Pfaff 918 User manual

INSTRUCTION MANUAL
296-12-18 997/002
Betriebsanleitung engl. 06.12
This instruction manual applies to machines
from the following serial numbers onwards:
# 2 671 899
918
918 U
938
938 U

The reprinting, copying or translation of PFAFF Instruction Manuals, whether in whole or
in part, is only permitted with our previous authorization and with written reference to the
source.
PFAFF Industriesysteme
und Maschinen AG
Hans-Geiger-Str. 12 - IG Nord
D-67661 Kaiserslautern
This Instruction Manual is valid for all models and subclasses listed in the
chapter "Specifications".
The adjustment manual for the machines can be downloaded free of
charge from the internet address
www.pfaff-industrial.com/pfaff/de/service/downloads
As an alternative to the internet download the adjustment manual can also be
ordered in book form under part no. 296-12-18 998/002.

Index
Contents ..................................................................................Page
1Safety .................................................................................................................................... 5
1.01 Directives...............................................................................................................................5
1.02 General notes on safety......................................................................................................... 5
1.03 Safety symbols ...................................................................................................................... 6
1.04 Important points for the user................................................................................................. 6
1.05 Operating and specialist personnel........................................................................................ 7
1.05.01 Operating personnel .............................................................................................................. 7
1.05.02 Specialist personnel............................................................................................................... 7
1.06 Danger warnings.................................................................................................................... 8
2Proper use............................................................................................................................. 9
3Specifications ..................................................................................................................... 10
3.01 PFAFF 918, 938.................................................................................................................... 10
3.02 PFAFF 918 U, 938 U ............................................................................................................ 11
4Disposal of Machine .......................................................................................................... 12
5Transportation, packing and storage ................................................................................ 13
5.01 Transportation to customer‘s premises ............................................................................... 13
5.02 Transportation inside the customer‘s premises................................................................... 13
5.03 Disposal of packing materials ..............................................................................................13
5.04 Storage ................................................................................................................................ 13
6Explanation of symbols..................................................................................................... 14
7Controls .............................................................................................................................. 15
7.01 Main switch ......................................................................................................................... 15
7.02 Keys on the machine head (only on machines with flange motor)....................................... 15
7.03 Adjustment lever for zigzag stitch and needle position........................................................ 16
7.04 Reverse-feed key / Stitch length adjustment wheel............................................................ 16
7.05 Adjustment wheel for multi-stitch and zigzag stitch (only on the PFAFF 918 U and 938 U).... 17
7.06 Lever for raising presser foot ............................................................................................... 17
7.07 Pedal .................................................................................................................................... 18
7.08 Adjustment lever of the underedge trimmer -771/05 .......................................................... 18
7.09 Control panel........................................................................................................................ 18
8Installation and commissioning ....................................................................................... 19
8.01 Installation............................................................................................................................ 19
8.01.01 Adjusting the table-top height.............................................................................................. 19
8.01.02 Mounting the upper V-belt guard / Fitting the machine cover .............................................. 20

Index
Contents ..................................................................................Page
8.01.03 Fitting the reel stand ............................................................................................................ 20
8.01.04 Fitting the flange motor ....................................................................................................... 21
8.01.05 Fit the belt guard of the flange-motor.................................................................................. 21
8.01.06 Fitting the tilt lock................................................................................................................. 22
8.01.07 Connecting the plug-in connections and earth cables ......................................................... 22
8.02 Commissioning .................................................................................................................... 23
8.03 Switching the machine on/off ..............................................................................................24
8.04 Basic position of the machine drive unit
8.05 Mounting/connecting the start inhibitor............................................................................... 25
9Preparation ........................................................................................................................ 26
9.01 Inserting the needle............................................................................................................. 26
9.02 Winding the bobbin thread, adjusting the thread tension.................................................... 27
9.03 Removing / Inserting the bobbin case ................................................................................. 28
9.04 Threading the bobbin case, adjusting the thread tension .................................................... 28
9.04.01 PFAFF 938 and 938 U without thread trimmer .................................................................... 28
9.04.02 PFAFF 938 and 938 U with thread trimmer ........................................................................ 29
9.04.03 PFAFF 918 and 918 U .......................................................................................................... 29
9.05 Threading the needle thread / Adjusting the needle thread tension .................................... 30
9.06 Setting the zigzag stitch and the stitch position................................................................... 31
9.07 Adjusting the stitch length ................................................................................................... 31
9.08 Adjusting the multi-stitch or the zigzag stitch
(only on the 918 U and 938 U with flange motor)................................................................ 32
9.08.01 Changing from zigzag stitch to multi-stitch .......................................................................... 32
9.08.02 Changing from multi-stitch to zigzag stitch .......................................................................... 32
9.09 Adjusting the multi-stitch or the zigzag stitch
(on the 918 U and 938 U with an external motor).....................................................................33
9.09.01 Changing from zigzag stitch to multi-stitch .......................................................................... 33
9.09.02 Changing from multi-stitch to zigzag stitch .......................................................................... 33
10 Care and maintenance....................................................................................................... 34
10.01 Servicing and maintenance intervals ................................................................................... 34
10.02 Cleaning the machine .......................................................................................................... 34
10.03 Lubricating the hook ............................................................................................................ 35
10.04 Oiling the zigzag drive.......................................................................................................... 36
10.05 Checking/adjusting the air pressure .................................................................................... 37
10.06 Cleaning the air filter of the air-filter / lubricator .................................................................. 37
11 Wearing parts ..................................................................................................................... 38

5
Safety
1 Safety
1.01 Directives
The machine has been constructed in accordance with the requirements listed in the
EC Declaration of Conformity and the Declaration of Incorporation.
In addition to this Instruction Manual, also observe all generally accepted, statutory and
other regulations and legal requirements and all valid environmental protection regulations!
The regionally valid regulations of the social insurance society for occupational accidents or
other supervisory organizations are to be strictly adhered to!
1.02 General notes on safety
●This machine may only be operated by adequately trained operators and only after having
completely read and understood the Instruction Manual!
●All Notes on Safety and Instruction Manuals of the motor manufacturer are to be read be-
fore operating the machine!
●The danger and safety instructions on the machine itself are to be followed!
●This machine may only be used for the purpose for which it is intended and may not be
operated without its safety devices. All safety regulations relevant to its operation are to
be adhered to.
●When exchanging sewing tools (e.g. needle, roller presser, needle plate and bobbin),
when threading the machine, when leaving the machine unattended and during mainte-
nance work, the machine is to be separated from the power supply by switching off the
On/Off switch or by removing the plug from the mains!
●Everyday maintenance work is only to be carried out by appropriately trained personnel!
●Repairs and special maintenance work may only be carried out by qualified service staff
or appropriately trained personnel!
●Work on electrical equipment may only be carried out by appropriately trained personnel!
●Work is not permitted on parts and equipment which are connected to the power supply!
The only exceptions to this rule are found in the regulations EN 50110.
●Modifications and alterations to the machine may only be carried out under observance
of all the relevant safety regulations!
●Only spare parts which have been approved by us are to be used for repairs! We express-
ly point out that any replacement parts or accessories which are not supplied by us have
not been tested and approved by us. The installation and/or use of any such products can
lead to negative changes in the structural characteristics of the machine. We are not liable
for any damage which may be caused by non-original parts.

6
Safety
I
1.04 Important points for the user
●This Instruction Manual is an integral part of the machine and must be available to the
operating personnel at all times.
●The Instruction Manual must be read before operating the machine for the first time.
●The operating and specialist personnel is to be instructed as to the safety equipment of
the machine and regarding safe work methods.
●It is the duty of the user to only operate the machine in perfect running order.
●It is the obligation of the user to ensure that none of the safety mechanisms are removed
or deactivated.
●It is the obligation of the user to ensure that only authorized persons operate and work
on the machine.
Further information can be obtained from your PFAFF agent.
1.03 Safety symbols
Danger!
Points to be observed.
Danger of injury for operating and specialist personnel!
Caution
Do not operate without finger guard and safety devices.
Before threading, changing bobbin and needle, cleaning
etc. switch off main switch.

7
Safety
1.05 Operating and specialist personnel
1.05.01 Operating personnel
Operating personnel are persons responsible for the equipping, operating and cleaning of
the machine as well as for taking care of problems arising in the sewing area.
The operating personnel is required to observe the following points and must:
●always observe the Notes on Safety in the Instruction Manual!
●never use any working methods which could adversely affect the safety of the machine!
●not wear loose-fitting clothing or jewelery such as chains or rings!
●also ensure that only authorized persons have access to the potentially dangerous area
around the machine!
●always immediately report to the person responsible any changes in the machine which
may limit its safety!
1.05.02 Specialist personnel
Specialist personnel are persons with a specialist education in the fields of electrics, electro-
nics and mechanics. They are responsible for the lubrication, maintenance, repair and adjust-
ment of the machine.
The specialist personnel is obliged to observe the following points and must:
●always observe the Notes on Safety in the Instruction Manual!
●switch off the On/Off switch before carrying out adjustments or repairs, and ensure that
it cannot be switched on again unintentionally!
●wait until the luminous diode on the control box is no longer blinking or on before begin-
ning adjustment or repair work.
●never work on parts which are still connected to the power supply! Exceptions are ex-
plained in the regulations EN 50110.
●replace the protective coverings and close the electrical control box after all repairs or
maintenance work!

8
Safety
1.06 Danger warnings
A working area of 1mmust be kept free both in front of and behind the machi-
ne, so that easy access is possible at all times.
Never put your hands or fingers in the sewing area during sewing!
Danger of injury by the needle!
While setting or adjusting the machine do not leave any objects on the table nor
in the needle plate area! Objects may be trapped or flung out of the machine!
Fig. 1 - 01
2
1
4
3
5
6
Do not operate the machine without the take-up lever guard 1!
Danger of injury through the movement of the take-up lever.
Do not operate the machine without finger guard 2!
Danger of injury from the needle!
Do not operate machines with flange motor without start inhibitor 3!
Danger of injury if the machine is started accidentally!
When using an external motor do not operate the machine without belt guard 4
and 5! Danger of injury from the drive belts!
Do not operate the machine without tilt lock 6!
Danger of crushing between sewing head and table top!

Proper use
9
2 Proper use
The PFAFF 918 is a high-speed zigzag sewing machine with bottom feed and large hook.
The PFAFF 918 U is a high-speed zigzag sewing machine with bottom feed, a large hook and
mechanical shift from zigzag to 3-stitch zigzag.
The PFAFF 938 is a high-speed zigzag sewing machine with bottom feed.
The PFAFF 938 U is a high-speed zigzag sewing machine with bottom feed and mechanical
shift from zigzag to 3-stitch zigzag.
The machines are used for producing zigzag lockstitch seams in the clothing and linen industry
Any and all uses of this machine which have not been approved of by the
manufacturer are considered to be inappropriate! The manufacturer cannot be
held liable for any damage caused by the inappropriate use of the machine!
The appropriate use of the machine includes the observance of all operational,
adjustment, maintenance and repair measures required by the manufacturer!

10
Specifications
3 Specifications
3.01 PFAFF 918, 938 ▲
Stitch type:.............................................................................................. 304 (zigzag lockstitch)
Needle system:.................................................................................................................... 438
Needle size in 1/100 mm:
Model A: ......................................................................................................................... 60 - 70
Model B: ....................................................................................................................... 80 - 100
Presser foot clearance: .....................................................................................................7 mm
Clearance width: ...........................................................................................................260 mm
Clearance height: ..........................................................................................................130 mm
Bedplate dimensions: ......................................................................................... 476 x 177 mm
Sewing head dimensions:
Length:.................................................................................................................... ca. 550 mm
Width: ..................................................................................................................... ca. 180 mm
Height (above table): ............................................................................................... ca. 300 mm
Max. stitch length
PFAFF 918-6/01: .............................................................................................................4,5 mm
PFAFF 938-6/01; -6/27:...................................................................................................2,5 mm
Max. speed
PFAFF 918:.......................................................................................................... 5000 Sti/min ◆
PFAFF 938-6/01; -771/05-6/27:............................................................................ 5500 Sti/min ◆
PFAFF 938-34/01 R: ............................................................................................ 6000 Sti/min ◆
Max. stitch with
PFAFF 918:................................................................................................................... 10,0 mm
PFAFF 938-6/01:.............................................................................................................6,0 mm
PFAFF 938-771/05-6/27:.................................................................................................3,0 mm
PFAFF 938-34/01 R: .......................................................................................................4,5 mm
Connection data:
Operating voltage: ................................................................................ 230 V ± 10%, 50/60 Hz
Motor data: .................................................................... See instruction manual for the motor
Noise data:
Noise emission level at workplace with a sewing speed of 4000 spm: ...........LpA < 80 dB(A) ■
(Noise measurement in accordance with DIN 45 635-48-A-1, ISO 11204, ISO 3744, ISO 4871)
Net weight of sewing head:.........................................................................................ca. 46 kg
Gross weight of sewing head: .....................................................................................ca. 54 kg
▲Subject to alterations
◆Depending on the stitch length, the maximum speed is reduced automatically within the
max. pre-set value.
■KpA = 2.5 dB

11
Specifications
3.02 PFAFF 918 U, 938 U ▲
Stitch type:.............................................................................................. 304 (zigzag lockstitch)
Needle system:.................................................................................................................... 438
Needle size in 1/100 mm:
Model A: ......................................................................................................................... 60 - 70
Model B: ....................................................................................................................... 80 - 100
Presser foot clearance: .....................................................................................................7 mm
Clearance width: ...........................................................................................................260 mm
Clearance height: ..........................................................................................................130 mm
Bedplate dimensions: ......................................................................................... 476 x 177 mm
Sewing head dimensions:
Length:.................................................................................................................... ca. 550 mm
Width: ..................................................................................................................... ca. 180 mm
Height (above table): ............................................................................................... ca. 300 mm
Max. stitch length: .........................................................................................................2,5 mm
Max. stitch with
PFAFF 918 U: ............................................................................................................... 10,0 mm
PFAFF 938 U: .................................................................................................................6,0 mm
Max. speed:
With 33 mm needle bar stroke: .............................................................................. 4500 spm ◆
Connection data:
Operating voltage: ................................................................................ 230 V ± 10%, 50/60 Hz
Motor data: .................................................................... See instruction manual for the motor
Noise data:
Noise emission level at workplace with a sewing speed of 3600 spm: ........LpA < 78,5 dB(A) ■
(Noise measurement in accordance with DIN 45 635-48-A-1, ISO 11204, ISO 3744, ISO 4871)
Net weight of sewing head:.........................................................................................ca. 46 kg
Gross weight of sewing head: .....................................................................................ca. 54 kg
▲Subject to alterations
◆Depending on the stitch length, the maximum speed is reduced automatically within the
max. pre-set value.
■KpA = 2.5 dB

Disposal of Machine
12
4 Disposal of Machine
●Proper disposal of the machine is the responsibility of the customer.
●The materials used for the machine are steel, aluminium, brass and various plastic
materials. The electrical equipment comprises plastic materials and copper.
●The machine is to be disposed of according to the locally valid pollution control regula-ti-
ons; if necessary, a specialist ist to be commissioned.
Care must be taken that parts soiled with lubricants are disposed of separately
according to the locally valid pollution control regulations!

Transportation, packing and storage
13
5 Transportation, packing and storage
5.01 Transportation to customer‘s premises
The machines are delivered completely packed.
5.02 Transportation inside the customer‘s premises
The manufacturer cannot be made liable for transportation inside the customer‘s premises
nor to other operating locations. It must be ensured that the machines are only transported
in an upright position.
5.03 Disposal of packing materials
The packing materials of this machine comprise paper, cardboard and VCE fibre. Proper dis-
posal of the packing material is the responsibility of the customer.
5.04 Storage
If the machine is not in use, it can be stored as it is for a period of up to six months, but It
should be protected against dust and moisture.
If the machine is stored for longer periods, the individual parts, especially the surfaces of
moving parts, must be protected against corrosion, e.g. by a film of oil.

Explanation of symbols
14
6 Explanation of symbols
In this instruction manual, work to be carried out or important information is accentuated by
symbols. These symbols have the following meanings:
Note, information
Cleaning, care
Lubrication
Maintenance, repairs, adjustment, service work
(only to be carried out by technical staff)

15
Controls
7.02 Keys on the machine head (only on machines with flange motor)
●As long as key 1is pressed during sew-
ing, the machine sews in reverse.
●Keys 2and 3can be allocated with cor-
responding parameter settings, see the
Motor Instruction Manual.
7 Controls
7.01 Main switch
Fig. 7 - 01
1
●The machine is switched on or off by tur-
ning the main switch 1.
Fig. 7 - 02
2
1
3

16
Controls
Fig. 7 - 04
Fig. 7 - 03
7.03 Adjustment lever for zigzag stitch and needle position
●The zigzag stitch adjustment lever 1is
used for adjusting the width of the zig-
zag stitch.
●To change the position of the adjustment
lever, the locking lever 2must be pressed
against the adjustment lever 1.
The current zigzag-stitch width
can be seen on scale 3.
●By turning the needle-position adjust-
ment lever 4the required needle position
can be set.
L= needle-position left
M= needle-position center
R= needle-position right
1
2
R
3
L
4
M
7.04 Reverse-feed key / Stitch length adjustment wheel
●The machine sews in reverse as long as
the reverse-feed key 1is pressed.
●The stitch length can be adjusted by
turning the stitch length adjustment
wheel 2.
●The stitch length setting can be read on
scale 3.
12
3

17
Controls
Fig. 7 - 05
7.06 Lever for raising presser foot
●The presser foot is raised by turning
lever 1.
1
7.05 Adjustment wheel for multi-stitch and zigzag stitch
(only on the PFAFF 918 U and 938 U)
Before sewing begins, make
sure that adjustment wheel 1is
locked in position! Only switch
over when the machine is at a
standstill! Danger of machine
damage!
●It is possible to switch between multi
stitch and zigzag stitch with adjustment
wheel 1, see Chapter 9.10 Adjusting the
multi- or zigzag stitch.
Fig. 7 - 06
1

18
Controls
0
1
2
3
4
7.08 Adjustment lever of the underedge trimmer -771/05
●By pulling and turning lever 1towards "+",
the underedge trimmer is switched on
and the knife stroke set.
Do not touch the knife while it
is running!
Danger of injury from the mo-
ving knife.
Fig. 7 - 08
1
7.09 Control panel
The description can be found in the separate instruction manual for the motor.
7.07 Pedal
0= Neutral position
+1= Sewing
-1= Raise presser foot
(on machines with -910/..)
-2= Trim thread
(on machines with -900/..)
Fig. 7 - 07
-1
+1
0
-2

19
Installation and commissioning
Fig. 8 - 01
2
11
●Loosen screws 1and 2and set the desired table-top height
●Tighten screws 1well.
●Adjust the position of the pedal so that you can operate it comfortably and tighten screw 2.
8 Installation and commissioning
The machine must only be mounted and commissioned by qualified personnel!
All relevant safety regulations are to be observed!
If the machine is delivered without a table, it must be ensured that the frame
and the table top which you intend to use can hold the weight of the machine
and the motor. It must be ensured that the supporting structure is sufficiently
sturdy, including during all sewing operations.
8.01 Installation
The site where the machine is installed must be provided with suitable connections for the
electric current, see Chapter 3Specifications.
It must also be ensured that the standing surface of the machine site is firm and horizontal,
and that sufficient lighting is provided.
The method of packaging used requires that the table top be lowered for trans-
port. The following is a description of how to adjust the height of the table top.
8.01.01 Adjusting the table-top height

20
Installation and commissioning
●Slide the left and right halves of the V-belt
guard into place with the slots behind the
heads of screws 1and 2.
●Screw screw 3with distance bush 4into
threaded hole 5.
●Align the V-belt guard, taking care that
clip 6is behind slot 7and in front of di-
stance bush 4.
●Tighten screws 1and 2(through holes 8
and 9) and screw 3.
●When using an external motor, the motor
cover must also be fitted as described by
the motor manufacturer.
Fig. 8 - 02
1
2
8.01.02 Mounting the upper V-belt guard / Fitting the machine cover
43
56
9
7
8
8.01.03 Fitting the reel stand
●Fit the reel stand as shown in Fig. 8- 03.
●Afterwards insert the stand in the hole in
the table top and secure it with the nuts
provided.
Fig. 8 -03