Pfaff 3538-20/02 Guide

This adjustment manual applies to machines from the
following serial numbers onwards:
# 2 804 345
3538
296-12-19 293/002
Adjustment manual engl. 08.18
ADJUSTMENT MANUAL
-20/02
-30/02

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
13 Adjustment ....................................................................................................4
13.01 Notes on adjustment ............................................................................................................. 4
13.02 Tools, gauges and other accessories .................................................................................... 4
13.03 Abbreviations ......................................................................................................................... 4
13.04 Explanation of symbols.......................................................................................................... 4
13.05 Adjusting basic machine ........................................................................................................ 5
13.05.01 Needle height (pre-calibrating) ............................................................................................... 5
13.05.02 Hook driving eccentric (pre-calibrating).................................................................................. 6
13.05.03 Feed lifting eccentric ............................................................................................................. 7
13.05.04 Spreader driving eccentric ..................................................................................................... 8
13.05.05 Feed driving eccentric and drive for needle bar frame .......................................................... 9
13.05.06 Feed dog position ................................................................................................................ 10
13.05.07 Feed dog height................................................................................................................... 11
13.05.08 Needle position to needle hole ............................................................................................ 12
13.05.09 Hook position crossways to sewing direction ..................................................................... 13
13.05.10 Readjusting hook position in sewing direction / hook eccentric .......................................... 14
13.05.11 Readjusting needle height ................................................................................................... 15
13.05.12 Spreader position in sewing direction.................................................................................. 16
13.05.13 Spreader position crossways to sewing direction ............................................................... 17
13.05.14 Needle guard and thread-loop support ................................................................................ 18
13.05.15 Compensation weight.......................................................................................................... 19
13.05.16 Feed difference.................................................................................................................... 20
13.05.17 Clearance between presser foot and needle plate .............................................................. 21
13.05.18 Needle thread regulation and take-up lever guard ............................................................... 22
13.05.19 Looper thread regulation...................................................................................................... 23
13.05.20 Stitch length limitation ......................................................................................................... 24
13.05.21 Adjusting workpiece infeed and stop ................................................................................. 25
13.05.22 Sensors, settings ................................................................................................................ 26
13.05.23 Adjusting feed band on right, belt tension and belt height ................................................. 27
13.05.24 Adjusting feed band on left, belt tension and belt height ................................................... 28
13.05.25 Chain cutter, settings .......................................................................................................... 29
13.05.26 Feed mechanism: accepting pocket .................................................................................... 30
13.05.27 Feed mechanism: taking over pocket.................................................................................. 31
13.05.28 Adjusting protective cover on stacker and sensor .............................................................. 32
13.05.29 Round table, lift adjustment ................................................................................................ 33
13.05.30 Traversing unit .................................................................................................................... 34
14 Circuit Diagrams ................................................................................................................ 35
14.01 Circuit diagrams ................................................................................................................... 35

Adjustment
4
13 Adjustment
Observe and comply with all instructions in the operating manual’s chapter 1
Safety! In particular make sure that all safety covers are installed again correct-
ly after making adjustments, see chapter 1.06 Operating manual hazard infor-
mation!
Unless otherwise stated, the machine must be disconnected from the power
supply before all adjustment work!
Risk of injury due to accidental machine start-up!
13.01 Notes on adjustment
All adjustments in this manual are based on a fully assembled machine and may only be car-
ried out by technical staff trained for this purpose. Machine covers, which have to be re-
moved and replaced to carry out checks and adjustments, are not mentioned in the text.
The order of the following chapters corresponds to the most logical work sequence for ma-
chines that have to be completely adjusted. Both the preceding and following chapters must
be observed if only specific individual work steps are carried out. Screws and nuts indicated
in brackets ( ) are fastenings for machine parts, which must be loosened before any adjust-
ment and tightened again afterwards.
13.02 Tools, gauges and other accessories
O1set of screwdrivers with knife widths of 2to 10 mm
O1set of wrenches with jaw widths from 6to 22 mm
O1set of Allen keys of 1.5to 6mm
O1metal ruler (order no. 08-880 218-00
ONeedle rise gauge (order no. 61-111 600-01)
OScrew clamp (order no. 61-111 600-35)
OAdjustment pin (order no. 61-111 643-55)
ONeedles, system (62-57)
OThread and testing material
13.03 Abbreviations
t.d.c. = top dead centre
b.d.c. = bottom dead centre
13.04 Explanation of symbols
Activities to be performed or important information in this adjustment manual are empha-
sised by symbols. The symbols used have the following meaning:
Note, information
Maintenance, repairs, adjustment, service work
(only to be carried out by technical staff)

Adjustment
5
13.05 Adjusting basic machine
13.05.01 Needle height (pre-calibrating)
Rule
When the needle bar is in t.d.c., the clearance between the needle point and needle
plate should be approx. 12 mm with a needle bar stroke of 36 mm.
OAdjust the needle bar 1(screw 2) without twisting according to the rule.
Fig. 13 - 01
2
1
12 mm

Adjustment
6
13.05.02 Hook driving eccentric (pre-calibrating)
Rule
When the needle bar is in b.d.c., the round side of the adjustment pin 1
(order no. 61-111 643-55) should engage in the groove 5.
OInsert the adjustment pin 1in the hole 2.
OTurn the eccentric 3(screws 4) according to the rule.
ORemove the adjustment pin 1.
Fig. 13 - 02
1
3
2
3
4
5

Adjustment
7
13.05.03 Feed lifting eccentric
Rule
When the needle bar is in b.d.c., the groove 3should be positioned vertically above the
shaft 4.
OTurn the eccentric 1(screws 2) according to the rule.
Fig. 13 - 03
12
4
3

Adjustment
8
13.05.04 Spreader driving eccentric
Rule
1. When the needle bar is positioned 1 mm after b.d.c., the groove 5of the eccentric 1
should be positioned vertically above the shaft 3.
2. The spreader holder 4should move 6mm.
OTurn the eccentric 1(screws 2) according to rule 1or adjust (axially) according to rule 2.
Fig. 13 - 04
1
2
3
5
3
6 mm
4

Adjustment
9
13.05.05 Feed driving eccentric and drive to needle bar frame
Rule
When the needle bar is in b.d.c.,
1. the groove 7of the eccentric 1should be positioned vertically above the shaft 5and
2. the crank 3should be positioned vertically to the shaft 6
OTurn the eccentric 1(screws 2) according to rule 1.
OTurn the crank 3(screw 4) according to rule 2.
Fig. 13 - 05
3
6
4
2
7
5
1

Adjustment
10
13.05.06 Feed dog position
Rule
The feed dog 4should move laterally and longitudinally in the centre of the needle plate
recess at maximum stitch length.
OAlign the attachment 1(screws 2and 3) according to the rule.
Fig. 13 - 06
1
2
3
4
=
=

Adjustment
11
13.05.07 Feed dog height
Rule
When the needle bar is in b.d.c. and with maximum stitch length regulation, the front
teeth of the feed dog 2should be positioned 0.9 mm and the back teeth 1.2mm above
the needle plate.
OLoosen the screw 1
OMove the feed dog 2into an inclined position 0.3 mm to the back teeth.
OTighten the screw 1
OLoosen the screw 3
OAdjust the feed bar 4according to the rule.
OLoosen the nut 5on the stop screw 6.
OScrew in the stop screw 6up to the stop and secure it with the nut 5.
Fig. 13 - 07
2
4
3
6
5
2
0.9 mm
1
1.2 mm

Adjustment
12
13.05.08 Needle position to needle hole
Rule
1. The needle should pierce the middle of the needle hole crossways to the sewing di-
rection.
2. When the needle bar is in b.d.c., there should be a clearance of 0.4mm between
the needle and the front edge of the needle hole.
OAlign the needle bar frame (screws 1, 2and 3) according to rule 1.
OAdjust the needle bar (screw 3) according to rule 2.
Fig. 13 - 08
2
0.4 mm
1
3

Adjustment
13
13.05.09 Hook position crossways to sewing direction
Rule
The hooks 1should be parallel to the needle plate recess.
1. If the hook points are at the needle midpoint,
2. there should be a clearance of 0.1mm between the hook point and the needle.
Fig. 13 - 09
OSet the hook point at the needle midpoint by turning the handwheel.
OAlign the hook 1(screws 2) according to rule 1.
OAdjust the bracket 3(screws 4) according to rule 2.
1
4
3
1
0.1 mm
2

Adjustment
14
13.05.10 Readjusting hook position to sewing direction / hook eccentric
Rule
When the needle bar is positioned 4.2mm after b.d.c. and stitch length regulation is
4.5mm, the hook point should be at the needle midpoint.
Fig. 13 - 10
Adjusting the maximum stitch length
OMove the needle bar to a position 4.2mm after b.d.c. by turning the handwheel.
OSecure the c-clamp to the needle bar in this position so that the upward movement of
the needle bar is blocked.
OAdjust the bracket 1(screw 2) according to the rule.
Checking the hook driving eccentric
OTurn the handwheel against the direction of rotation until the c-clamp lays flat again.
OMeasure the clearance between the hook point and the edge of the needle - the clear-
ance should be 3.3mm.
OIn the event that this differs, turn the handwheel in the direction of rotation until the c-
clamp lays flat again and make the following adjustment:
OMeasured value is larger than 3.3mm, turn the eccentric 3(screw 4) so that the hook
moves to the left by half the value of the measured difference.
OMeasured value is smaller than 3.3mm, turn the eccentric 3(screw 4) so that the hook
moves to the right by half the value of the measured difference.
ORestore the setting indicated in the rule after a correction has been made to the eccen-
tric 3.
Maintain stitch length regulation for the next setting.
12
4
3

Adjustment
15
13.05.11 Readjusting needle height
Rule
If the hook point aligns with the front of the needle at maximum stitch length coming
from behind, the lower edge of the hook should be positioned 1.5– 2mm above the
needle eye.
Fig. 13 - 11
OAdjust the needle bar 1(screw 2) according to the rule.
OCheck the hook position in the sewing direction, see chapter 12.05.10 Hook position in
sewing direction.
1
2
1.5 - 2 mm

Adjustment
16
13.05.12 Spreader position in sewing direction
Rule
1. The spreader tip should be inclined approx. 45° downwards and be 11 mm away
from the spreader holder.
2. The clearance between the tip of spreader 1and the needle should be 2mm with
maximum stitch length regulation and the needle bar positioned in b.d.c.
Fig. 13 - 12
OAdjust the spreader 1(screws 2) according to rule 1.
OAdjust the bracket 3(screw 4) according to rule 2.
3
1
1
2
2
4
1
45°
2 mm
11 mm
1

Adjustment
17
13.05.13 Spreader position crossways to sewing direction
Rule
1. The tips of the spreader 1 should be 0.1 mm away from the hook at the side.
2. The tips of the spreader 1should be positioned 0.1mm above the back of the hook.
Fig. 13 - 13
OPlace the hook eye next to the tips of the spreader 1by turning the handwheel.
OAdjust the bracket 2(screws 3) according to rule 1.
OTurn the handwheel until the tips of the spreader 1are positioned above the back of the
hook.
OAdjust the bracket 2(screw 4) according to rule 2.
2
1
4
3
0.1 mm 0.1 mm
1
0.1 mm

Adjustment
18
13.05.14 Needle guard and thread-loop support
Rule
If the hook point is positioned at the needle midpoint coming from behind, the
1. guard 1should rest gently on the needle and the lower edge of it should be posi-
tioned 0.5mm above the needle point.
OAlign the guard 1(screws 2) according to rule 1.
13 - 14
2
1
0.5 mm

Adjustment
19
13.05.15 Compensation weight
Rule
When the needle bar is in t.d.c., the largest eccentricity of the compensation weight 1
should be in the bottom position.
Fig. 13 - 15
OTurn the compensation weight 1(screw 2) according to the rule.
2
1
1
2

Adjustment
20
13.05.16 Feed difference
Rule
The needle and bottom transporter should feed in the same way with maximum stitch
length regulation and when turning the handwheel.
OAdjust the connecting rod 1(nut 2) according to the rule.
OConnecting rod by “ +” = larger needle feed or
by “ -” = smaller needle feed.
Fig. 13 - 16
2
1
1
+-