Pfaff 438 Service Manual

®

438

Service

PFAFF

INDUSTRIEMASCHINEN

Manual

GMBH

KAISERSLAUTERN

Instructions

and

Illustrated

The

machine

which

has

been

I

Note:

Never

mightbedamaged

for

Adjusting

Guide

for

Tape-Recorded

we

had

In mind in drawing up

repaired,

but

useaneedle

by

still

needs

rise

the

C-clampofthe

the

Pfaff 438

Instructions

the

adjusting.

gauge

on

gauge.

following

the

Pfaff

instructions

438

because

is a

machine

its

needle

bar

Tools,

the

1

2

1

Gauges

Pfaff

438

setofscrewdrivers

setofwrenches

setofalien

cylindrical

feed

dog

gauge,

hook

bearing

wrapper

stripsofwhite

reelofadhesive

sewing

with

thread

and

from

screw

wrenches

pin, 32 mm

Order

bracket

System

paper

tape

Accessories

with

blades

7—14

mm

long,

No.

gauge,

438

needles,

Required

from

2-10

in

sizes

from

6 mm

dia.

91-129 995-05

Order

No. 91-129 996-05

No. 80

for

mm

wide

2—6

mm

No. 13-030 341-05

Adjusting

1.

Preparations

for

Adjusting

1.1 Determining the Different Needle Positions (Fig. 1)

1.1.1

The

bearing

plateatthe

needle

bar

endofthe

machine

conjunction with a 5-mm pin, determine the different needle positions.

1.1.2 Hole 1 =

1.1.3

Hole

1.1.4 Hole 3 = 0,25 mm (abt. .01")

1.1.5

Hole

Needle

bar

2 =

Topofneedle

4 = 1 mm (.04")

rise

stroke

position 2 mm (abt. Vsi")

bar

stroke

past

the

highest

past

the

highest

pointofthe

above

pointofthe

needle

has

four

the

bottomofthe

needle

bar

holes,

bar

stroke

which, in

needle

stroke

5

Fig. 1

1.2

Removing

1.2.1

Turn

out

remove

1.2.2

Takeupthe

moveitwithavacuum

the

screws

cover.

Cast-iron

Softhe

oil in

the

Cover

cast

needle

pump.

(Fig.

2)

iron

vibrating

cover

on

the

eccentric

backofthe

housing

machine

with a

sponge

arm

and

or

re

Fig.

2

1.3

Removing

1.3.1

Turn out screw 6 of the presser foot and remove the presser foot.

Various

Parts before

Adjusting

the Needle Bar

(Fig.

3)

1.3.2 Turn out screw 7 of the thread guide, too, and remove the thread guide.

1.3.3

Loosen

from

1.3.4

Turn

arm

1.3.5 Insert a new System 438 needle and push it up as far as It

and

the

out

screw

presser

the

remove

8 of

three

bar

the

bushing

alien

cover.

slack

screws

thread

control

by pulling It

9 of

the

and

remove

downwards.

coveronthe

the

thread

slack

undersideofthe

will

go.

control

machine

Fig.

3

2.

Centering

the

NeedleInthe

Needle

Hole in

Sewing

Direction (Fig. 4)

2.1 Bring

2.2

Loosen

2.3

Loosen

2.4

Turn

is

centered

2.5

In

this

the

needle

jam

alien

eccentric

position

nut

in

screw

stud

the

bar

10.

12 on

needle

tighten

to its

11atthe

the

holeinsewing

alien

lowest

position.

bottom

right-hand

screw11as

of

the

sideofthe

direction.

wellasjam

needle

bar

frame.

machine

nut

arm

until

10 firmly.

the

needle

Fig.

4

3.

Setting

3.1

Remove

3.2

Raise the needle

3.3

Block

of

3.4

Loosen clamp screw 15 at the bottom end of the stabilizing rod.

3.5

Loosen screw 18 (accessible from the back of the machine arm)

clamp

3.6

Then

Turn eccentric stud 17 to

3.7

the

Stabilizing

the

face

the

machineInthis position by inserting the

the

bearing

crank

loosen

plate.

19 in

jam

Rod

Paraiiel

cover.

bar

to Its highest point.

the

machine

nut

16.

set

stabilizing rod 13 parallel to the needle bar.

arm.

to the

Needle

Bar

(Fig.

5)

5-mm

cylindrical pinInhole 2

Be careful that you don't turn the eccentric stud by 180 degrees.

3.8

Hold

eccentric stud 17 in this position and tighten jam nut 16 securely.

3.9

Push up stabilizing rod 13 as far as It

will

go, making sure that the eccentric

stud enters the recess at its top end (see arrow in Fig. 5) and tighten clamp screw

15 on

clamp

crank19securely.

3.10

Remove the cylindrical pin from the bearing plate.

3.11

Bring the needle bar to its lowest point and tighten screw 18 on the back of the

machine

firmly.

which

secures

Fig. 5

4. Adjusting

4.1 Zeroing

4.1.1 Flick

4.1.2 Loosen straight-stitch regulating

maximum

the

Stitch Width Control

the

Needle for

needle

position lever 20 to its central position.

Straight

Stitching (Fig. 6)

screw23and

stitch

width.

stop

screw

24 for limiting

the

4.1.3 Loosen clamp screw 26 of locking lever 22 and let lever 22 swing back until its

springiscompletely

4.1.4 In this position, tighten

4.1.5

Move

stitch

width

4.1.6

towards

Turnonthe

lever

21 to

"0".

the

4.1.7 In this position,

will go

4.2

Adjusting

4.2.1

Move

4.2.2

Loosen

4.2.3 Adjust

flangeofthe

4.2.4 In

this

and

the

stitch

both

the

position,

tighten

width

scale

master

left until

push

Stitch

screws

stitch

tighten

relaxed.

clamp

screw26again.

lever

21

counter-clockwise

switch

and

let

the

needle

straight-stitch regulating

it.

Width

Scale

(Fig. 6)

lever21to

25ofthe

until

width

the

lever.

both

the

rightasfarasit will

stitch

zero

mark on

screws

the

bar

width

25 of

as

machine

stops

swinging

screw

scale.

the

scaleisopposite

the

scale

far

as

it will

run slowly.

sideways.

23 to

go.

securely.

go,

that

Move

stitch

the

rightasfarasit

the

mark on

means

width

the

Fig. 6

4.3 Limiting the

4.3.1

Move

mark

4.3.2 Move it will go

li for

whose hole is smoller thon the widest needle throw, limit the

ol the needle hole rother than the groduotion mark on the stitch width scale.

4.4

Adjusting

4.4.1 Loosen Make

4.4.2 Pull

locking

Maximum

stitch

\wjdth

lever 21 to the left until the mark on its flange is opposite the

indicating

stop

cerfoin

clamp

sure

the

screw/ 24 which limits

and

tighten

sewing

operations your

the

Locking Lever (Fig. 7}

screw

the

pressure

lever22forward

Stitch Width (Fig. 7)

maximum

it.

26 of locking lever 22.

stitch

the

machine

springinthe

until it

w/idthonthe

maximum

locking lever

contacts

should

stitch

hove

stitch

scale.

widthtothe

been

equipped

stitch

does

width

with

width according to the width

not fail out.

lever

21.

4.4.3 In this position, turn hinge stud 27 in or out until locking lever 22

right

amount

of play.

Then

tighten

clamp

screw26securely.

leftasfar

a needle piole

has

just the

as

Fig.

7

5. Adjusting

5.1

Make

sure

width

leveristurned

5.2

Bring

the

5.3

Loosen

5.4

Now

turn

ways.

5.5

Retain

the

that

needle

jam

nut

eccentric

Needleinthe

the

stitch

to

"0".

bar

to its

10 of

eccentric

stud28until

stud

28 in

width

lowest

this

Needle

lever

stud

the

position

Hole

is stiil In its

position.

28 on

needle

and

Sideways

the

undersideofthe

is

centered

tighten

(Fig. 8)

central

jam

position

in

the

nut

and

machine

needle

10 firmly.

the

hole

stitch

arm.

side

Fig.

8

6.

Adjusting the Needle Throw (Fig. 9)

6.1

Loosen

both

screws

29 of the

needle

vibrating

eccentric

mit the eccentric to be turned on its shaft against strong resistance.

6.2

Bring the needle bar to its highest point. Insert the

bearing

tion.

6.3

Move

Vii")

6.4

Turn the eccentric on its shaft

stitch

6.5

Pull the cylindrical pin out of the bearing plate.

Do not tighten screws 29 of the needle vibrating eccentric yet.

6.6

2®(i((0

plate,

thus

blocking

the

the eccentric on its shaft

between

width

its

right-hand

leverismovedtoand

side and the

machine

until

with

the needle bar in its highest posi

there is a clearance of about 5.0

wall

of the casting.

the needle bar ceases

fro.

just

sufficiently

5-mm

pin in hole 2 of the

vibrating

to per

mm

while

(or

the

Fig. 9

7.

Adjusting the Needle Throw in Relation to the Central Needle Puncture

7.1

Move the needle position lever to its central position and the stitch width lever

to

"0".

7.2

Place a piece of white paper under the needle. Turn the balance wheel in sewing

direction until the needle

a

little.

7.3

7.4

7.5

7.6

7.7

7.8

Hold the

mum

Rotate

stitched

Remove the

rection Place

the

Turn

paper

Since

the

paper

stitch

the

into

one

the

paper

first

hole.

the

stitch

again. the

eccentric

width.

balance

the

paper

complete

two

punctures must be moved in

rotate

the

eccentric

7.9

After you

(see

arrow

have

in Fig. 10) up

in its original position and turn the stitch width lever to the maxi

paper

under

width

screws

slightly on its

completed

has

wheelinits

again.

pierced the

normal

paper

slightly and then raise the needle

directionofrotation

until

from under the needle, turn the balance wheel in sewing di

turn

and

flick

the

needle

levertothe

29 of

shaftinthe

while

moving it

the

against

stitch width lever

again

and

position it so

widest

stitch

and

the

needle

vibrating

eccentric

direction in which

order

to obtain a symmetrical stitch pattern. (Don't

endwise

adjustment,

the

eccentric.

on its

tighten

screws29and

let

the

shaft.)

back that

needle

are

the

to "0".

the

still

two

the

needle

stitch

push

needle

loose,

outer

the

(Fig.

enters

into

needle

circlip

10)

has

ttxe

move

1 <

) Fig. 10

10

8.

Adjusting

8.1 Fixing

8.1.1 Loosen both

8.1.2 Turn

21tothe

the

needle

the

Needle

Position

Left

Needle

needle

Position (Fig. 11)

position limiting

position lever 20 to its

maximum

stitch

width.

Lever

screws30and

central

position

31. and

flick stitch width lever

8.1.3 Turn the balance wheel in sewing direction until the descending needle is posi

tioned

above

the

left

endofthe

8.1.4

Placeapieceofwhite

adhesive

8.1.5

Turn

the

paper

tape.

balance

lightly.

paper

wheelinsewing

8.1.6 Turn stitch width lever 21 to "0"

until the point of the

paper.

8.1.7 Push

Leave

needle

limiting

position limiting

needle

screw31loose,

needle

hole.

over

the

needle

direction

and

until

push

is positioned right

screw

30 up

against

however.

hole

and

the

needle

position lever 20 to

above

the needle puncture in the

its

stop

fix it to

has

the

machine

stitched

and tighten it firmly.

with

into

the

left

Fig.

11

8.2 Fixing

8.2.1 Flick

to

the

8.2.2

Rotate tioned

8.2.3

Turn into

8.2.4

Turn

until

8.2.5

Push

the

needle

maximum

the above

the

stitch

the

needle

paper

Right

Needle

position

stitch

balance

the

right

balance

wheelinsewing

lightly.

width

lever21to

pointofthe

position

Position

lever

width.

(Fig. 11)

20 to its

wheelinsewing

endofthe

"0"

needleispositioned

limiting

screw31against

central

direction

needle

direction

and

push

position

until

hole.

until

needle

above

its left

and

the

position

the

turn

descending

needle

stop

and

stitch

width

lever

needleisposi

has

again

lever20to

puncture

the

made

tightenitsecurely.

21

stitched

right

last.

Fig.

11

12

9. Adjusting the Stitch Length Scale Ring

9.1 Loosen the scale ring screw (see arrow).

(Fig.

12)

9.2 Turn the stitch length dial next to the

scale

ring in the direction in which the

reverse-feed control is caused to move downwards, turning it as far as it will go.

9.3

Turn

the scale ring so that its "0" mark is exactly in line

mark

on

the

reverse-feed

9.4 In this position tighten the

control.

scale

ring screw firmly.

with

the graduation

Fig.

12

13

10.

Zeroing

the

Feed

Motion

(Fig. 13)

10.1 Unscrew the

collected

10.2

Turn

the

10.3

Loosen

10.4 Rotate

gear

and

the

stitch

length

both

ciamp

the

feed regulating

case

foam-piastic

screws

makesnoperceptible

10.5 In this position, tighten

cover, making

padisremoved.

dialto"0".

32 on

crank

sure

the

feed regulating crank.

on its shaft until

movement when you turn

both

clamp

screws

32 of

that any oil that might run out is

the

balance

the

feed regulating

feed rock shaft

wheel.

crank

crank.

o

Fig.

13

14

11.

Adjusting the Feed Driving Motion (Fig. 14)

11.1

Loosen

both screws 33 on the feed

driving

eccentric just sufficiently to permit

the eccentric to be turned on its shaft against strong resistance.

11.2

Rotate the balance wheel until the needle bar is positioned about 1.0 mm

past

its

highest

11.3

To block the machine in this position, insert the cylindrical pin in hole 4 of the

bearing

11.4

Set

11.5

Turn the feed driving eccentric on Its shaft until its notch points forward.

11.6

Continue turning

plate.

the

machine for its

point.

the

longest

feed

driving

stitch.

eccentric

until

the

feed

rock

mains completely motionless when the reverse-feed control Is moved up and

down.

11.7

Hold It in this position, making

become

11.8

Turn

Pull the cylindrical pin out of the hole in the bearing plate and tighten the

11.9

feed

wedged

the

stitch

driving

sideways

length

eccentric

dialto"0".

screw

and

tighten

firmly.

sure

that the feed driving eccentric

oneofthe

screws

33.

shaft

crank

does

second

(V64")

re

not

Fig.

14

15

12.

12.1

12.2

12.3

12.4

12.5

12.6

Adjusting Turn

the Loosen Turn

the

past

the

pin in

Rotate

at

its

lowest

Keep

it in

eccentric,

tion.

Remove

of

the

stitch

both

balance

top of its

hole

the

feed

this

making

the

feed

Feed

length

screws

wheel

stroke

3 of

the lifting

point.

position

sure

cylindrical

lifting

eccentric.

Lifting

dialto"0".

34ofthe

until

and

bearing

eccentric

and

that

pin from

Motion

(Fig. 15)

feed

lifting

eccentric.

the

needle

bar

has

reachedapoint

retain it in this position by inserting

plate.

on its

shaft

until

the

feed

tighten

the

two

the

accessible

discs

areupagainst

bearing

plate

screw34of

and

tighten

the

lifting

feed

the

0.25

the

shaft

the

lifting

second

mm

(.01")

cylindrical

crank

feed

lifting

connec

screw

Is

Fig. 15

16

13.

Setting the Presser Foot at the Correct

13.1

Replace

alien

13.2

Push the slack thread control on the presser bar bushing so that it

struck

set

13.3

Screwonthe

13.4

Lower

the

cover

on the underside of the

screws.

by the needle bar

screw.

presser

when

footaswell.

the needle into the needle hole and make sure the needle position lever

it has

Height

reached

(Fig.

machine

its

16)

lowest

is in its central position and the stitch width lever points to "0".

13.5

Loosen

13.6

Raise the presser foot and push the feed dog gauge under it.

13.7

Raise

13.8

Adjust

slot

13.9

Push the presser bar

clamp screw 35

the

presser

the

presser

exactly.

which

bar

lifter.

foot

sidewayssothat

lifting

is partly concealed in the front part of the

the

needleiscenteredInthe

bracket downwards as far as it

clamp screw 35. Then remove the gauge from under the presser foot.

(There should now be a clearance of 7.0

foot

and

the

needle

plate).

mm

(abt.

arm and

'Az")

tighten

point

and

will

go and tighten

between the presser

the three

will

not be

tighten

machine.

needle

Its

Fig. 16

17

14.

Adjusting

14.1

Turn

(.01")

in

14.2

Set

14.3

Loosen

14.4 Loosen both

14.5

Place line with the front

lifter to let

14.6

Center

the

Feed

Dog (Fig. 17)

the

balance

wheel

until

the

needle

bar

has

reachedaposition

past its highest point and block the machine by inserting the cylindrical pin

hole

3 of

the

stitch

both

the

bearing

length

clamp

feed dog

the

presser

feed

doginthe

plate.

dial on

screws

"0".

36 on

37 on

gaugesounder

and

rear

edgesofthe

foot

downonthe

feed

the

slot

feed

lifting

feed rock

the

shaft

presser

needle plate. Lower

feed

dog

lengthwise.

shaft

crank.

crank, too.

foot that both its

gauge.

14.7 Turn the feed lifting shaft crank until the feed dog is up against

of

the

gauge.

14.8 Turn

14.9 Tighten both clamp

14.10 Also tighten both clamp

14.11 Remove the feed dog

eccentric

set

paralleltothe

that

the

outofthe

bushing 38 below

feed

dog

bearing

undersideofthe

screws

37 of the feed rock shaft crank securely.

screws

still

contacts

gauge

plate.

the

from under the

the

feed rock shaft crank until

feed

dog

gauge.

36 of

the

feed lifting shaft crank, making

gauge.

presser

foot and pull the cylindrical

ends

the

presser

the

feed dog is

0.25 mm

are

bar

underside

sure

in

Fig. 17

18

15.

15.1

15.2

15.3

15.4

15.5

15.6

15.7

15.8

15.9 In

Adjusting

Loosen

right.

Strip

Loosen

Unscrew

Remove

Loosen

taper

the

bobbin

the

alien

keyofthe

headofthe

Screwonthe from

the

front.

Turnormove

tacts

both

the

this

position,

gauge.

Hook

Bearing

clamp

screwonthe

case

two

hook

bed

slide

needle

screw39on

hook

alien

screw

hook

(See

the

hook

vertical

firmly

position

set

screws

and

plate

and

bearing

lightly with a

bearing circle

bearing

and

tighten

Bracket

(Fig. 18)

bobbin

finger.

and

pull

remove

the

feed

bedplate

it.

bracket

bracketsothat

in Fig. 18.)

bracketinsuch

horizontal

alien

surfacesofthe

sorew

case

opener

the

sewing

dogaswell.

(see

circle

underneath

hammer.

numbers

39 of

in Fig. 18)

a way

the

and

hook

this

438

that

gauge.

taper

swing

off its

screw

and

the

key

the

lattertothe

shaft.

and

by

tapping

439

canberead

hook

and

release

shaft

remove

the

con

the

Fig. 18

©

19

16.

Adjusting

the

Sewing

Hook

16.1 Place the sewing hook without bobbin

its

point

is at

the

top.

16.2 Hold

the

sewing

hook

steady

while rotating

bar has passed its lowest point and

16.3

Insert

the

cylindrical pin in hole 1 of

case

on the hook shaft in such a way that

the

has

risen 2.0 mm (abt.

the

bearing

balance

wheel until

Vs*").

platesothat

the

needle

machine

blocked in this position (needle rise position).

16.4 Make

width

sure

lever

the

needle

pointsto"0".

position lever is still in Its central position and the stitch

16.5 Tighten one of the hook set screws just sufficiently to allow the sewing hook to

be

turned

on its

shaft

against

16.6 Turn or move the sewing hook until there is a clearance of about

strong

resistance.

0.1

mm

(.004")

between the hook point and the needle. Make sure that the point of the sewing

hook is positioned

16.7 In this position, tighten both hook

16.8 Remove the cylindrical pin

16.9 Screw on the bobbin

the bobbin

tween

its

front

exactly

behind

the

needle.

set

screws

from

the hole of the bearing plate.

case

position finger so that it is positioned in the slot of

case

base and that there is a clearance of about 0.5

edge

and

the

bobbin

case

firmly.

base.

mm

(.02")

be

is

20

17. Setting ttie Needle Bar at the Correct Height (Fig.

17.1

Flick

the stitch

width

lever to "0" and the needle position lever to its left position.

19}

17.2 Rotate the balance until the hook point Is positioned exactly behind the needle.

17.3 Loosen both clamp screws 40 on the needle bar connecting stud.

17.4 Push the needle bar up or down until the hook point is positioned 0.5 mm (.02")

above the top of the needle eye

(see

circle in Fig. 19).

17.5 In this position, tighten both clamp screws 40 securely, making sure that the

thread

guideofthe

needle

holder

points

forward.

Fig. 19

V

21

18.

18.1

18.2

18.3

18.4

Tensioning

Loosen Move

middleofthe

Rotate

ciently running.

In

this

screw

the

taut,

position,

the

Driving

41 of

eccentric

sprocket

eccentric

butbecareful

tighten

Beltinthe

the

eccentric

bushing

endwise

driving

the

without

nottotensionittoo

screw

41 of

Gear

Case

bushinginthe

until

the

bobbin

case

movingitendwise

the

eccentric

(Fig. 20)

gear

driving

opener

muchasthis

bushing

case.

beltispositionedinthe

eccentric.

until

the

belt

is suffi

would

cause

hard

securely.

o

u

/

Fig. 20

22

19.

Adjusting the Bobbin

Loosen alien

19.1

opener

19.2

Push

underneath.

opener

19.3

Turn the

in line with

19.4

In

this of 0.8 mm (.03") the

bobbin

19.5

19.6

19.7

this

In

Turn

leftofits

Now

turn

until

there

finger

circle

19.8

In

this

sure

that

shaft

the

bobbin

Then

finger

eccentric

the

position,

case

position,

the

balance

stroke.

the

is a

and

the

of Fig. 21).

position,

the

Case

screw

which is

case

pushupthe

towards

Opener

42 of

locatedinthe

opener, which is still swung out,

the

right until it

the

eccentric

(Fig. 21)

eccentric

hook

bushing while swinging

contacts

bushing in such a way that the top

inner

sideofthe

push

the

between

(see

lower

tighten

opener

clearanceofabt.

wheel

finger

alien

until

right wall of

tighten

bobbin

ciamp

case

bobbin

eccentric

the

bottom

circle

of Fig. 21).

screw

the

bobbin

together

the

openerisup

with

0.3

position

screw

case

bushing

edgeofthe

42 of

mm (.01")

slotinthe

43 of

against

bearing bushing of the bobbin

bearing

the

bracket.

against

lug of

the

bobbin

clamp crank

bobbin

edgeofopener

base

(see

middle circle of Fig. 21).

case

the

endwise

the

bobbin

opener

eccentric

opener

case

between

bobbin

the

clamp

until

there

finger

bushing

fingerisat

base

the

bobbin

case

opener

crank

is a

and

firmly.

the

towards

case

base

firmly,

underneath.

case

finger is

clearance

the

rim of

extreme

the

position

(see

upper

making

case

base.

right

Fig. 21

A

23

20. Adjusting

20.1

Loosen

20.2

Turn turned

20.3 Turn the

risen

20.4 Insert

this

20.5 Now turn the

extreme

20.6 Remove

the

Bobbin

the

three

the

screwinthe

on its

shaft

balance

2 mm

(abt.

the

cylindrical pin in hole 1 of

position.

Case

screws

against

wheel until the

V64").

eccentric

right

of its

stroke.

the

cylindrical pin from

Opener

45 of

middleinjust

strong

Eccentric

the

resistance.

needle

(Fig. 22)

bobbin

case

opener

sufficientlytoallow

bar

has

the

bearing

on its shaft until the bobbin

the

bearing

plate.

passed

plate

case

eccentric.

the

eccentric

its lowest point and

to block

opener

the

machine

finger Is at the

to

be

20.7 Tighten the three screws 45 of the bobbin case opener eccentric, beginning with

the

screw

in

the

middle

in

Fig.

22

24

21. Adjusting the Oil Chedt Valve (Fig. 23)

21.1

Loosen

oil

check

valve

screw

46.

21.2 Push the actuating plunger of the centrifugal governor to the left as far as it

will

go.

21.3 Adjust the position of the oil check valve until there is a clearance of 1.0 mm

(.04")

between the valve rod and the actuating plunger.

21.4 In this position, tighten oil check valve screw 46 securely.

21.5 Replace the foam-plastic pad in the gear case and position it so that the cast

iron fin enters the smallest cutout in the pad.

21.6

Clean

the gear case gasket and screw on the gear case

screws

evenly

crosswise.

cover.

Tighten

the

Fig. 23

25

22. Inserting

22.1

Loosen

22.2

Insert

in Fig. 24).

22.3

Tighten

the

Oil

alien

screw47on

the

small

alien

screw47securely.

Tubeinthe

bent

copper

Oil

the

bedplate.

tubeinthe

Retainer

Ring (Fig. 24)

holeofthe

oil

retainer

ring

(see

arrow

Fig. 24

26

23.

Adjusting

the

Slack

Thread

Control

(Fig.

25)

23.1 Flick

leverto"0".

23.2 Bring

23.3

Loosen

23.4

Adjust

the

holeinthe

23.5 In

this

needle

Special sewing

or

lower.

the

needle

the

needle

screw8of

the

positionofthe

lower

edgeofthe

thread

position,

barisopposite

position

bar

tighten

operolions

lever

to its

central

to its

lowest

point.

the

slack

thread

control.

slack

thread

controlonthe

slack

thread

control

guide

(see

circle

in Fig. 25).

screw

8 of

the

centerofthe

may make it neccessary however, to set the slock

wire is in

slack

position

thread

presser

line

control,

control

and

with

turn

the

bar

bushingsothat

the

top

making

wire.

thread

stitch

width

edgeofthe

sure

that

control higher

the

Fig.

25

27

24.

Adjusting

(This odiuslmenF

24.1

Take

out

towards

24.2

Replace

24.3

Lower

the

24.4

Loosen

the

left

spring

action,

24.5

Operate

24.6

Place

the

24.7

Lower

the

gauge.

24.8

Loosen

24.9 Move

24.10

24.11 Turn

Turn

tighten

the

24.12 Remove

24.13 Swing the

24.14 Tighten release ing rod

ed

to Its

clearanceofabout

the

Tension

does

the

four

the

right.

the

needle

presser

clamp

screw

apertureinthe

pushitdownasfarasIt will

the

presser

feed

presser

screw

49onthe

cam

on its

presser

tension

screw49securely.

the

feed

presser

clamp

shaft

contacts

crank

is likewise up

highest

Release

nof

applytomachines

screwsinthe

plate

without

bar

lifter.

48 on

machine

bar

lifter to

dog

gauge

under

bar

lifter to let

tension

shaft

until it Is exactly

bar

lifter

upwards

release

dog

cam

gauge

bar lifter down to lower the

screw

48 securely, making the

face

point,

the

0.5 mm (.02")

(Fig. 26)

arm

screwingItdown,

the

connecting

arm. If

raise

the

release

until a

until it

from

under

sideofthe

against

tension

the

should

between

equipped

rear

the

presser

cam.

contacts

the

machine

casting.

with

subcl.

cover

and

rod

crank

connecting

go.

presser

foot with Its

foot

opposite

noticeable

the

presser

sure

that

(With

now

be

both

tension

-900

threod

swing

the

however.

which is

rod is not pulled

foot.

recess

down

into

the

tension

resistance

tension

release

foot.

foot onto the

the

circllp on

casting,

the

released

and

presser

discs.)

trimmer)

rear

accessible

up.

the

recessofthe

release

Is felt.

plunger

needle

the

that

the

bar

so

that

cover

lifter

there

away

through

down

plunger.

and

plate.

tension

connect

rais

is a

by

48

:?

28

Fig.

26

25.

Adjusting the Knee Lever (Fig. 27)

25.1

Limiting

25.1.1

Place

25.1.2

Operate the presser bar iifter to lower the presser foot onto the gauge.

25.1.3

Push

25.1.4

Loosen

25.1.5

Turn

25.1.6

Push

this position.

process).

25.1.7

In this position, turn stop screw 51 in aii the way and let the knee lever return

to its

25.1.8

Turn the stop screw out

25.1.9

Operate the knee lever now until it contacts the stop screw and remove the

gauge

(The

limited to 8,0 mm

25.2

Adjusting

25.2.1

Remove

25.2.2 Loosen both Jam

25.2.3 Turn connecting

25.2.4 Hold the

25.2.5 Pull

the

Knee

the

feed

dog

the

knee

lever

the

jam

stop

screw51outafew

the

knee

lever

(Make

normal

clearance

the

from

under

the

needle

rear

link when you

rear

knee

position.

Knee

nut in until

nut

lever

Lever

Motion

gauge

under

the

into

its

nutonstop

sideways

socket.

screw

turns.

until a

presser

51 which limits

foot with its

noticeable

sure the presser foot is not raised

one

turn and tighten the jam nut.

the

presser

between the

(abt.

Lever

plate.

nuts

50 on

steady

out

foot.

presser

Vu").

Play

the

there

push

foot and the needle plate has thus

connecting

is a

the

knee

link of

noticeable

lever lightly.

with a wrench and tighten the front jam nut.

of its

socket

again.

the

knee

resistance

the

knee

play

between

recess

down.

lever

is felt

from

the gauge in the

lever

the

motion.

and

socket.

nut

hold it in

been

and

the

Fig.

A

27

29

26. Adjusting the Thread Check Spring and the Slack Thread Regulator

26.1

Loosen both screws 52 just sufficiently to enable the tension barrel with the

thread check spring to be turned in the tension bracket.

26.2

Rotate

the

about

7.0 mm

Special sewing opefotions moy

26.3

The

tensionofthe

ing

the

tension

26.4 Loosen both

tension

barrel

(V32").

thread

stud.

screws53and

until

the

strokeofthe

mokeitnecessory

check

springisregulatedinthe

push

the

to choose a longer or shorter stroke.

slack

thread

check

usual

regulatorupas

spring

manner

farasit will go.

(Fig.

28)

measures

by turn

26.5 In

this

position,

The setting of the slack threod regulator is diiefly dependent on the type of thread and material

being used and has to be odjusted occordingly.

tighten

both

screws53securely.

K 30

Fig.

28

Adjusting

the

Bobbin Winder Pulley (Fig. 29)

Engage the bobbin winder by pushing against its spindle.

screws

Loosen both

of

the

machine

54 (which can be reached through the

arm).

Move the pulley on the arm shaft so that it

reliably when the bobbin winder is

does

not

contact

Tighten both

the friction wheel when the bobbin winder is disengaged.

screws

54 in

the

engaged.

pulley securely.

will

drive the bobbin winder spindle

Make sure, however, that the pulley

aperture

on the back

Swing the cover on the back of the machine arm back to its normal position and

secure

it in

place

with

its

four

screws.

Loosen

Fig.

Move

Then

29).

the tighten

screw

regulating

55 of

screw

the

regulating

studtothe

55 firmly.

studinthe

right

for

less

threadorto

bobbin

winder

the

latch

left for

(see

more

circle

thread.

of

28. Filling

the

Oil

Reservoirs

28.1 Fill

28.2

28.3

about

100

com

(or 6cuIn) of Pfaff

the

needle

vibrating

Clean

the

contact

screws.

FIN

Pfaff

sewing

a

holeInthe

top

mark.

When replenishing the oil loter, oil flows through on overflow duct from the hook oil reservoir

into the needle vibrating eccentric housing. Top up the oil until the oil level has reached the

top mark on the oil sight glass of the hook oil reservoir.

eccentric

surfaces

housing

of

the

machine oil No. 280-1-120110 Into

oil

sight

glassonthe

sewing

from

cast-iron

front of

machine

the

backofthe

cover

the

machine

oil No. 280-1-120110 Into

machine.

and

screwIton

the

hook oil reservoir through

arm

until It

with

reaches

Its

two

the

32

29. Regulating the Hook Lubrication

29.1

Turn

oil

regulating

29.2 Turn on the master switch and let the machine run for about one minute.

29.3

Remove

cutout

29.4 Let the machine run for about ten

of

29.5

To regulate the

be

and

spray

required.

the

holditthere.

oil

needle

opposite

flowofoil

screw56in

plate,

the

(Fig.

30)

completely,

then

placeapieceofwhite

seconds.

hook raceway.

to the

sewing

Check to

hook,

turnitout

paper

seeifthere

turn

screw 56 in or

halfaturn

over

the

again.

needle

Is a thin line

plate

out,asmay

29.6 Replace the feed dog and the needle plate as well as the face cover, the thread

guide

and

the

bed

slide.

Fig.

30

33

Important

When

the

brating

Pfaff

sewing

into

operation

Lubricating

Pfaff 438 is

eccentric

machine

for

Pointers

made

ready

for

shipment,

housing. It is absolutely

oil No. 280-1-120110 into

the

first time. (A sticker on

the

necessary

this

the

oil is

drained

that you fill 100

housing

machine

before

arm

from

the

needle

vi

ccm

(6 cu In) of

the

machineisput

servesasa reminder).

Replenishing

she

has

to do Is

topupthe

The

gear

case machine been place

When

pinion

Order

oil

opened

the

Important

the

greaseinthe

No.

the

oil in

the

hook

stick

the

spoutofthe

oil until

two

underneath

No.

280-1-120108

for

performing

foam-plastic

note:

the

oil level

the

Use

certain

pads

only

machineisoverhauled

hook

bevel

280-1-120199.

oil

reservoir

oil

has

reached

bedplate which

contains

hastobe

adjustments.Inthis

No.

91-168

oil No.

280-1-120108Inthe

thoroughly,

gear

case.

canbedonebythe

can

into

the

holeinthe

the

top

markonthe

about

changed

393-05

and

put2ccm

This

grease

130

ccm(8cu

only

case,

No. 91-168

gear

operator

hook

oil

when it is

recommended

394-05

case.

the

oil

sight

in) of

herself.

reservoir

glass.

Pfaff

gear

also.

sewing

case

(abt. Va cu in) of Molykote 350

maybeobtained

fromusby

All

and

has

to

re

34

Contents

1. Preparations for Adjusting 1

1.1 Determining the Different Needle Positions 1

1.2 Removing the Cast-Iron Cover 2

1.3 Removing Various Parts before Adjusting the Needle Bar 3

2. Centering the Needle in the Needle Hole in Sewing Direction

....

3. Setting the Stabilizing Rod Parallel to the Needle Bar 5

4. Adjusting the Stitch Width Control 6

4.1 Zeroing

4.2 Adjusting the Stitch Width

4.3 Limiting

the

Needle

for Straight Stitching 6

Scale

the

Maximum Stitch Width 7

4.4 Adjusting the Locking Lever 7

5. Adjusting the Needle in the Needle Hole Sideways 8

6. Adjusting the Needle Throw 9

7. Adjusting

8.

Adjusting

8.1 Fixing

8.2 Fixing

9. Adjusting

10. Zeroing

11.

Adjusting

12. Adjusting

13. Setting the

14. Adjusting

15.

Adjusting

16.

Adjusting

17. Setting

18.

Tensioning

19. Adjusting

20.

Adjusting

21.

Adjusting

22. Inserting

23.

Adjusting

24.

Adjusting

25.

Adjusting

25.1 Limiting

25.2

Adjusting

26. Adjusting the Thread Check Spring and the

27.

Adjusting

28. Filling Regulating

29.

Important

the

Left

the

the the

the

Lubricating

Needle

Right

Needle

Stitch Length

Feed

Presser

Feed

Hook Sewing

Needle

the

Driving

Bobbin

Oil

Check

Oil

Tubeinthe

Slack

Tension Knee

Knee

Lever

Knee

Bobbin

Oil

Reservoirs

Hook

Throw in Relation to

Position

Lever

Position

the

Central

Needle

Puncture

. 10

Position 12

Scale

Ring 13

Motion 14

Driving Motion 15

Lifting Motion 16

Foot at the Correct Height 17

Dog 18

Bearing

Bar at

Thread

Lever

Bracket

Hook

the

Beltinthe

Case

Opener

Case

Opener

Valve

Control

Release

Motion

Play

Winder

Lubrication

Pointers

Correct

Oil

Pulley

Height . 21

Gear

Case

Eccentric

Retainer

Ring 26

Slack

Thread Regulator . . 30

; . 23

4

6

11 11

19 20

22

24

25

27

28 29

29

31

32 33

34

35

C

PMFF

f

Nr. 296-12-12

853

eng!.

P 269

PrintedinGermany

Pfaff 438 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual