Pfaff Industrial 918 U User manual

INSTRUCTION MANUAL
296-12-19 337/002
Instruction Manual engl. 06.18
918
918 U
938
938 U
This instruction manual applies to machines
from the serial number 8 300 001 and
software version 0435/006 onwards.

This instruction manual applies to all models and subclasses listed in chapter 3
Technical Data.
The adjustment manual for the machine can be downloaded at no charge
under www.pfaff-industrial.de/de/service-support/downloads/technical. As
an alternative to the Internet download, the adjustment manual can also be
ordered under order no. 296-12-19 338/001.
Reprinting, reproduction and/or translation of PFAFF instruction manuals (including parts
thereof) is only permitted with our prior agreement and citation of the source.
PFAFF Industriesysteme
und Maschinen GmbH
Hans-Geiger-Str. 12 - IG Nord
D-67661 Kaiserslautern

Table of Contents
Contents ..................................................................................Page
3
1Safety .................................................................................................................................... 5
1.01 Directives ............................................................................................................................... 5
1.02 General safety instructions .................................................................................................... 5
1.03 Safety symbols ...................................................................................................................... 6
1.04 Special points of attention for the owner-operator................................................................. 6
1.05 Operating personnel and technical staff ................................................................................ 7
1.05.01 Operating personnel .............................................................................................................. 7
1.05.02 Technical staff ........................................................................................................................ 7
1.06 Danger warnings.................................................................................................................... 8
2Proper Use............................................................................................................................ 9
3Technical Data s................................................................................................................ 10
3.01 PFAFF 918, 938.................................................................................................................... 10
3.02 PFAFF 918 U, 938 U s....................................................................................................... 11
4Disposal of the Machine .................................................................................................... 12
5Transport, Packaging and Storage.................................................................................... 13
5.01 Transport to the customer's premises................................................................................. 13
5.02 Transport within the customer's premises .......................................................................... 13
5.03 Disposal of the packaging materials .................................................................................... 13
5.04 Storage ................................................................................................................................ 13
6Work Symbols .................................................................................................................... 14
7Operating Controls ............................................................................................................ 15
7.01 Main switch ......................................................................................................................... 15
7.02 Keys on the machine head (only in machines with a flange motor) ..................................... 15
7.03 Adjusting levers for zigzag stitch and needle position.......................................................... 16
7.04 Reverse-feed key / stitch length adjusting wheel................................................................ 16
7.05 Adjusting wheel for multi-stitches and zigzag stitches
(only on the PFAFF 918 U and 938 U).................................................................................. 17
7.06 Lever to raise the sewing foot ............................................................................................. 17
7.07 Pedal .................................................................................................................................... 18
7.08 Adjusting lever for under-edge trimmer -771/05 .................................................................. 18
7.09 Control panel (only in machines with P40 CD)..................................................................... 18
8Set-up and Initial Start-up ................................................................................................. 19
8.01 Set-up .................................................................................................................................. 19
8.01.01 Setting the table height........................................................................................................ 19
8.01.02 Inserting the sewing machine into the stand....................................................................... 20
8.01.03 Assembling the flange motor............................................................................................... 21
8.01.04 Mounting the flange motor belt guard................................................................................. 21
8.01.05 Mounting the machine cover ............................................................................................... 22
8.01.06 Assembling the anti-tipping device ...................................................................................... 22

Table of Contents
Contents ..................................................................................Page
4
8.01.07 Mounting the start inhibitor ................................................................................................. 23
8.02 Connecting the plug-in connections and ground cable ........................................................ 24
8.03 Assembling the reel stand ................................................................................................... 25
8.04 Initial start-up ....................................................................................................................... 26
8.05 Switching the machine on / off ............................................................................................ 27
8.06 Machine drive home position............................................................................................... 27
9Set-up.................................................................................................................................. 28
9.01 Inserting the needle............................................................................................................. 28
9.02 Winding the bobbin thread / adjusting the bobbin thread tension ....................................... 29
9.03 Removing / inserting the bobbin case.................................................................................. 30
9.04 Inserting the bobbin case / adjusting the bobbin thread tension ......................................... 30
9.04.01 PFAFF 938 and 938 U without thread trimmer .................................................................... 30
9.04.02 PFAFF 938 and 938 U with thread trimmer ......................................................................... 31
9.04.03 PFAFF 918 and 918 U .......................................................................................................... 31
9.05 Threading the needle thread / adjusting the needle thread tension..................................... 32
9.06 Setting the zigzag stitch and needle position....................................................................... 33
9.07 Setting the stitch length....................................................................................................... 33
9.08 Setting multi-stitches and zigzag stitches
(on the 918 U and 938 U with a flange motor)..................................................................... 34
9.08.01 Change-over from zigzag stitch to multi-stitch ..................................................................... 34
9.08.02 Change-over from multi-stitch to zigzag stitch ..................................................................... 34
9.09 Setting multi-stitches and zigzag stitches
(on the 918 U and 938 U with an external motor).........................................................................35
9.09.01 Change-over from zigzag stitch to multi-stitch ..................................................................... 35
9.09.02 Change-over from multi-stitch to zigzag stitch ..................................................................... 35
10 Maintenance and Care....................................................................................................... 36
10.01 Maintenance intervals.......................................................................................................... 36
10.02 Cleaning the machine .......................................................................................................... 36
10.03 Oiling the hook..................................................................................................................... 37
10.04 Oiling the zigzag drive.......................................................................................................... 38
10.05 Checking / setting the air pressure ...................................................................................... 39
10.06 Emptying / cleaning the maintenance unit's water tank...................................................... 39
10.07 Parameter settings .............................................................................................................. 40
11 TableTop ............................................................................................................................. 41
11.01 Table top cutout ................................................................................................................... 41
11.02 Table top assembly .............................................................................................................. 42
12 Wearing Parts ..................................................................................................................... 43

Safety
5
1 Safety
1.01 Directives
The machine was built in compliance with the European regulations specified in the
declaration of conformity and declaration of incorporation.
As a supplement to this instruction manual, please also observe the generally applicable,
legal and other regulations and legislation – also in the country of use – and the valid
environmental protection regulations! Always comply with the locally applicable regulations
of the professional associations and other supervisory authorities!
1.02 General safety instructions
OThe machine may only be operated after you have become acquainted with the
associated instruction manual and only by operating personnel who have received
appropriate training!
OAlways read the safety instructions and the instruction manual of the motor manufacturer
before starting up the machine!
OAlways follow the hazard and safety instructions attached to the machine!
OThe machine may only be operated for its intended purpose and only with the associated
safety covers, while adhering to all the relevant safety requirements.
OThe machine must always be disconnected from the power supply by pressing the main
switch or pulling out the mains plug when sewing tools are replaced (such as the needle,
sewing foot, needle plate and bobbin) and when threading, leaving the workstation, or
performing maintenance!
OThe daily maintenance work may only be carried out by suitably qualified personnel!
ORepairs and special maintenance work may only be carried out by technical staff or
people with appropriate training!
OWork on electrical equipment may only be carried out by qualified technical staff!
OWork on parts and equipment under voltage is not permitted!
OExceptions are regulated by the EN 50110 standards.
OModifications and changes to the machine may only be made in compliance with all of
the relevant safety requirements!
OOnly the replacement parts approved by us for usage may be used for repairs! We warn
you expressly that spare parts and accessories that are not supplied by us are also not
tested and approved by us.
Fitting or using these products may therefore have negative effects on features which
depend on the machine design. We are not liable for any damage caused by the use of
non-Pfaff parts.

Safety
6
1.03 Safety symbols
Hazard point!
Special points of attention.
Risk of injury to operating personnel or technical staff!
Electric voltage!
Danger to operating personnel or technical staff
Danger of hands being crushed!
Danger to operating personnel or technical staff
Caution!
Do not operate without finger guard and safety covers!
Turn off the main switch before threading, changing the
bobbin or needle, cleaning, etc.!
1.04 Special points of attention for the owner-operator
OThis instruction manual is a part of the machine and must be made available to the
operating personnel at all times. The instruction manual must have been read before the
initial start-up.
OThe operating personnel and technical staff must be instructed about the machine’s
safety covers and about safe working methods.
OThe owner-operator may only operate the machine in a flawless condition.
OThe owner-operator must ensure that no safety covers are removed or disabled.
OThe owner-operator must ensure that only authorised persons work on the machine.
Additional information can be requested from the responsible sales centre.

Safety
7
1.05 Operating personnel and technical staff
1.05.01 Operating personnel
Operating personnel are persons responsible for equipping, operating and cleaning the
machine and for fault clearance in the sewing area.
The operating personnel are obligated to comply with the following points:
OThe safety instructions provided in the instruction manual must be followed for all work!
OAny work method jeopardising machine safety must be refrained from!
OTight-fitting clothing must be worn. The wearing of jewellery such as chains and rings is
prohibited!
OCare must be taken to ensure that no unauthorised persons are located in the machine’s
hazard zone!
OAny changes occurring on the machine which impair its safety must be reported to the
owner-operator immediately!
1.05.02 Technical staff
Technical staff are persons with technical training in electricity/electronics and mechanics.
They are responsible for lubricating, servicing, repairing and adjusting the machine.
The technical staff are obligated to comply with the following points:
OThe safety instructions provided in the instruction manual must be followed for all work!
OTurn off the main switch and secure it against reactivation before starting any adjustment
and repair work!
ONever work on live parts and equipment!
Exceptions are regulated by the EN 50110 standards.
OReattach the safety covers following repair and maintenance work!

Safety
8
1.06 Danger warnings
A work area of 1mmust be kept free in front of and behind the machine to en-
sure unobstructed access at all times.
Do not reach into the needle range during the sewing operation!
Risk of injury from the needle!
Do not allow any objects to be placed on the table during the adjustment work!
The objects could become jammed or be slung away!
Risk of injury from parts flying around!
Fig. 1 - 01
2
16
Do not operate the machine without the take-up lever guard 1!
Risk of injury due to the motion of the take-up lever!
Do not operate the machine without the finger guard 2!
Risk of injury from the needle!
Do not operate the machine without the anti-tipping device 3!
Risk of injury from crushing between the sewing head and the table top!
Do not operate the machine without the support 4! Risk of damage due to the
top-heavy sewing head!
Machine can tip over backwards when moving it!
Do not operate machines with an underfloor motor without the belt guard 5 and 6!
Risk of injury from the driving belt!
Do not operate machines with a flange motor without the start inhibitor 7!
Risk of injury due to accidental machine start-up!
7
5
3
4

Proper Use
9
2 Proper Use
The PFAFF 918 is a high-speed zigzag seamer with a drop feed and large hook.
The PFAFF 918 U is a high-speed zigzag seamer with a drop feed, large hook and
mechanical change-over from zigzag to 3-stitch zigzag.
The PFAFF 938 is a high-speed zigzag seamer with a drop feed.
The PFAFF 938 U is a high-speed zigzag seamer with a drop feed and mechanical change-
over from zigzag to 3-stitch zigzag.
The machines are used for sewing lockstitch seams in the clothing and underwear
industries.
Any usage not approved by the manufacturer is deemed misuse! The
manufacturer shall assume no liability for damage caused by misuse! Proper
use also includes compliance with the operating, maintenance, adjustment and
repair measures specified by the manufacturer!

Technical Data
10
3 Technical Data s
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
Clearance beneath the sewing foot: .................................................................................7 mm
Passage width:..............................................................................................................260 mm
Clearance height: ..........................................................................................................130 mm
Bed plate dimensions: ........................................................................................ 476 x 177 mm
Sewing head dimensions:
Length:.............................................................................................................approx. 550 mm
Width: .............................................................................................................. approx. 180 mm
Height (above table): ........................................................................................approx. 300 mm
Max. stitch length
PFAFF 918-6/01: .............................................................................................................4.5 mm
PFAFF 938-6/01; -6/27:...................................................................................................2.5 mm
Max zigzag stitch width
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
Max. stitch count
PFAFF 918:................................................................................................. 5000 stitches/min u
PFAFF 938-6/01; -771/05-6/27:....................................................................5500 stitches/min u
PFAFF 938-34/01 R: ................................................................................... 6000 stitches/min u
Connection data:
Operating voltage: ............................................................................... 230 V ± 10 %, 50/60 Hz
Motor data: ................................................................................. see motor instruction manual
Noise data:
Noise emission level at workplace with a sewing speed of n=4000 min-1:.... LpA < 80 dB(A) n
(Noise measurement in accordance with DIN 45 635-48-A-1, ISO 11204,
ISO 3744, ISO 4871)
Net weight of sewing head: .................................................................................approx. 46 kg
Gross weight of sewing head: ..............................................................................approx. 54 kg
sSubject to alterations
uDepending on the material, workstep and stitch length
nKpA = 2.5 dB

Technical Data
11
3.02 PFAFF 918 U, 938 U s
Stitch type:.............................................................................................. 304 (zigzag lockstitch)
Needle system:................................................................................................................... 438
Needle size in 1/100 mm:
Model A: ......................................................................................................................... 60 - 70
Model B: ....................................................................................................................... 80 - 100
Clearance beneath the sewing foot: .................................................................................7 mm
Passage width:..............................................................................................................260 mm
Clearance height: ..........................................................................................................130 mm
Bed plate dimensions: ........................................................................................ 476 x 177 mm
Sewing head dimensions:
Length:.............................................................................................................approx. 550 mm
Width: .............................................................................................................. approx. 180 mm
Height (above table): ........................................................................................approx. 300 mm
Max. stitch length: .........................................................................................................2.5 mm
Max zigzag stitch width
PFAFF 918 U: ............................................................................................................... 10.0 mm
PFAFF 938 U: .................................................................................................................6.0 mm
Max. stitch count:
For a needle bar stroke of 33 mm:..............................................................4500 stitches/min u
Connection data:
Operating voltage: ............................................................................... 230 V ± 10 %, 50/60 Hz
Motor data: ................................................................................. see motor instruction manual
Noise data:
Noise emission level at workplace with a sewing speed of n=3600 min-1: . LpA < 78.5 dB(A) n
(Noise measurement in accordance with DIN 45 635-48-A-1, ISO 11204, ISO 3744,
ISO 4871)
Net weight of sewing head:..................................................................................approx. 46 kg
Gross weight of sewing head: ..............................................................................approx. 54 kg
sSubject to alterations
uThe max. stitch count is automatically reduced within the max. preset value depending on
the stitch length.
nKpA = 2.5 dB

Disposal of the Machine
12
4 Disposal of the Machine
OIt is up to the customer to dispose of the machine properly.
OThe materials used for the machine include steel, aluminium, brass and various plastics.
The electrical equipment consists of plastics and copper.
OThe machine must be disposed of in accordance with the locally valid environmental
protection regulations, with a specialised company being contracted if necessary.
Please ensure that parts coated with lubricants are disposed of separately in
accordance with the locally valid environmental protection regulations!

Transport, Packaging and Storage
13
5 Transport, Packaging and Storage
5.01 Transport to the customer's premises
All machines are completely packed for delivery.
5.02 Transport within the customer's premises
The manufacturer assumes no liability for transport within the customer's premises or to
the individual usage sites. Please ensure that the machines are only transported in a vertical
position.
5.03 Disposal of the packaging materials
The packaging materials of these machines consist of paper, cardboard and VCI fleece.
It is up to the customer to dispose of the packaging properly.
5.04 Storage
The machine can be stored for up to 6 months when not in use. It must then be protected
from dirt and moisture. For longer storage periods, the machine's single components,
especially its sliding surfaces, must be protected against corrosion, e.g. by an oil film.

Work Symbols
14
6 Work Symbols
Activities to be performed or important information in this instruction manual are empha-
sised by symbols. The symbols used have the following meaning:
Note, information
Cleaning, care
Lubrication
Maintenance, repairs, adjustment, service work
(only to be carried out by technical staff)

Operating Controls
15
7.02 Keys on the machine head (only in machines with a flange motor)
The machine sews backwards if the key
1is pressed during the sewing operation.
The keys 2and 3can be assigned
through the corresponding parameter
settings (see separate parameter list).
7 Operating Controls
7.01 Main switch
Fig. 7 - 01
1
Fig. 7 - 02
2
1
3
Before switching on the
machine, raise the take-up lever
as far as possible.
Turning the main switch 1switches the
machine on and off.
7.02a Lower thread control (only on machines with lower thread monitor -926/04)
When reaching the amount of residual thread, the light-emitting diode 4flashes (see Fig. 7 - 02)
and the information 3217 appears in the display.
Now the remaining stitch number (o0605) can be sewn on. With o0606 = 1 the machine
stops when the residual density has expired.
The message is acknowledged with the "Reset" key. If o0606 and o0608 are switched on,
the drive stops after the number of stitches has expired. It can not be sewn again until the
message has been acknowledged with the "Reset" button. If o0608 is switched off, position
can be sewn again after pedal 0.See separate operating instructions P40 CD Chapter 5.3.3
Set remaining thread monitor and activate chapter 5.3.4 remaining thread monitor.

Operating Controls
16
Fig. 7 - 04
Fig. 7 - 03
7.03 Adjusting levers for zigzag stitch and needle position
OThe adjusting lever 1is used to adjust
the zigzag stitch width.
OThe locking lever 2must be pressed
against the adjusting lever 1to adjust the
adjusting lever.
The set zigzag stitch width is
shown on the scale 3.
OThe required needle position can be set
by turning the needle position adjusting
lever 4.
L= Needle position on the left
M= Needle position in the centre
R= Needle position on the right
1
2
R
3
L
4
M
7.04 Reverse-feed key / stitch length adjusting wheel
OThe machine sews backwards if the
reverse-feed key 1is pressed while
sewing.
OThe stitch length can be set by turning
the stitch length adjusting wheel 2.
OThe stitch length setting is shown on the
scale 3.
12
3

Operating Controls
17
Fig. 7 - 05
7.06 Lever to raise the sewing foot
OTurning the hand lever 1raises the
sewing foot.
1
7.05 Adjusting wheel for multi-stitches and zigzag stitches
(only on the PFAFF 918 U and 938 U)
Before starting to sew, make
sure that the adjusting wheel
1is engaged! Only make the
change-over when the machine
is at a standstill! Danger of
machine damage!
OTurning the adjusting wheel 1switches
between multi-stitches and zigzag
stitches, see chapter 9.10 Setting multi-
stitches and zigzag stitches.
Fig. 7 - 06
1

Operating Controls
18
0
1
2
3
4
7.08 Adjusting lever for under-edge trimmer -771/05
OThe under-edge trimmer is switched on
and the knife stroke is set by pulling and
pushing the lever 1in the direction of “+”.
Do not reach into the knife dur-
ing operation!
Risk of injury from the knife
moving upwards and down-
wards.
Fig. 7 - 08
1
7.09 Control panel (only in machines with P40 CD)
The description can be found in the separate instruction manual for the drive.
7.07 Pedal
OWith the main switch turned on
0= Neutral position
+1= Sewing
-1= Raise sewing foot
(in machines with automatic
presser foot lift -910/..)
-2= Trim thread
(in machines with thread trimmer
-900/..)
Fig. 7 - 07
-1
+1
0
-2

Set-up and Initial Start-up
19
Fig. 8 - 01
OLoosen the screws 1and 2.
OMove the table top to the desired working height by pulling it out and pushing it in and
align the table top horizontally.
Adjust the stand on both sides evenly to prevent it tilting.
OThe stand must have all four feet firmly on the ground to make sure it is positioned
securely.
OFirmly tighten the screws 1.
OAdjust and tighten the desired pedal position on the screws 2.
8 Set-up and Initial Start-up
The machine may only be set up and started up by qualified personnel! All of
the relevant safety regulations must always be complied with in this process!
If the machine was delivered without a table, then the stand and the table top
provided must safely support the weight of the machine and its motor.
Adequate stability of the stand must be guaranteed – even during the sewing
operations.
8.01 Set-up
Suitable electrical supply connections must be provided at the erection site, see chapter 3
Technical Data. The erection site must also have a firm and level subsurface and adequate
lighting.
The table top is lowered for packaging purposes.
The adjustment of the table height is described below.
8.01.01 Setting the table height
2
11

Set-up and Initial Start-up
20
Fig. 8 - 02
8.01.02 Inserting the sewing machine into the stand
OThe hinge 1is screwed to the sewing head base plate.
OInsert the sewing machine into the table top.
OInsert the sewing head support 2into the table top hole.
1
Do not operate the machine without the support 2! Risk of damage due to the
top-heavy sewing head!
Machine can tip over backwards when moving it!
1
2