe

between

position of

height

needle

between

position of

and

needle

tip blunt?

replace

the

needle

correctly.

the

thread

correctly.

too

weak?

needle

thatisone

the

thread?

with a count that is

presser

foot minute

foot.

lifting

floating height.

too

weak?

the

thread take-up spring.

too

large?

shape?

rotary

hook

the

needle

and

the

rotary hook base.

needle

bar

liftamount correct?

rotary hook timing.

the

needle

the

rotary hook base.

and

the

needle.

rank thicker.

one

lower

than

function, stop using

tip, or

rotary

the

replace

needle

hook

tip

guardofthe

the

correct?

the

rotary

Instruction

manual

Instruction

manual

Instruction

manual

Instruction

manual

Instruction

manual

27

43

12

13

26

24

20

24

2945M

T-8400A,

8700A

90

14.

TROUBLESHOOTING

3

Skipped while

sewing

Uneven

Problem

seam

stitches

occur

2945M

• Is

the

sewing

speed

too

<T-8420A,

Check

8720A>

whether

the

diameter) that matches

frequency of your particular model

being

used.

Ifit is not correct,

* Depending on

the

8422A,

whether

may

standard

speed

the

stitches within

operating

smaller.

<T-8421A,

Check

swing machine model

Ifthey

are

not correct,

to "Maximum sewing

* Depending on

stitches may still within

the

standard

sewing

speed

• Is

the

• Is

•

the

Is

the

presser

Adjust

presser Adjust If using

function or

feed

Adjust

bobbin

If

replace

the

dog too low?

the

scratched?

the

bobbin is

it.

foot

pressure

presser

foot

too

height of

presser

reduce

feed

dog

damaged,

Possible

cause

^st?

correct motor pulley (with

the

maximum sewing

and

replace

the

still

occurIfthe

speed

the

motor

type

of material or

range.Insuch

pulley.

maximum

by selecting a motor pulley

8722A>

maximum

and

reduce

speed

the

occurifthe

control keys to

too

foot

pressure.

sewing

speediscorrect

specifications.

the

sewing

setting method".

type of material or thread, skipped

maximum sewing

speed

range.Insuch

reduce

weak?

high?

the

presser

foot.

foot minute lifting function,

the

floating height.

height.

smooth

it withanoiled

the

correct

speed

outer

and

sewing specifications is

thread,

sewing

cases,

speed

skipped

speed

reduce

thatisone

size

for

while referring

the

speed

the

cases,

sewing

stop

use

speed.

using

the

grindstone

Paqe

Instruction

manual

is

57

is

Instruction

manual

Instruction

manual

27

43

29

or

4

Material slippage

(For lower feed)

2948M

2950M

<T-8420A,

•

Is

the

• Is

the

8720A>

V-belt

tension

Adjustsothat

when

it is

pushed

presser

Adjust the

foot

presser

too

low?

thereis10-14

with a finger.

pressure

foot

too

pressure.

mm of deflection in

strong?

the

V-belt

Instruction

manual

Instruction

manual

91

T-8400A,

8700A

14.

TROUBLESHOOTING

Large (excess

Problem

degree

tension)

of puckering

Possible

Is

the

needle

too

wide?

Replace

Is the upper

Make

Is the lower

Make

with a

needle

that isasnarrowaspossible.

thread

tension too strong?

the

upper

thread

tensionasweakaspossible.

thread

tension

the

lower thread tensionasweakaspossible.

too

strong?

Are the thread take-up spring tensions too

Make

the

thread take-up spring tensionasweakaspossible.

Is the thread take-up spring operating

Move

the

Is the

Is

the

Is the

• Is the

presser

Adjust

the

thread

Adjust

the

needle

Replace

NOTES:

The

needle

without

(Referto

sewing

<T-8420A,

Check

whether

diameter)

stoppertoas

foot

pressure

presser

take-up

amount

thread

hole in

the

with a

feed

hole in

causing

the

parts

speed

too

8720A>

the

that

matches

high a positionaspossible.

too strong?

foot

pressure.

too

take-up

amount.

feed dog too large?

dog

with a

the

feed dog should beassmallaspossible

the

needle

book for details

to break.

fast?

correct

motor pulley (with

the

frequency of your particular model

being

used.

Ifit is

not

correct,

* Depending on

may

still

standard speed

replace

occurifthe

speed

the

type of material or thread, puckering

maximum sewing

range.Insuch

by selecting a motor pulley

cause

strong?

range

too

small?

smaller

suchaspart

hole.

maximum sewing

and

sewing specifications is

motor

pulley.

cases,

thatisone

large?

codes.)

the

speed

reduce

correct

speed

is within the

the

operating

size

smaller.

Page

Instruction

manual

Instruction

manual

Instruction

manual

12

11

Instruction

manual

13

outer

and

Instruction

manual

2949M

<8422A,

<T-8421A,

Check

swing

Ifthey

to "Maximum

* Depending on

8722A>

8422A,

whether

machine

are

not correct, reduce

8722A>

the

model

sewing

may stili occur if

standard

speed

control keys to

maximum sewing

and

specifications.

the

speed

setting method".

the

type of material or thread, puckering

the

maximum sewing

range. In

reduce

sewing

such

the

speed

cases,

sewing

is correct for

while referring

speed

is within the

use

the

speed.

the

sewing

• Ifusing a sewing machine with heavy-weight material specifications,

is a

presser

being

Useapresser

Useafeed

(Referto

foot with slots on

used?

the

foot without slots.

dog without grooves.

parts

book for details

Slot

underside or grooved feed dog

suchaspart

codes.)

Grooves

2944M

57

Instruction

manual

T-8400A,

8700A

92

Brother T-8420A, T-8421A, T-8422A, T-8720A, T-8722A Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual