Juki Moj 2500n series User manual

lYSi56'LWl

No.

01

r

Thank you for buying the JUKI MOJ/MOK-2500N

BEFORE OPERATION

1.

Do not hold the cloth plate cover when carrying the

machine.

2.

Resupply oil if the red color in the oil gauge is not seen

when the oil gauge

is

observed from the top or the side.

3.

Apply

a

few drops of oil to the needle bar guide

and

upper looper guide before operatingyour

new

rnach~ne

or

starting your machine for

the

first time

~n

a

ioog time.

Also, lubricate

the

oil holi:

sf

link

(A)

and

ttre

top

feed

presser bar. (Refer

?o

"2,

LUBRiCATiUN".i

4.

Never allow

the

sewing

machine

to

sun

in

the

reverse

directioi!.

The

hdndwhrei

shrjr;ld

rcirr.

clockwise

as

1

series sewing machine. TheMOJIMOK-2500N series

I

models have basically the &me mechanism

as

those of MOG-2500N series models except that the

top feed mechanism has been incorporated

in

MOJ/MOK-2500N series models. For this reason,

I

thl Instruction Manual mainly deals with

the

too

I

feed mechanism only.

he

customers are re-

quested to refer to separate instruction Manuals of

MOG-2500N series models for the common instruc-

tions omitted from

this

manual.

MOJ

1

(Example) For

MOK

-

25

16N

Top feed mechanism

I

CAUTIONS IN OPERATION

I

1.

Do not put your hand under or near the needle when

turning the power switch

ON

or while the machine

is

operating.

2.

Do notput your fingers intotheface plate cover while the

machine

is

operating.

3.

Be sure to turn the power switch

OFF

when removingthe

V

belt.

4

Dor~ngoperation, be careful not to allow your or any

other person's head or hands to come, or place anything

close to the pulley,

V

belt or motor. Any of these actions

may

develop dangerousconditions.

"

if

vour machine

is

provided with abeltcover, finger guard

CJT

any other protectors, never operate your machine with

any

of these removed.

F.

Do

not wlpe off the surface of the machine head using

racouer thinner.

.-

-

--

1

-

.-

--

.-.

..~

--.

...-.-.----.--.-".A

....

.-

1

.,;:).:~:..;::*

-:,.~

MOK-3500N

series

.

~-

~~

~.

-

.;j,-:.:-

l%.,

.

~..

~.

~~-~

~-

~

7,

.

h

;,

: :

i:~~:!?.

,,!.t:':;

,!li,kL,

.

,.-

.

:

-

,-'

,..

.

r:

.;j

,

.>

t.

..:

i,

6

:,i.:,.;.

f,(;l;<j

.

:-

j,i.

I

\

:

i

/:

i

+,

,

!.

fi<:1::

:9!!.3;

,(;,>kc,

of

Max.

6000

s.p.m.

..-

.

.,

.

:::.

if:.

\

'(11

if;

,

:cr>

~

~-

~ ~

~

..

.

I

:

i

:

>r

.i,,:.~:-,,:i

1:

:

<

.i:

...

.-

i

.i

i:

.

'

:

,.

/

,

:.

*..;

~

.

~.

,

:,

,

~~-~

-~

i

1

!;[

{,<t:.,:

!.

:>-,.:

,'\,C

~~

<

----

,

-

'

Y;:~I

,<,2i

x?:c,kL,

L,+

!<j?

:

;

,,

,!,

,!

4

-,

8-,;:~:,,

-

.--

~

.

~

5

-

6.5

mm

-

----

-

--

-

j

1

~lr~.~~?~~,li::al

\:rok\>

<)t

::;~j

ic,

J

..its

3

;I!;,;

-

~-~

~

-

Max.

6

mm

1

Lift

oi

;?ri.\cr

f~o!

Y

i;rr,

8

mm

I

*

i

Zleans the

ratio

,it

!hi:

rndi!l

red

3oi.r

i!:~:giru.lii?:~l

.trok.r

t,?

the

!op

feed dog longitudinal stroke. This ratio

is

factory-

adjusted

to

1

:l

.I

-.

1

::.8

for

the

blOJ-:(

136,

a~id

i

:0.7

-

!

:

1.8

for

the

MOJ-2516N.

("2)

The top

feed

dog

has

3

long

end

for

betre:

<titchine

perforn:ance.

When the maximum longitudinal stroke

of

8.5

mmof the

top feed dug

is

nece.;sar)~.

out the end

ot

the

top

feed

dog

bl

3

mm

by

a maximum.

12.

LUBRICATION

~p~

-~

-

Before operating a new machine or a machine which has

not been used for an extended period of time, apply a

few drops of lubricating oil to oil hole of link

(A)

0

(lubricate the bushing from the front knife driving arm

shaft) and top feed presser bar

@

.

MATPARTS

.

3.

PRESSER LIFTING CHAIN

Install presser lifting chain by attaching S-shaped

hook

@

to the hole in the end of lifting lever

@

(small).

4.

PRESSER FOOT

1. To remove the presser foot, turn the pulley anti1 the needle bar reaches its highest position. Fully depress the lifting pedal to

raise presser foot

0

and top feed dog

@

.

2. Lower lifting lever

@

in the direction of the arrow, and open the presser foot to remove it.

3.

To install the presser foot, reverse the above procedure, close the presser foot,and raise the lifting lever.

(Important) Be sure that presser foot arm

@

has been properly set onforked portion

0

of presser bar

Q

beforestartingthe

machine.

5.

CHANGING THE TOP FEED AMOUNT (HORIZONTAL STROKE)

The topfeed amount varies when the bottom feed amount (stitch

length) is changed by the pushbutton switch.

(Refer to the

MOG-2500N

Instruction Book for how to adjust

the stitch length.)

When the maximum top differential feed ratio(l:2.8(2514N),

1:

18

(2516N)

or more) is used at the maximum stitch length cut

the rear end of the top feed dog. This is necessary because the

rear end of the top feed dogmay come into contact with therear

end of the slot in the presser foot when the top feed dog is in its

backmost position.

(Note) In the

MOJ-2500N

model, when the stitch length and

the top differential feed ratio are changed, be sure that a

clearance of

1

mm or more

is

produced between the slot

in presser foot and the end of top feed dog

@

when the topfeed dog

is

inthefront end position. Ifthe

clearance

is

less

than

1

mm, cut the end of the topfeed

dog by

3

mm at amaximum.

MATPARTS

6.

ADJUSTING THE VERTICAL STROKE OF THE TOP FEED

DOG

I

--

-

--

-

7

To change the vertical stroke of the top feed dog, move the side

cover back, loosen setscrew

@

of topfeed adjustor

@

attached

to knife driving arm shaft

0

.

and move adjustor

@

up to

increase the vertical stroke or down to decrease it. Be sure to

securely tighten setscrews

@

.

Adjust the position of felt

@

so that it is in slight contact with

link (A)

@

.

At this time, be careful not to allow felt

0

to

come into contact with other adjacent parts.

*

For MOJ-2500N models

Adjust the vertical stroke of the top feed dog within the range

in

which red marker line

@

engraved on knife drivingarm shaft

0

stays between two red marker lines

@

on top feed adjustor

@

.

When red marker line

@

is set to lower red marker line

@

,

the

maximum vertical stroke of

6.5

mm is provided.

When red marker Line

@

is set to upper red marker line

@

,

the

minimum vertical stroke of

4.5

mm is given.

(Caution) Never set red marker line

0

beyond the lower red

marker line engraved on the top feed adjust (Be sure

that the set vertical stroke does not exceed

6.5

mm).

*

For MOK-25001Umodels

Adjust the vertical stroke of the top feed dog within the range

in

which red marker line

0

engraved on knife drivingarmshaft

0

stays between two white marker lines

@

engraved on top feed

adjustor

@

.

When red marker line

0

is set to lower white marker line

@

,

the maximum vertical stroke of

6.5

mm is given, and when it is

set to upper white marker line

@

,

the minimum vertical stroke

of

5

mm is given.

1

7.

ADJUSTING THE TOP DIFFERENTIAL FEED RATIO

I

1

/e/

Top feed dog

Presser

foot

The top feed amount can be altered without changing the bottom

feed amount, by top-feed adjusting lever

.

1.

Turn lock nut

@

in the direction of arrow. Move top-feed

adjusting lever

0

to work the top differential feed mecha-

nism.

2.

When the lever is set to

"S",

the top feed amount will be

reduced. The top feed amount will increase as the adjusting

lever is set to a larger number on the scale.

3.

After adjustment, turn lock nut

@

in the opposite direction

from the arrow to lock top-feed adjusting lever

0

.

*

For MOJ-2500Nmodels

The Standard MOJ-2500N machine head is usuallv factorv-

adjusted to a

1

:2.8 (MOJ-2514N),

1:

1.8

(MOJ-2516~)(main

feed dog: top feed dog) top differential feed ratio. If other top

differential

feed

ratios are necessary, adjust as follows:

1.

Cut the front end of the top feed dog by

3

mm at a maximum

so a clearance of

1

mm or more is produced between the front

end of the top feed dog and the front end

of

the slot in the

presser foot when the top feed dog is in the most advanced

position.

2.

Then, loosen

@

of stopper

0

,and move the stopper down

to adjust clearance

0

as tabulated below:

Clearance

0

Max. top differential feed ratios

MOJ-2514N MOJ-2516N

1

:2.1 1:1.3

1

:2.8

1

:

1.8

Max. 1

:4.8

3.

If

a

top differential feed ratio other than those listed above is

required, perform the following adjustment:

Remove the cover from the adjusting hole in the rear of the

machine frame, loosen locknut

@

to release main feed arm

Q

,

and move the main feed arm pin down. When the pin

is set at the lowest point, the maximum top differential feed

ratio of

1

:6

will be provided. After adjustment, securely

tighten nut

0

.

MATPARTS

8.

ADJUSTING THE HEIGHT OF THE TOP FEED DOG

To adjust the height of the top feed dog, loosen setscrew

@

to

release the top feed dog. Then, move top feed dog

0

up or

down to obtain the desired height. The standard height of the

top feed dog is such that it juts 1.8 mm from the throat plate

surface when it is in the lowest position of its stroke. When

sewing light-weight materials, adjust the height of the top feed

dog sothat it comes in slight contact with the bottom feed dog.

9.

PROHIBITED ADJUSTMENT

Never adjust supporting arm stopper screw

0

.

If the screw should be tampered with, the normal motion of

the top feed dog will be disturbed and extremely hlgh load

will be applied to other parts, resulting in shortened

life

of

1

10,

ADJUSTING THE PSESSURE OF THE TOP FEED DOG

I

.

~

--.

~

...

~

.~

-7

Loosen nut

0

and

turn adjusting screiv

@

In to Increase the

/

pressure of rhe top feed dog and the feeding power accordingly.The

following table shows standard height

0

of adjusting screw

@

.

'---

.~

(Cautions)

1.

Ifthe top feed dogjumps with a louder noise during operation, turnthe adjustingscrew in untilthe noise

is

reduced.

2.

Do notoperate thetopfeed dogwith

its

loud noise uncorrectedfor alongtime,or other relatedpartsmay beadverselyaffected.

3.

Do not give the top feed dog more pressurethan necessary,or the sewing machine will be subjectedtoextra loadwhich exerts

bad influence on the durability of the machine.

4.

It

should be noted that Dimensions

0

shown intheabove table (heightstoapply slightly higher pressure of the top feed dog)

are applicable to the longitudinal strokes of the top feed dog and the sewing speeds specified inthe above table. Accordingly,

Dimension

0

may be increasedtoapply lower pressure of the topfeed dog if the machine

is

operated

at

a

lower sewingspeed

or with

a

smaller longitudinal stroke of the topfeed dog than those specified inthe table.

1

I

1.

CONVERSION BETWEEN MOJ-2500N AND MOK-2500N

For

MO?

Top

feed

dog

When converting the MOJ-?SOON to the MOK-?SOON and vice versa, replace the presser-

foot (asm) and the top feed dog. then adjust the top feed arm stopper, and the vertical

stroke arid pressure of the top feed dog according to the following table:

I

MOJ-?SOON/UOK-?~OON/ Remarks

I

Top feed arm stopper

~

Refer to

"7.

ADJUSTING THE TOP

DIFFERENTIAL FEED RATIO".

1

Refer to "6. ADJUSTING THE

feed

1

4.5

-

6.5

1

5

-

6.5

stroke (mm)

I

VERTICAL STROKE OFTHE TOP

,

FEED DOG".

Height of top feed dog 15.5

-

16.5

-

Refer to

"10.

ADJUSTING THE

adjust screw (mm)

1

16,5

1

PRESSURE OFTHE TOY FEED

I

DOG".

Please

do

not hes!tale lo conracr

obr

dlstr~bilto:~or agents n vour area for further ~nforrnat~ons

whr

necessary

%Appear arld s~ecifcat~or>lsted in :hs instruc!ion rnariual

are

subjected to change wthout

not~ce

JUKl CORPORA1-ION

HEAD

OFFICE

BUSINESS

OFFICE

CABLE

JUKl

TOKYO

2-1 8-CHOME

KOKURYO

CHO

23

3

KABUKI

CHO

1

CHOME

TELEX

322967

232

2301

ChOFU

CITY

TOKYO

JAPAN

SHINJUKU

KU

TOKYO

160

JAPAN

PHONE

03(205)1188 1189 1190

1990

7

Printed

In

JaDafl

MATPARTS

Congratulations on your purchase of

JUKI

MOG-2500NSeries machines.

Please read

this

Instruction Manual carefully

before using these units inorder to get the most

out of them and to enjoy using them for

a

long

time.

For the first one month or

so,

operate the

machine at about

80%

speed

of

its

max.

sewing

speed.

1

I

BEFORE OPERATION

.~.--

7

,

i~

-.

.

--

,

,,'..

.'

cloth

plate

cever

.

-i

,,,;7

.

.-

,

!

,

,,'T-

b-.ir

,.ti~i..i

-

--

-

(Vtewed

from top)

(Viewed

from

s~de)

-

.rw~Y-IWT

T

2.

If the

red

color is not seen when you look down or

i

1.

Do not hold the cloth plate cover when carrying the sideward at the oil gauge, supply oil in accordancewith

1

machine.

-

--

"6.

Lubrication".

-

--

3.

Apply two or three drops of oil to the needle bar guide and upper

~

looper guide when operating the machine for the first time after setup

or after

a

longperiod of disuse.

I

-

---

4.

The correct machine running direction

is such that the handwheel turns clock-

wise as viewed from the handwheel's

side. Never run the machine in the

reversedirection.

I

CAUTIONS

IN

OPERATION

Fdce

olate

cover

,

.

:-,

-

.I:,

i:~i

pui

it.:i~

hand intothe

3.

Be sure to turn off the power

j

.-...,

SF,i

p!?te

cx~?;~~~i

while the switch before you remove the

V

~::aq!-.;:.::.

,s

r;,!;!?;.\q

.

belt.

-~-

~-

.,

*

.

:,

3

.

.;::-

1f

your machine

is

providedwith

a

belt wver,finger guard

and

eye

guard,

never

operate your mach~ne

with

any of

:hew

removed.

.lo

7..~r

riff

:he

of

?he

machi:??

%ad

using

MATPARTS

1.

INSTALLING

THE

FRAME SUPPORT PLATE

1

*

Semi-sunkentype

+

Fully-sunkentype

I

I Attach blower case

@

,

rubber cushion

@

,

spacer

'

Q

,

case presser plate

@

,

and case sponge

@

to

frame support plate

0

.

Table

1

2.

Install frame support plate

0

directly to the table.

3.

Install upper waste chute

@

to the left on the table,

and then attach lower waste chute

@

to the upper

waste chute.

The installation of the chutes can be adjusted within

a length of

56

mrn.

-

--

-

1. Attach frame supPo; ;late joint

Q

,

blower case

,

rubber cushion

0

,

case presser plate

Q

,

andcase

sponge

@

to frame support plate

0

.

Cloth

plate

\.

Table

I

2.

Install frame support plate so that the cloth plate

is

5

mm

higher than the surface of the machine table.

/

3.

Attach waste chute

@

to frame support plate

0

.

-

--

-

.

-

--

-

.-

MATPARTS

2.

MOTOR PULLEY AND V BELT

Sewing

5peed Motor pulley

V

belt (~nch)

1

Motor pulley

.

"

'

"

'

Outer

*la

<--~Ty-\unken Outer

*la

/

(mm)

I

type

I

type

(mm)

I

6,000 125

38

34

1105

1

36

3

I

1.

Use a

400W

(1

/2

W)

clutch

motor.

2.

Use an

M

type

V

belt.

3

The table

on

the

left

shows

the sewing speeds obtaineci

by the use of motor

pulleys

with different diameters and

V

belts with different lengths

4.

Note that the effective

dia-

meter of the machine head

pulley has been changed to

56

mm,

which is different

from

that

for

the

M0-2000W

4.

INSTALLING THE PEDALS

series.

3.

ATTACHING THE BELT

COVER

.

-

I

i

1

I

Lppp-

--.l

.

-~

--~,

I. Install starting pedal

0

on the left and presser lifter pedal

8

on

Install belt cover

0

to the machine head. the right as seen from the operator.

2.

Use an S-shaped hook

@

to connect the chain

@

of the presser

lifter pedal to presser lifting lever

0

.

5.

SETTING UP THE THREAD STAND

For

MOG-2504N

MOG-2514N

I

For

MOG-2516N

Assemble the thread stand

components as illustrated and

set it up on the machine table.

MATPARTS

1

6.

LUBRICATION

I

--

1

1.

'

Remove oil cap

0

.

2. Pour JUKl New Defrix Oil No.2 into the oil reservoir.

3.

Supply oil until the red color (oil level) almost reaches the up-

per red marker line when oil gauge

@

is

observed from the side.

(Caution)

Be careful not

to

exceed the upper red marker line, or else trou-

bles due to excessive lubrication may result.

4.

Remove oil drain cap

@

when draining the oil reservoir.

-1

*

Checking and cleaning the

oil pan

Once or twice a year, remove the

oil pan and clean section

0

of the

clothfilter.

At the same time, replace the oil

1

0

I

in the oil pan, if it has become dirty.

*

Installing the needle cooler

1--

Throat plate

mounting base

I

1

Front view

Needle

Felt

/

I

000

Front

view

I

1.

Remove cover

0

(left) of the cloth chip chute and screw

@

in

the detent plug for the silicon oil lubrication hole, mounted on the

lower left-hand section of the machine as observed from the front.

*

Checking the cartridgefilter and replacing

it

1.

After a long period of usage, cartridge filter

0

may

become clogged with dust.

If the machine is left in this state, the dirty oil may

fail to pass through cartridge filter

0

,

and the

machine may wear out abnormally, or a seizure may

result.

*

Cartridge filter

0

should normally be checked

once every six months, and cleaned or replaced

accordingly.

2.

Checking/replacement procedure

1)

Unscrew and pull out setscrews

@

.

Then

remove cover

Q

.

2)

Remove cartridge filter

0

and check it. If the

filter is found to be abnormal, clean the relevant

2.

Fit the needle cooler support onto needle guard supporting pin

Q

and

fix

the support firmly in place by tightening setscrew

0

Then, by placing lubrication joint

@

between two pieces of pack-

ing, attach the joint in the location where screw

@

was ln the

detent

plug

for the silicon oil lubrication hole using tile setscrew

provided.

(Caution)

The needle tip should come

in

contact with the felt when it is

brought toits lowest dead point.

Make

sure that the needle cooler does not come in contact with the

components, or replace cartridge filter

0

.

3)

Re-insert cartridge filter

0

into its proper

position and return the cover. Do not forget to

put back thesetscrewsand tighten them up.

-

*

Lubricating the needlecooler

1

Open looper cover

0

,

fill

the needle cooler

with

iilicone oil (available at extra cost) through

0

,

using the furnished oil feeder

2

Open fact? plate cover

@

.

remove plug

@

,

and

upp ply

s~llconeoil wlth the

011

feeder

I

Vot applicable to

MOG-25

16N)

3

lnflltrate sllicone oil also Into the

011

felt

~f

the

rndchlne

1s

~tdrted~rnrned~atelyafter lubrlcat~ngthe

nc.t.dle cooler

lower looper and the differential feed dog.

4-

MATPARTS

7.

OPENING/CLOSING THE COVER

~~~

~~

~-

-

~-

~

--~

---~--~

---.

*

Cloth plate cover

(

To open cloth plate cover

0

.

push down

cloth plate opening lever

@

.

To close the

cover, push it in the direction of the arrow.

*

Looper cover

~

--

To open looper cover

@

,

move the looper

cover in the direction of the arrow until

it

will

I

go back nofarther, then bring it down.

\-

Raise the looper cover when closing it.

Down

'

(Caution)

~~

For a fully-sunken table type, make sure

to

,\

-

lower waste chute opening

Q

beforeopening

the

looper

cover.

I

1-

---

~

-~

~

--

-

8.

ATTACHING NEEDLES

The standard needles are:

TV

x

64

#2

1

for

MOG-2504N,

DC

x

27 *I4

for

MOG-2514N.

TV

x

64

#19 for

MOG-25

16N

Attach

the needles according to the following procedure:

1. Bring needle clamp

0

to the highest position.

2.

Loosen needle clamp screw

@

,

and fully insert the needle into

the

needle clamp hole with the needle recess facing backwards

as viewed from the operator's side.

3.

Tighten the needle clamp screw.

MATPARTS

9.

THREADING THE MACHINE

Thread the machine according to the threading chart given below. (The same chart is on the inside of the looper cover.)

.

-

.

-

.

--

-

-.

-

--

.

-

.

-

.

-.

-

-.

-

1

:

MOG-2504N

I

MOG-2514N

I

(Caution)

Be sure to pass the double-chain stitch needle

thread through the needle thread take-up long groove.

(The outer thread is the overlock needle thread.)

-~

~~

~ ~

-

i

lntermed~ate

thread

guide

(Caution)

When using an untwisted thread such

'

as

wooly

nylon thread or

weak

thread,

do not

wind

it

round the intermediate

thread guide.

~~

-~

~-

-

~

-

-~--

~-

-

~-

-

- -

-

2

MATPARTS

10.

THREAD TENSION

Using the thread tension nut, adjust to an optimum thread tension according to your sewing conditions such as type of materials,

type and count of thread, etc.

11.

PRESSER

FOOT

PRESSURE

AND LIFTER

12.

ADJUSTING THE STITCH

LENGTH

-

~

-

----

-~

--

-~

-

--

~

-

,

.

. .

~--~~

.-

~~~

-~

- -

-

Adjust the pressure of the presser foot by turning

I.

Slowly turn the handwheel as you keep depressing pushbutton

0

,

presser foot adjust screw

0

.

When the adjust screw and you will find a point at which the pushbutton goes in farther.

is

turned clockwise, the pressure increases, while the

2.

With the above condition maintained, align the desired scale mark

pressure decreases when the screw is turned counter- on thz handwheel with white mark

@

on the belt cover.

clockwise.

3.

Reset the pushbutton after setting the dial.

When

you

turn presser foot assembly

Qb

side-ways.

bring down presser lifting lever

@

.

Whenever the

presser foot is returned to its original position, be

sure to bring up the presser llfting lever.

I

1

13.

LOCKING MECHANISM OF

FEED

ECCENTRIC CAM

--

.~

!

<;

~,

---!

When the machine is operated continuously (or when

I

fr'

'

-

;

kj

1

frequent change of the stitch length is not required).

I

@

..!

/

it will be better to fix the feed eccentric cam.

This

@

1

will prolong the life of the machine.

'

I

For

the

MOG-25l4N.

align

"L"

ox

the pulley with

!

the white marker line on the belt

caber,

and

for other

.

.,

I

models, align

"5"

with the white marker 6ne.

1

:,

,

I

/'

Remove rubber cap

Q

from the eccentric

i

-,

~i

-A

-W

1

mechanism cam.

p/'

;;-,-i

-~-

.,,T7

~

>--

1

Now, feed cam fixing screw

0

is

seen. Fix

the

i

>*-.

.

./

&:

,--

-_-

~s

'-

I

:/

-

'

jgy

1

feed cam by tightening the screw.

1

MATPARTS

14.

HEIGHT OF NEEDLE

When the needle bar is at the hghert polnt ofits stroke, the overlock needle po~ntsshould be 14

2

mm and

14

mm,

respectively

above the throat plate surface

-

--

-

--

-

---

MOG-2504N MOG-2514N

MOK-2516N

(Reference Left)

I

-

1

15.

SETTING THE LOOPERS

1

Most

retreated

I

*

Lower looper

-

1.

When lower looper

0

has gone back

farthest, it should be

distanced

2.7

to

3.1

mm

from overlock needle

Q

.

2.

When the lower looper is crossed with the

needle, the clearance between them should

be 0.05 to 0.1 mm.

3.

To make adjustment, loosen setscrew

Q

and move lower looper holder

@

.

Most

retreated

I

*

Double-chainlooper

1. When double-chain looper has gone

back farthest, it should be distanced

1.8

to

2

mm from double-chain needle

@

2.

The clearance between the double-chain

looper and needle should be

0.05

to

0.1 mm when they are crossed each other.

3.

To perform the adjustment, loosen set-

screws

@

and

@

.

--

*

Upper looper

1.

When upper looper

(b

has advanced farthest,

it should be

12.9

to

13.3

mm above the

throat plate surface.

2.

The clearance between

upper looper

0

and

lower looper

0

when

'

they are crossed each

other should be 0.05 to

1

O.2mm.

3.

Loosen setscrew

6

,

and adjust the position of

the upper looper.

After adjustment, tighten setscrew

B)

with

a

28

kg.cm torque.

[The specified torque can be obtained

by

fully

tightening the screw, holding the middle of the

supplied spanner (5

x

6)

@

.]

1

16.

DIFFERENTIAL FEED MECHANISM

I

1. Loosen differential feed lock nut

Q

.

Move lever

0

up for stretching stitch

or down for gathering stitch.

2.

When you want to move the lever only slightly, use differential feed minute

-

adjust screw

@

.

3.

Position

"S"

provides

a

differential feed ratio

oT

1

:0.64,

while it provides

1

:1

stretching stitch only for the

MOG-75

14N.

4.

Gathering stitch can be

se:

up to a differentla1 feed ratio of

1

:1.76,

and up to

1

:2.9

only for

MOG-25

14N

(possible up

to

1

:4

by adjusting the internal

mechanism). The figures marked

on

the differential feed scale are just a rough

indication.

MATPARTS

17.

PRESSER FOOT AND FEED DOG

1

~

-

*

Contact of the presser foot with the throat plate

top surface

Using adjust screw

@

,

perform adjustment so that the sole c~f

the presser foot evenly comes in contact with the top surface

of the throat plate when presser foot

0

comes down.

*

Height of feed dog

1.

Feed dog

0

is usually set so that its teeth protrude about

1.3

rnm

from the throat plate surface at the highest point in

its trajectory. Reduce the protrusion for light weight

materials.

2.

Use setscrew

@

to adjust the protrusion of the feed dog

teeth.

3.

Using setscrew

,

make adjustment so that differential

feed dog

Q

is level with the main feed dog.

4.

Adjust the height of auxiliary feed dog

by

setscrew

so that it is

0.5

rnm

lower than the main feed dog.

Front

up

p=YY1

line

'

(Q

*Tilt

of feed dog

1.

Loosen screw

Q

,

and turn eccentric shaft

0

in

thedirec-

tion of the arrow to make the feed dog front upor turn it

in the reverse direction to set the feed dog front down.

2.

The feed dog should be levelled when the dot engraved on

the eccentric shaft faces exactly to the line.

-

18. CHAIN LOOPER THREAD CAM (MOG-2516N)

Parallel

Loosen setscrew

B

,

and adjust chain looper thread cam

0

so that, when the needle is in the highest position of

its

stroke,

the flat part of chain looper thread cam

0

is in parallel to

the top surface of thread guide

@

.

Be sure that the chain

looper thread cam releases the looper thread when the needle

point is about

2

mm below the throat plate bottom surface.

i---

I

Approx.

2

mrn

19.

THREAD GUIDE

AND

LOOPER THREAD

TAKE-UP

The table below shows the standard demensions of the individ-

ual thread gu~desand looper thread take-ups when the upper

looper has gone back farthest.

r

7----

I

-

I--

-

1

..

__I

63

6

3

I

41

--

+

41

26

r.-.~

~.

.

F

I

26

+

-

A

--

-

~

-~

(;

4

-

~

41

!

26

1

44

1---

-

~~+

-

,

H

26.5

18

9

-

-I-

-

+

.

--

-~

+

.

J

I

1

17

*--.-

~

+.-.

-

~

~~.~--

-~-~

.

~

~.~--+

~

~-

---

J

22.5

19.5

*-

~

-&

.

--

~-

-+~-

-

~~

-

22.5

+

-

.

1

K

Y

1

:3

9

L~.~~.-~

-~

.--

.*

+

~-

.

1-

--

~ ~

-

58.5

(!.init

:

mm)

MATPARTS

-

20.

KNIVES AND OVEREDGE WIDTH

*

He~ght

of the lower knife

I

>e

,-TI

.iL',<

it.w and dtllust the helght

ot

lower kn~fe

0

SO

'I>\,

11,

zdg~

$\

tlush wlth thc throat plate \urtaie

*

Height of the upper knife

i..r\.;.

n

iriccrews

,

@

and performadjustment so that upper

A:;:!.:

@

.)\trlaps lower kn~te

0

hy

0

5

to

I

rnrn

when the

Ili3ptsr

kn~:-

i,

dt

its lowert point

*

Overedge width

iheirdgt. \+!dths of

4.8

through

10

rnrn dre provided by

<!!-lnglilg ri~cparts or

by

uslng hubclaha r~~vdels.(The overedge

uidth

u~ii

he

slightly larger than the kn~fecut width.)

Pi)

<,h

ingc

the overedge wldth.

1.

L.ooscnlng setscrew

@

,

push lower knife

0

to the left and

I1.x

It.

1

1.~1nsensetscrew

Q

and move upper knife

Q

as required.

tl~eni~u

it

3

Lllwcr the upper knife to its lowest point and Loosen set-

screw

@

.

Tighten setscrew

@

when the lower knife comes

In contact with the upper knife.

*

Resharpeningthe lower knife

When the lower knife has become dull, resharpen it as shown

in the figure left.

1

21.

NEEDLE

GUARD

I

~-

~p

-

*

For

1-Needle

and

2-Needle

Overlock Machines

An

overlock machine is equipped with

two

needle guards

0

and

@

.

I.

Position needle guard

0

so that it lightly comes in contact

w~thneedle

0

when the blade point of lower looper has

reached the center of needle

0

7

Position needle guard

@

so that it

is

1

mm lower than the

bottom surface of the throat plate

and

is distanced 0.1'mm

from needle

Q

when the needle is at its lowest point.

*

For

safety stitch machines

A

safety stitch machine has four needle guards

0

,

@

,

@

and

0

.

1

Position needle guards

0

and in the same manner as the

overlock machne explained above.

2.

Position needle guard

0

so that it lightly comes in contact

with needle

@

,

and position needle guard

0

so that it is

distanced

0.1

mm from needleewhen the needle is at its

point

1

lowest point.

I

MATPARTS

1

22.

TROUBLES AND CORRECTIVE MEASURES

CAUSES

1

CORRECTIVE MEASURES

I

1

Needle

breaking

i

I

I) Needle type is wrong.

!

(2)

h'eedle size is not correct.

I

(3)

Needle

is

not installed correctly.

i4)

Needle is not straight.

(5)

Keedle-to-needleguard relation is bad

-

1

t

61 Needle-to-looper relation

IS

bad.

T---..

2,

cloth

Is

not cut

(I)

Position of the upper and lower knife is

I

inadequate.

/

(21

Knife blade has worn out

,3

Use a specified needle.

0

Use a needle size suitable to the thread gauge

and type of fabrics.

3

Install the needle correctly (See

8).

0

Use a straight needle.

0

Correct the relation (See

2

1

).

c

Correct the needle to looper relation (See 15).

~

-

.

--

~

-

Adjust the knife position (See 20).

0

Sharpen the lower knife or renew the upper

knife.

3.

Stitch skipping

4.

Thread breaking

(

I

)

Needle-to-looper relation is wrong.

(2)

Looper blade is blunt.

(3)

Needle is threaded with S-twist (or left-

hand twist) thread.

(4) Thread tension is wrong.

(5)

Double chain looper thread tension is not

enough.

(

1

)

Quality of the thread is poor.

(2)

Thread is too thck for the needle size.

(3) Needle is installed in a wrong way.

(4)

Thread tension is too high.

(5) There is a scratch or bruise on the surface

of needle, looper, throat plate or needle

guard.

0

Correct the needle-to-looper relation (See

15).

0

Correct the shape of the looper blade using

an oilstone, or replace it.

0

Use a Z-twist (or right-hand twist) thread witb

the needle.

0

Adjust the thread tension (See 10).

0.

Correct the position of the chain looper threa~

cam (See 18).

0

Use a thread of good quality.

0

Select a suitable needle or thread.

0

Install the needle correctly (See 8).

0

Adjust the thread tension

0

Remove scratches and bruises using an oil-

stone or buffing machine.

5.

Double chain-off

thread stitcfung

failure

(MOG-25

16N)

6.

Puckering

7.

Irregular stitching

(I) Presser foot does not evenly act on the feed

dog.

(

2) Rear presser is shaking.

(3)

Needle thread and looper thread tensions

are not correct.

(4) Double chain looper is installed in a wrong

way

(

1

)

Needle is too thick

Thread tension is too high.

Pressure applied by the presser foot is too

high

or

too low.

Feed dog comes up too much from the

throat plate surface.

(5)

Knife fails to cut the fabrics sharply.

(6) Differential feed mechanism is not set

correctly.

(

1

)

Thread is not supplied smoothly.

1

0

Correct the relation of the presser foot with

the feed dog.(See 17).

0

Adjust the rear presser for smoothand

steady motion.

0

Adjust the thread tension (See

10).

0

Correct the double chain looper (see 15).

0

Select a suitable needle size for the thread

and materials.

0

Adjust the thread tension.

0

Correct the presser foot pressure (See

1

).

0

Lower the feed dog.

0

Sharpen the lower knife.

0

Correct the differential feed mechanism

(See 16).

0

Use smooth thread with even thickness or

(2)

Thread tension is too low.

(3) Needle is blunt.

(4) Pressure applied by the presser foot is

inadequate.

(5)

Height of the feed dog is wrong.

clean up the thread path.

0

Increase the thread tension.

0

Use a new needle.

0

Adjust the presser foot pressure (See 11).

0

Adjust the height of the feed dog (See 17).

MATPARTS

23.

SPECIFICATIONS

MOG-2504N MOG-2514N MOG-2516N

~

----

~ ~

Sewing speed (Max.)

I

5,500 s.p.m. 6,000 s.p.m. 6,000s.p.m. (FF6, FH6)

1

5,500 s.p.m. (FM6)

-.L-

----

-

_-

--_

_

.

_

__

Stitch length

2

-

5 mm 2-Smm 2-5mm

---

-

.-

..

a--

--

_

-

Needle gauge

I

2.0

rnm

4.8

mm

--

-

-*-.--

---

Overedge width 10

rnm

4.8,6.4 mm 4.8.6.4,

lOmm

Differential feed ratio

I

Gathering stitch

1

:

1.76

i

Gathering stitch 1:1.76

(Max.

1

:4) (Max. 1.4)

1

(Max.

1

14)

i

Stretching stitch1:0.64 Stretching stitch

1

:0.64

Needle

-

Presser foot

lift

Lubricating oil

(Max. 110.6)

1

(Max.

1

:0.6)

1

(Max. 1:0.6)

--

TV

x

64

1

DC

x

27

(standary

i

TV

x

64

1

(DC x

I

may be used)

(

Max. 9.0mm

-f--

Max. 8.0

-T

Max.

9.0

mm

JUKI

New

Defrix

Oil

No.

2

MATPARTS

MOG-2500N

SUBCLASSES

1.

SPECIFICATIONS

Sewing speed

(Max.)

Overedge width Needle :Presser

foot lift

(Max.)

I

MOG-2503N-ON6-3D0 15 mm

(for

splicing)

I

5,500 s.p.m. (max. 15mrn with

~

DC

x

27

#I6

~

materials open)

1

,

(for carpet)

I

4,500 s.p.m.

MOG-2505N-OM6-7E0

i

I

(for car mat)

I

~

2.

THREADING THE MACHINE

Thread the machine as illustrated below: (The same threading chart is provided on the inside of the looper cover.)

-

MOG-2503N MOG-2505N MOG-2515N

3.

STITCH TYPE

The stitch types of the three models are as shown below:

MOG-2503N MOG-2505N

MATPARTS

4.

ADJUSTMENTS

OF

NEEDLE

HEIGHT

AND

LOOPER

TIMING

1

I

1

r!

rn

I

.

1

%

0

-

.-

l

i

n

c!

in;i

N

Q

3

.E

g.;

0"OU

~5.22

U)

U)jU)l

i

1

___I-LA-.-~

i

$

9

n

s,

ZcEE

a.2

gz

:-%Eos!~

L

VI

-

3

z

1

9

-

I

2

g&cZ-

t

w

-

'+.

w

-

&

g

4

I

1

gg2530

42222

h

e,

b

g$+uw3,

30s

%$

2

I

2

/

a

1

a

;

I

!

111

I

:

hhh

0-

222

WNC(

o*

O*

8

o

2

0

-

--.I

I

1

;"!'a

jLA

,LO

(

v,

1

I

-+

+---

~

1

-

8

ZZ

.-

4

i-

-

;"?

aa~

a

g'~

2

-

G

-

C;

+

,m

d

,+

;&

..-.

3-r.

-

I

-

;--A7-

~

:

e,

-

!

0

I

/,,

I

?----.-.

*

I

IPl

iC4

N

;u

;;

2

I..

a-

I

E

/'

/

'

ia!q-cul

q..1!1<

i~rjip

_____-i

-

___

*

3

-

1

I

i

G!

1

I

z;

-

r

w

b*LZ

awaus@

8%3

A

32s

u+

wr

mB.2

2a.z

@

Uma

z

g.ci.9

@

GZ2

'

1

*X *X

3

*

3

4

VVV

h

-

WO

G$

mw

?-

d

-

V

,

--

9

;

z9;

A

WwW

I

,

!

I

39,

I

-ru

!

;

LO,

e!

.

--

-

NN

-

I.?$

r-m

mm

I

,

-

I

Sj

=.

--...

-

i

I:

3

2

N

ip?

iz

~2

i

*

id

i

I

t-+

-

+

2

im

'y

i

I

a

I

s!

a

I&

/od

*

I*

i.3

lc,

~

MATPARTS

5.

THREAD GUIDES AND LOOPER THREAD TAKE-UPS

The adjustments

for

the thiead guides and looper thread take-upswhen the upper looper is in

its

most withdrawn position are

shown

below:

-

~- -

-

--

-

~

--

-

~

-

Throat

plate

I1

'

2

i

l

_-_i--

15

-1

+

22

i

19

(unit: rnm)

((APPLICABLEONLY TO MOG-2505N)

1.

ADJUSTMENT OF LOWER

LOOPER

Adjust the lower looper so that it meets the following

dimension requirements when it is in the leftmost position

of its stroke.

2.

THREAD GUIDES AND

LOOPER THREAD TAKE-UPS

Perform adjustment to meet the following dimension require-

ments when the upper looper is in its most withdrawn

position.

Needle thread guide

i

I

1

I

Upper looper

1

I

A

Needle thread take-upguide thread guide

1

-

I

Upper looper thread guide

/

(right)

/

I

m

'

\

I

Lower looper Lower looper thread take-UP

I

5

thread take-up

l

(right)

d

l

9

MATPARTS

3.

ADJUSTMENT

OF

CLOTH GUIDE

A.

Cloth

Guide

(MOG-2505N-OM6-700

carpet)

Overedging width

The overedging width depends on the distance between the

needle entry and the guide sur-face of cloth guide

0

.

To

adjust the overedgil~gwidtll, loosen screw

@

,

and move

the cloth guide.

Presser foot

I

B.

Cloth

Guide

(MOG-2505N-OM6-7E0

for car mat)

Overedging width

I

Ib,

Presser foot

v

I

0

((APPLICABLEONLY

TO

MOG-2503N, MOG-2505Nj)

1.

ADJUSTMENT OF STITCH

LENGTH

The overedging width depends on the distance between the

needle entry and theguide surface of auxiliary hook

0

.

To adjust the overedging width. loosen screw

9

,

and move

the auxiliary hook.

((APPLICABLEONLY TO

MOG-2503Nj)

1.

CLOTH GUIDE PLATE

I

The pushbutton can be used for stitch lengths up to

5

mm.

For a stitch length exceeding

5

mm, perform adjustment

according to the following procedure:

(1)

Set the stitch length to

5

mm, using the pushbutton.

(2)

bosen locknut

0,

and move adjusting lever

@

down

to set it for the desired stitch length. After adjustment,

tighten the locknut.

(3)

When the stitch length scale is set to

"0".

a

stitch length

of approx.

5

mrn

is provided. When it

is

set to

"3",

a

stitch length of approx.

7

mm is given.

Cloth guide

plate

!

The cloth guide

plate

is

fixed with two

setscrews

(SS-7110510-SP)

~

-

..

~

.

-

~

-

--

.-

->

If

it

is necessary toguide cioth before the presser foot because

of

wider cloth edge cut

by

the knife. use the cloth guide plate

supplied with the machine.

MATPARTS

JUKI MOJ 2500N series User manual

Popular Sewing Machine manuals by other brands