Pfaff Automatic 260 User manual

-
260+ 360
•
erv1ce
anual
Functions of Assemblies · Adjustment Procedures
Sewing-off · Trouble Shooting · Electrical Equipment

SERVICE
MANUAL
for Pfaff Sewing Machines 260 and 360
with built-in automatic
embroidery mechanism
Functions
of Assemblies
Electrical Equipment
Adjustment Procedures
Sewing-off
Trouble Shooting
G·M ·PFAFF AG · KARLSRUHE-DURLACH BRANCH

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Foreword
This profusely illustrated Service Manual for Pfaff 260 (360)- 261 sewing ma-
chines is a
valuable source of technical information which is primarily in-
tended
for Pfaff dealers and their service personnel.
It goes i nto greater detail and, thus, complements the instruction book which
accompanies each machine. The
nomenclature used in the pertinent spore
ports
catalogue has also been used throughout this book. Numerous photo-
grap hs and draw ings are interspersed in the text in order to give users a
good i deo of the assembli es being discussed.
Beg i nning with a general description of the workings of a sewing machine,
the
monual proceeds to discuss how the zigzag and automatic mechani sms
function. The adjustment procedures wh i ch follow ore intended for those of
our dealers who hove to remedy sewing trou ,bles that may occur occasionally.
The prime object of this manual is , howeve r, to import additional technical
knowledge to all who ore connected with the sale and repo ir of the Pfaff
260 (360)- 261 and to enable them to render satisfactory service.
G. M. PFAFF AG

CONTENTS
Foreword
How a Sewing Machine Functions .
TheNeedle . .
The Sewing
Hook . . . .
St itch Formation and Feed Motion
The Take-Up lever .
The
Feed Dog .
Dropping the Feed Dog
Stitch length Regulation
Reverse
Sewing . . . .
Regulating
the Thread Tension .
The Bobbin
Thread Tension .
Regulat i ng the Thread Tension .
The
Needle Thread Tension
W i
nding the Bobbin .
Inserti ng the Bobbin Case
Needle and Thread Chart
Threading the Needle .
Zigzag Sewing .
The
Zigzag Mechan i sm .
The Fi nge r-Tip Contro l . .
Changing the Needle Positi on . . . .
Mechan i cal Principle of Automatic Machines .
Mechan i cal Principle of the Pfaff -261 Automatic
The Electrical Equipment . . . . .
Suppress i on of Radio and TV Interference .
The
lighting System
The Electric Drive .
Multi-Voltage Motors for Pfaff 260 and 360 Machines
Maintenance
Storing Sewing Heads and Cabinets
Checking Cabinets and Stands . .
Attaching
the Bedplate Extension .
Mount ing the Sewing Head
Removing the Rust-Preventative Fluid
Cleaning and O iling
Removing the Top Cover
Cleaning the Feed Dog and the Sewing Hook
Removi ng and Replacing t he Face Cover
The Needle Threader
Stitching off the Machine
Checking t he Automa~ic Mechanism
Regul
at ing the Pressure on the Materia l
Threading the Machine for Two-Need le Work
Preparing the Machine for Two-Needle Decorative Sewing
Rules Your Cust
omers Should Know
Adjustment Procedures .
The Feed Eccentric .
Page
7
7
8
11
12
12
13
13
14
15
15
15
16
17
17
18
19
20
20
21
21
22
23
29
31
32
33
35
36
36
37
37
37
38
38
38
39
39
42
42
43
43
44
44
45
46
46

Page
The Upper Driving Belt Sprocket 46
The
Needle Vibrating Eccentric Bevel Gear . 47
The Driving Eccentric
for the Automatic Mechanism 48
Timing the Sewi:ng Hook 48
Pfaff 260- Needle Bar Rise 49
The
Upper Driving Belt Sprocket 50
Pfaff 360- Needle Bar Rise . 51
Exchanging the Sewing Hook in the Pfaff 360 52
The Position
Finger Brocket . . 52
Setting the Needle Bar at Correct Height . 53
Adjusting
the Feed Dog in the Feed Slot . . 53
Setting
the Presser Bar and the Feed Dog at Correct Height 55
Dismantling, Replacing
and Adjusting tne Stitch length Control 56
Adjusting
the Bobbin Winder . 57
Setting the Needle Threader 58
Changing the Thread Check Spring 60
Changing the Cord Belt . . . . . . . . . 61
Assembling and Adjusting the Zigzag Regulator Mechanism 63
The Zigzag Regulator Mechanism . 64
Stripping the Automatic Mechanism 64
Dismantling the Stitch Width Control 64
The Stitch Width Regulating Mechanism in the Machine Arm 64
The Stitch Width Control 65
Adjusting the Stitch Width Control . 66
Rough Adjustment
of Zigzag Stitch . 67
Fine Adjustment of Zigzag Stitch 67
Zeroing the Needle for StraightStitching 67
Adjusting the Needle Position . . 68
Centering
the Needle in the Needle Plate Slot 69
Converting a Pfaff
260 (360) into a Pfaff 260-261 (360-261) 71
Installing the Automatic Mechanism 71
Mounting the Engaging levers . 71
Essential Parts of the Pfaff (-261) Automatic 73
Mounting the Pressure Spring Assembly 75
Adjusting
the Engaging levers . 75
Replacing
the Top Cover . . . . . . . . . 76
Checking the Needle Position in Relation to the Needle Plate Slot 76
Testing the Performance of the Automatic Mechanism . 77
Checking the Operation of the Engaging levers 77
Eliminating Troubles in Automatic Sewing . 77
Installing a PE 260 or 261 Motor into the Pfaff 260 (-261) 79
Changing the Motor Belt 81
Trouble Shooting . . . . . . . . 81
Dismantling and Reassembling the Pfaff Hook . 84
Works
of the Pfaff 260-261 . • 85
TheTwo-Position Presser
Bar lifter . 86
The PfaffTool
Kit . . 86
Abridged Adjustment Procedure for the Zigzag Regulator Mechanism of
Pfaff 260 (360) Machines 87

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How a Sewing Mact.ine Functions
Household sewing machines all make the conventional lockstitch. This type of
stitch consists of on upper (needle) and a lower (bobbin) thread locked together·
in the material being stitched. The lock of threads is pulled to the middle of
the fabric so that the seam has the same appearance top and bottom.
Every sewing machine designed to produce this type
of stitch must hove the
following component ports and assemblies:
1. a needle
2. a sewing hook, complete with bobbin case and bobbin
(typical of any lockstitch sewing machine)
3. a take-up lever
. 4. an upper and a lower tension mechanism
5. a feed dog
6. Stitch forming and feeding mechanisms
7. a bobbin winder.
The Needle
In contrast to the hand sewing needle, the machine sewing needle has the eye
near its tip. It penetrates the material at every stitch, carrying the thread
down through the hole it has mode in the fabric. As it rises after reaching
the lowest point
of its stroke, the thread bulges out on the short-groove side
of the needle to form a loop above its eye. This loop is entered ot the correct
time by the point
of the shuttle or sewing hook (figs. 1 & 2).
l 1
Fig. 1 Fig. 2
Sewing machine needles are available in many different varieties and sizes,
and are classified into several groups, or systems.
7

Fig . 3
Needle System 130 R
(Needle size, e. g.
No . 80, 90 or 1()()_
given in hundredths of
millimeters)
F = Flat side of shank
L =Length
of needle
St= Needle size (shaft diameter)
I = long groove
k = Short groove
H =
Scarf (cleoronce cut)
S = Point
0= Eye
Fig. 4 Fig. 5 Fig. 6
Pfaff domestic sewing machines normally use System 130 R needles with flat
shank
and scarf (Fig. 4). System 130 B round-shank needles are used for cord-
ing and two-needle fancy stitching. Make sure you use only "ORIGINAL
PFAFF " needles (see a ls o page 81 ).
Needle sizes are determined by the shaft diameter (St in Fig. 5) and ore
measured in hundredths of millimeters. A No. 100 needle, for example, has a
blade diameter of
100
/Joo, or one, millimeter.
Opposite the flat side of the shank, a long groove extends all the way down
to the needle eye. On Pfaff zigzag and automatic sewing machines, this
groove must face toward the operator always. The scarf, or clearance cut,
marked H
in Fig. 4 then faces toward the sewing hook.
The correct relationship between needle
and thread size may be seen from the
Needle and Thread Chart on page 18.
The Sewing Hook
The functions of the sewing hook are (1) to enter with its point the needle
thread loop which forms at the needle eye as the needle ascends, (2) to en-
large this loop, and (3) to pass it around the stationary bobbin case (Fig. 6).
'
There are different types of loop takers, the most popular of which ore:
a. Shuttles that move in a race and are driven by a shuttle driver, such as the
central-bobbin, or oscillating, shuttle d·epicted in Fig. 7, and
b. Sewing hooks which ore carried on a shaft and revolve freely.
8

fig . 7 Oscillating shuttle Fig. 8 Rotary hook with floating bobbin case
1 = Shuttle race (cut -away view) 4 = Bobbin case 1 = R otary hook 2 = Bobbin case
3 = Shuttle 8 = Shuttle driver 3 = Retainer
Fig. 9 Rotary hook with
stationary
11 bobbin case
1 = Hook gib
2 = Hook point
3 = Hook shaft
4 = Bobb<n case bose
5 = Sewing hook
8 = Bobbtn
case cop
9 = Center stud
10 = Bobbin case latch
11 = Bobbin case position fi nger
brocket
12 = Bobbin case position finger
The rotary sewing hooks mentioned under b. above are incorporat ed in
modern sewing machines in two varieties, known as:
a. The rotary hook with floating bobbin case. Th is type of sewing hook, as
the name
implies, features a bobbin case which floats in the hook bowl
and is kept from falling out by a retainer (Fig. 8).
b. The rotary hook with stationary bobbin case. The bobbin case of this type
hook features a ring-shaped flange which runs in an annular groove, or
raceway, cut into the hook bowl. It is held in place by a hook gib so that
it
cannot fall out while sewing. The bobbin case cap is pushed on the
center stud in the bobbin case base (Fig. 9) .
e c h b g
f i gs . 10- 14
9

The loop taker used in Pfaff 260 (360)- 261 domestic sewing machines is the
type
of sewing hook described under b. above. It is a sewing hook of Pfaff's
own design which
is rated as jam-proof. Mounted on a horizontal shaft, this
new Pfaff hook (Fig.
15) is set transverse to the direction of feed and moves
counter-clockwise, making two revolutions for each stitch. In other words, a
stitch
is formed only at every other revolution of the sewing hook, which is a
favorable ratio for the take-up lever motion.
Fig . 15 Pfaff rotary hook
a = Position slot
b = Bobbin case bose
c = Bobb in
d = Bobbin case latch
e = Bobbin case cop
f =Sewing hook
g = Hook point
h = Hook thread
guard
Fig. 16 Works of the Pfaff 260 · 261
10

8 Fig. 17
Text see page 12
--- 9
23
18
Stitdt Formation and F .. d Motion
Fig. 18
Text see page 12
t
19

Stitch Formation
1 Hinge stud
2 Take-up lever li
nk
3 Toke-up crank
4 Motion pattern
of the toke-up lever
5
Link toke-up lever
6 Needle bar crank
7 Needle
bar connecting link
8 Needle bar connecting stud
9 Needle
bar
10 Needle set screw
11 Needle holder
12 Needle
13 Hook point
14 Hook thread guard
15 Hook shaft
16 Hook drive shaft helical
gears
17 Hook drive shaft
18 Rotary hook
19 Arm shaft
20 Driving belt sprocket, upper
21 Driving belt (Synchroflex)
22 Driving belt sprocket, lower
23 Driving belt (cord)
Note: The needle plate has been omitted in
order to give o better view.
The Take-Up Lever
Feed Motion
1 Pressure regulating screw
2 Presser
bar guide collar
3 Presser bar lifting brocket
4 Presser bar
5 Thread cutter
6 Sewing foot
7 Center stud
8 Feed motion
diagram
9 Feed dog
10 Feed bar
11 Feed lifting shaft crank, front
12 Center stud
13 Roller
14 Feed lifting shaft
15 Center stud
16 Feed rock shaft
17 Feed rock shaft crank
18 Center stud
19 Feed lifting shalt crank, rear
20 Finger-tip control H
21 Stitch length dial G
22 Feed regulator
23 Feed eccentric
24 Arm shaft
25 Feed lifting connection
26 Feed forked connection
The function of the take - up is to provide the correct amount of thread
required to enlarge the loop, and to draw back the excess thread after the loop
has passed around the bobbin case. As it approaches the highest point of its
stroke,
the take-up lever, ass isted by the advancing feed dog, pulls the stitch
tight and at the same time draws additional thread through the upper te nsion
for the next stitch.
All Pfaff domestic sewing machines are equipped with the long-valued link
take-up (Fig. 17).
fig. 19 Feed dog in operative position Fig. 20 Sewing forward and reverse
The Feed Dog
The principal function of the feed dog is to move the material forward or
backward in accordance with the stitch length set. Rev erse feeding is used to
backtack the end of a seam.
12

Depending on the type of work the machine is intended to perform, it can be
suppli ed not only with an ordinary feed dog, but also with feed dogs featur-
ing a coarse or flne tooth cut.
Dropping the Feed Dog
The feed dog is dropped for darning, embroidering and button sewing. To
lower the feed
dog (F ig. 21), turn drop feed control V clockwise (Fig. 22). The
fabric will cease feeding. When the control is flicked back to its normal posi-
tion, the feed dog wi ll show a full too th above the needle plate as it advances
(Fig. 1 9), thus automatically resuming the feeding of the fabric.
fig. 22 Drop feed control
Fig. 21 Feed dog lowered
Stitch Length Regulation
The stitch length di al (F ig. 23) has two graduated sections of the some size,
one from 0 to l, and the other from l to 4. This feature greatly facilitates the
fine regulation of the sti1ch length for satin stitching. The dial can also be
set to any intermedi ate length between the graduation marks.
Figs. 23 & 24 Stitch length dial G with finger-tip control H
13

Reverse Sewing
To backtack the beginning or end of a seam, the machine is briefly switched
to reverse stitching by depressing spring-loaded finger-tip control H. The
machine can be switched to backward sewing, regardless of the stitch length
set.
When the control is released, the machine resumes forward sewing auto-
matically. If a longer stretch of seam is to be sewn in reverse, turn the stitch
length
dial counter-clockwise past 0, setting it on one of the two unnumbered
graduation mar ks (Fig. 24} .
First mark
Second mark
I.
Fi g. 25
s
short reverse stit ch es,
long reverse stitches.
II.
Fig. 26
Fig.
2S Bobbin t hread tension S
14
Ill.
Fig. 27
Fig. 29 Needle thread tension M

The Thread Tens ion
Both threads must be under proper tension to ensure a correct setting of
stitches. Depending on the type of fabric being sewn and the thread size
used, both tensions must
be balanced so that the lock of the needle ond bob-
bin threads occurs exact ly in the center of the mater ial. The correct amount
of tension
on the needle thread is set by the upper tensi on (tensi on discs) on the
fr
ont of the machi ne (Fig. 29), and
on the bobbin thread, by the lower tension (flat spring) on the bobbin
case (Fig. 28) .
The upper tension is so designed that all grades of tension, from loose to
tight, con be covered with one complete turn of the tensi on dial. Any desired
degree of tension con be set by the numbers indicated on the dial. This setting
can be quickly restored if the tension should hove been altered for some
special sewing job.
The needle thread tensi
on has a third tension disc for two-needle work so
that both threads are separated in the tension mechanism.
The Bobbin Thread Tension
To balance the tensions correctly, begin by setting the bobbin thread tensi on
at a medium grade. To this end, tighten the regulating screw until a notice-
able resistance has to be overcome when pulling the thread .
Determine the correct
bobbin thread tension by holding the thread end
between your fingers and letting the bobbin case hang freely. The tension
should
be strong enough to keep the bobbin case from being pulled down by
its own weight. However , as you jerk your hand slight ly, the bobbin case
should gradually slide down (Fig. 30) .
Regulating the Thread Tension
No screwdriver is required to adjust the bobbin thread tension on Pfaff 260
and 360 machines. Instead, the knurled screw on the bobbin case con be
turned with the thumb tip, as follows:
Turn it left for a
looser tension,
and right, for a tighter tension.
Do not turn the knurled screw too for out so that it wi ll not fall out and get
lost.
15

The Needle Thread Tension
Once the bobbin thread tension has been set correctly, the final stitd1 ap-
pearance can be regulated by the upper tension dial.
Sketch Ill (Fig. 27) depicts the perfect stitch. Both threads are interlaced in the
center of the material.
In sketch I (Fig. 25), the threads interlock on the underside of the fabric.
Cause: Upper tension too loose or l ower tension too tight.
In sketch II (Fig. 26), the threads interlock on the surface of the fabric.
Cause:
Upper tension too tight or lower tension too loose.
In zigzag sewing, the lock of the thread should occur exactly at the zigs ana
zags of the seam (Fig. 32).
s
Fig. 30
Determining correct
bobbin th feod tension
16
Fig. 32 Zigzag seam
(tap and bottom)
Fig. 31 Bobbin winding

General Chedtup
Before the machine is delivered to the customer it must be given a thorough
checkup to ascertain that it will function properly. Unfortunately, all kinds
of
sewing trouble may be caused in transit.
Winding the Bobbin
To make the machine ready for sewing, wind No. 60 thread on the bobbin, at ·
the same time checking the correct working of the bobbin winder. Check to
see, in particular, that the bobbin is wound evenly and that the bobbin winder
stops automatically when the bobbin is full (see page 16).
Inserting the Bobbin Case
Insert o full bobbin into the bobbin case and check the tension on the bobbin
thread (see page 15).
Hoving ascertained that the tension is correct, check to see that the needle is
above the needle plate before you insert the bobbin case in the machine.
With
the thumb and forefinger of ·your left hand, lift bobbin case latch k and
turn the bobbin case until the slot marked with on arrow in Fig . 34 points up.
Then
place it on center stud s in the bobbin case base.
Release latch k and press aga inst the bobbin case until you hear it snap into
place. An improperly inserted bobbin case is op t to cause needle breakage.
In replacing the bobbin case make sure that the loose end of the bobbin
thread will not get jammed in the hook raceway.
Fig. 33 Engaging and disengaging the sewing
mechanism Fig.
34 Inserting the bobbin case
17

NEEDLE AND THREAD CHART
I I
Me rcerized Needle
Types of Fabri cs
Co tton
Si l l<
Si ze
I
Fin e Fabric s
80
I 0
s uch as georgette, chiffon, batiste,
to
to
60
000 70
voile, lawn, silk. I
100
twist
--
Lightweigh t Fabri cs
70
A&B
such as dress silks and cottons,
to
twist
80
sheer woolens, shirting, draperies.
80
I
Med ium Fabr ics
50
such as lightweight woolens, to
B&C
90
madras, muslin, brocades, heavy
70
twist
silks and rayon, gabardine.
---- -
Heavy Fabri cs
40
such as coating, denim, corduroy,
C&D
100
slipcover fabrics, bed lickings, to twist
lightweight canvas.
50
Ve ry Heavy Fa bric s I 24 E
90
such as heavy lickings, canvas,
to
twisl to
overcoating,
sai lcloth, upholstery.
40 110
I
------
Synthetics, Rayo n, Acetate I Determined by Determined
b) ·
including nylon, orion, docron, weight
of fabric thread size
plastics, etc.
40 to 50 60 to 80
18

Threading the Needle
Insert a new No . 80 needle and place a spool of No. 50 thread on the spool
pin. The bobbin thread should be
one size smaller than the needle thread.
Then thread the needle os shown
in Fig. 35 above.
The
appearance of the finished seam depends on the correct relationship
between needle, thread
and fabric. To select the proper needle and thread
sizes, therefore, consult the Needle
and Thread Chart on page 18.
Figs. 36 & 37 Changing the needle plate
19