Pfaff 481 User manual

481
Service Manual
PFAFF INDUSTRIEMASCHINEN GMBH KAiSERSLAUTERN
From the library of: Superior Sewing Machine & Supply LLC

Instructions for Adjusting the Pfaff 481
and Illustrated Guide for Tape-Recorded Instructions
Important note
Never use a C-clamp on the needle bar of Pfaff 480 series machines because this would
damage Its special coating. Furthermore, all adjustments which are to be made at a stitch
length of "0" on Model Nmachines have to be carried out at a stitch length of 1.5 mm and
with the reverse-feed control depressed, that means with the machine set for sewing back
wards at a stitch length of 1.5 mm.
The machine can be blocked at certain positions by Inserting a 5-mm-thlck pin In one of
the holes In the bearing plate which Is located underneath the face cover. When Inserting
the pin, be sure to push It In until Itenters the slot In the disc behind the bearing plate. For
easy Identification, the Individual holes are marked by the numbers 1 to 5 or by the appro
priate adjustment data. The abbreviations used In this connection stand for the following:
n. o. T. = past the top of the needle bar stroke
n. u. T. = past the bottom of the needle bar stroke
o. T. N. = top of needle bar stroke
o. T. F. = top of take-up lever stroke
Schl.-H. = 1.8 mm past the bottom of the needle bar stroke
The following tools, gauges and accessories are required for adjusting the Pfaff 481;
1 set of screwdrivers with blades from 2 — 10 mm wide
1 set of alien keys ranging from 1.5 to 6 mm
1
set of spanners from 7 to 14 mm wide
1 22-mm spanner
1 metal rule
1cylindrical pin, 5 mm dia.. Order No. 13-030341-05
1 universal gauge. Order Nr. 61-111642-19
1 wrapper with System 134 needles
1 strip of white paper, sewing thread and material for testing purposes.
From the library of: Superior Sewing Machine & Supply LLC

Preparations for adjusting
1.
Note:
The machine can be blocked at different positions by inserting the 5-mm-
thick pin in the appropriate hoie of the bearing plate. For easy identifica
tion, the holes in the bearing plate are marked by numbers or the appro
priate adjustment data (Fig. 1.0.1.).
Fig. 1.0.1.
1.1. Remove the belt guard.
1.2. Take out both screws of the face cover and remove it.
1.3. To block the machine at the various positions, proceed as follows:
1.3.1. Turn the balance wheel to bring the needle bar to the desired position.
1.3.2. Push the pin into the hole until it enters the slot in the disc behind
bearing plate.
1.4. The function of each of the five holes is as follows:
1.4.1. Hole 1 (0.6 n. o. T.) = 0.6 mm past the top of the needle bar stroke.
1.4.2. Hole 2 (o. T. F.) = top of take-up lever stroke.
1.4.3. Hole 3 (0.6 n. u. T.) = 0.6 mm past the bottom of the needle bar stroke.
1.4.4. Hole 4(Schl.-H. 1.8) = 1.8 mm past the bottom of the needle bar stroke.
1.4.5. Hole 5 (o. T. N.) = top of needle bar stroke.
1
the
From the library of: Superior Sewing Machine & Supply LLC

2.
Correct
setting:
2.1.
2.2.
2.3.
2.4.
2.4.1.
2.4.2.
2.4.3.
2.4.4.
2.4.5.
2.4.6.
2.4.7.
2.4.8.
Zeroing the feed motion
The feed dog must not move when you turn the balance wheel with the
stitch length control set at "0".
%
Fig. 2.0.1.
Remove the needle from the needle bar.
Raise the presser bar iifter.
Remove the knee lever together with its joint and tilt the machine back.
Adjustment procedure to be applied when the gearcase is open (Fig. 2.0.1.)
Turn the stitch iength control to "0".
Take out the 16 screws of the gearcase cover and remove the cover with its
gasket, making sure that the oil, if any, is drained off into a container.
Take the oil sponge out of the gearcase.
Loosen both clamp screws 2 of feed crank 1 just sufficiently to allow the crank
to be turned on its shaft against resistance.
To faciiitate adjustment, insert a screwdriver in the slot of feed rock shaft
crank 3 (see Fig. 2.0.1.).
Rotate the balance wheel and at the same time adjust feed crank 1 on Its
shaft until the feed dog (or rather the screwdriver in feed rock shaft crank 3)
no longer moves.
Tighten both clamp screws 2 of feed crank 1.
Check this adjustment (see top of page).
From the library of: Superior Sewing Machine & Supply LLC

Note: The feed motion can also be zeroed with the gearcase ciosed (see Fig. 2.O.2.).
Qb
^ r
Fig. 2.0.2.
2.5. Adjustment procedure to be applied when the gearcase cover is closed (Fig.
2.O.2.).
2.5.1. Turn the stitch iength control to "0".
2.5.2. Push a 22-mm open-ended spanner over hexagon tension nut 1 and hold
feed regulator shaft 2 fast with it.
2.5.3. Loosen clamp screw 4 of feed regulator crank 3.
2.5.4. With
the aid of the spanner pushed over hexagon tension nut 1 turn feed
regulator shaft 2 until the feed dog (or rather the screwdriver In feed rock
shaft crank 3) remains absolutely still when the balance wheel Is turned.
2.5.5. Hold the spanner in this position and tighten clamp screw 4, making sure
there is a clearance of 5 mm between feed regulator crank 3 and the casting.
2.5.6. Check this adjustment (see top of page 2) and pull the screwdriver out of the
slot of the feed rock shaft crank.
From the library of: Superior Sewing Machine & Supply LLC

Correct
setting:
Feed lifting motion
The feed dog should be at Its highest point when the needle bar Is at a
position 0.6 mm past the bottom of its stroke (pin in hole 3). In this position,
the notch in the feed lift eccentric should be positioned perpendicularly
below the center of the shaft (Fig. 3.O.2.).
Fig. 3.0.2.
I."
Fig. 3.0.1.
3.1. Loosen both screws 2 of feed lift eccentric 1.
3.2. Bring the needle bar to a position 0.6 mm past the bottom of its stroke and
block the machine In this position by Inserting the pin In hole 3.
3.3. Turn feed lift eccentric 1 until its notch points exactly downwards (see dash-
dot line In Fig. 3.O.2.), I. e. the feed dog is at its highest point.
3.4. In this position, securely tighten both screws 2.
3.5. Leave the pin In the hole of the bearing plate.
3.6. Check this adjustment (see top of page).
From the library of: Superior Sewing Machine & Supply LLC

Correct
setting:
Feed dog height
The feed dog should be positioned in the middle of its slots and contact
the gauge throughout its entire length when the stitch length control is set
at "0" and the needle bar is at a position 0.6 mm past the bottom of its
stroke (pin in hole 3). (Fig. 4.0.2.)
Fig. 4.0.2.
4.1. Turn the stitch length control to "0" and check to make sure the pin is
inserted in hole 3.
4.2. Loosen clamp screw 2 of feed lift crank 1.
4.3.
Loosen both ciamp screws 4 in feed rock shaft crank 3.
4.4. Place the universal gauge under the presser foot so that the arrow points in
the direction of feed and its front edge is flush with the front edge of the
needle plate.
4.5. Lower the presser bar lifter to rest the presser foot on the gauge.
4.6. Position the feed dog in the middle of its slots (Fig. 4.O.2.).
4.7. Push the feed bar upwards until the feed dog contacts the gauge and hold
the feed dog in this position.
4.8. Turn eccentric bushing 5 underneath feed rock shaft crank 3 until the feed
dog is in contact with the gauge throughout its entire length (Fig. 4.O.2.).
4.9. Tighten both
clamp screws 4 of feed rock shaft crank 3, making sure that the
feed dog is still centered in its slots.
4.10. Check to make sure that the feed dog is still in contact with the gauge
throughout its entire length and firmly tighten clamp screw 2 of feed lift
crank 1.
4.11. Raise the presser bar lifter, remove the gauge from under the presser foot, and
pull the pin out of the hole in the bearing plate.
4.12. Check this adjustment (see top of page).
From the library of: Superior Sewing Machine & Supply LLC

5.
Correct
setting:
6.1.
5.2.
5.3.
5.4.
5.5.
5.6.
5.7.
5.8.
5.9.
Feed driving motion
The feed dog should not move when the reverse-feed control Is moved up
and down with the machine set for Its longest stitch and the needle bar
set 0.6 mm past the bottom of Its stroke (pin In hole 3).
QC
Loosen both screws 2 of feed driving eccentric 1.
Bring the needle bar to a position 0.6 mm past the bottom of Its stroke and
block the machine In this position by inserting the pin In hole 3.
Set the machine for Its longest stitch.
To facilitate adjustment, push the screwdriver Into the slot of feed rock shaft
crank 3 (Fig. 5.0.1.).
Move the reverse-feed control up and down and simultaneously turn the feed
driving eccentric until its notch is visible and the feed dog (or rather the screw
driver In feed rock shaft crank 3) is completely motionless (Fig. 5.0.1.).
In this position, tighten the accessible screw 2 In feed driving eccentric 1.
Pull
the pin out of the hole in the bearing plate and tighten the second screw
2 In feed driving eccentric 1.
Check this adjustment (see top of page).
Pull the screwdriver out of the slot In the feed rock shaft crank.
From the library of: Superior Sewing Machine & Supply LLC

6.
Correct
setting:
Zeroing the needle feed motion
The needle bar should make no feed motion when the balance wheel is
turned with the stitch length control set at "0".
Fig. 6.0.1.
Fig. 6.0.2.
6.1. Turn the stitch length control to "0".
6.2. To facilitate
zeroing the needle feed motion, insert a screwdriver in the slot of
needle feed driving crank 3 (Fig. 6.O.2.).
6.3. Take out the two screws in the cover at the back of the machine.
6.4. Loosen clamp screw 1 of needle feed regulating crank 2 (Fig. 6.0.1.).
6.5. Adjust needle feed regulating crank 2 so that the needle bar makes no feed
motion when the balance wheel is turned (I.e. that the screwdriver in needle
feed driving crank 3 remains still).
6.6. In this position, securely tighten clamp screw 1 of needle feed regulating
crank 2.
6.7. Check this adjustment (see top of page).
6.8. Leave the screwdriver in the slot of driving crank 3.
From the library of: Superior Sewing Machine & Supply LLC

7.
Correct
setting:
Timing the needle feed motion
Both the needle bar and the feed dog should remain motionless when the
reverse-feed control Is moved up and down with the machine set for Its
longest stitch and the needle bar set 0.6 mm past the bottom of Its stroke
(pin In hole 3).
Fig. 7.0.1.
7.1. Loosen both screws 1 in needle feed eccentric 2.
7.2. Bring the needle bar to a position 0.6 mm past the bottom of Its stroke and
block the machine In this position by Inserting the pin In hole 3 of the bearing
plate.
7.3. Turn needle feed eccentric 2 so that Its slot points forward (see arrow In Fig.
7.0.1.).
7.4. Set the machine for its longest stitch.
7.5. Move reverse-feed control 4 up and down and simultaneously turn needle feed
eccentric 2until the needle bar remains still (I. e. until the screwdriver In needle
feed driving crank 3 Is completely motionless).
7.6. In this position, tighten the accessible screw 1 In needle feed eccentric 2.
7.7. Pull the pin out of the hole In the bearing plate and tighten the second screw 1
in needle feed eccentric 2.
7.8. Check this adjustment (see top of page).
7.9. Remove the screwdriver from driving crank 3.
8
From the library of: Superior Sewing Machine & Supply LLC

8.
Centering the needle in the needle hole
Correct When the feed dog is at Its highest point, the needle should be positioned
setting; exactly In the middle of the needle hole both lengthwise and crosswise
(Fig. 8.O.3.).
Ffg. 8.0.3
Fig. 8.0.1.
Fig. 8.0.2.
8.1. Bring the needle bar to Its highest point and remove the presser foot.
8.2. Insert a new System 134 needle Into the needle bar and push It up as far as
It will go, making sure its long groove faces toward the left.
8.3. Turn the stitch length control to "0".
8.4. Loosen clamp screw 1 of needle feed driving crank 2 (Fig. 8.0.1.).
8.5. Loosen screw 3 In the lug of the needle bar frame (Fig. 8.O.2.).
8.6. Rotate the balance wheel and simultaneously adjust the position of needle bar
frame 4 until the needle enters
the needle hole In the feed dog.
8.7. Bring the needle bar to Its lowest point and adjust needle bar frame 4 so that
the needle Is centered exactly In the needle hole, both lengthwise and cross
wise of the sewing direction (Fig. 8.O.3.).
8.8. In this position, tighten clamp screw 1 In driving crank 2.
8.9. Turn the balance wheel a few turns to ensure that the needle bar Is not under
stress In needle bar frame 4, and tighten screw 3.
8.10. Check this adjustment (see top of page).
From the library of: Superior Sewing Machine & Supply LLC

Eliminating feed differences
Correct With the machine set for Its longest stitch, both the feed dog and the needle
setting; should make feed strokes of the same length when the balance wheel is
turned.
Fig. 9.0.1.
(2)
9.1. Set the machine for Its longest stitch.
9.2. Loosen nut 1 on hinge stud 2 of regulating crank 3.
9.3.
Move hinge stud 2 in the fork of regulating crank 3, as appropriate. Moving
the stud toward the regulating shaft decreases the needie feed stroke, moving
it in the opposite direction increases it.
9.4.
Tighten nut 1 on hinge stud 2.
9.5. Check whether the needle feed is still zeroed properly (see Chapter 6) and
adjust, If necessary.
9.6. Check this adjustment (see top of page).
10
From the library of: Superior Sewing Machine & Supply LLC

10.
Correct
setting;
10.1.
10.2.
10.3.
10.4.
10.5.
10.6.
10.7.
10.8.
10.9.
10.10.
10.11.
10.12.
10.13.
Hook shaft bearing and gear play
There should be a clearance of 0.3 mm between sewing hook and oil
distributor ring when the hook point is opposite the needle and both these
parts are 0.1 mm apart (Fig. 10.0.2.). Also there should be a minimum of
play between the gears.
Fig. 10.0.2
C®
Fig, 10.0.1
Remove needle plate and feed dog, turn the stitch length control to "0".
Loosen screw 1 of oil regulating valve 2 and swivel the oil tube of valve 2 out
of oil distributor ring 3.
Loosen alien screw 4 of eccentric hook shaft bearing 5 on the top surface of
the bedplate (Fig. 10.0.2.).
Turn eccentric hook shaft bearing 5 so that the recess (see arrow in Fig.
10.0.1.) Is visible from below and the two spur gears have neither too much
play nor stand too close together.
Loosen both hook set screws 6.
Push the sewing hook against the oil distributor ring.
Bring the needle bar to its lowest point, making sure that the needle does not
strike the sewing hook.
Reposition hook shaft bearing 5 in the casting until there is a clearance of
0.4 mm between hook point and needle. Make sure however that you do not
turn the bearing and that the hook remains in contact with the oil distributor
ring.
With the bearing in this position, tighten alien screw 4.
Loosen both screws 8 in large spur gear 7.
Reposition spur gear 7 on Its shaft until It Is exactly in line with the small
spur gear.
Tighten both screws 8 securely, making sure that the second screw of spur
gear 7 — as seen in its direction of rotation — is positioned in the groove
of the shaft.
Do not tighten hook set screw 6 as yet and leave the oil tube swivelled away.
11
From the library of: Superior Sewing Machine & Supply LLC

11.
Correct
setting:
Needle bar height, hook timing and hook-to-needle clearance
The needle bar should be set
vertically so that the top edge of the needle
eye Is positioned 0.8 mm below the bottom edge of the hook point (Fig.
11.0.2.). The amount of needle rise required to form the loop Is 1.8 mm
(pin In hole4),the hook-to-needle clearance 0.1 mm.
Fig. 11.0.2
Fig. 11.0.1.
11.1. Bring the needle bar to a point 1.8 mm past the bottom of Its stroke, making
sure though that the needle does not strike the sewing hook. Block the
machine In this position by Inserting the pin In hole 4.
11.2. Make sure the stitch length control Is set at "0".
11.3. Loosen both clamp screws 2 In needle bar connecting stud 1.
11.4. Turn the sewing hook on Its shaft until Its point Is exactly opposite the center
line of the needle.
11.5. Move the needle bar up or down until there is a clearance of 0.8 mm between
the top edge of the needle eye and the bottom edge of the hook point (Fig.
11.0.2.); the hook point Is now positioned approximately In the middle of the
needle scarf.
11.6. In this position, tighten both clamp screws 2, making sure that the needle set
screw points exactly to the right.
11.7. Adjustthe sewing hook until there is a clearance of 0.1 mm between Its point
and the needle (center of scarf); make sure that the position finger Is still In
the slot of the bobbin case.
11.8. In this position, tighten the accessible hook set screw.
11.9. Pull the pin out of the hole In the bearing plate and tighten the second hook
set screw.
11.10. Check this adjustment (see top of page).
12
From the library of: Superior Sewing Machine & Supply LLC

12.
Correct
setting:
12.1.
12.2.
12.3.
11.4.
12.5.
Vertical position of bobbin case opener
When at its left point of reversal, bobbin case opener finger 3 stiouid be
positioned vertically so that it is exactly opposite the lug of bobbin case
base 4 (Fig. 2.O.2.).
Fig. 12.0.2
m
Fig. 12.0.1.
Loosen screw 1 of eccentric bobbin case opener shaft bushing 2.
Turn the balance wheel to bring the opener finger to its left point of reversal.
Turn bushing 2 until opener finger 3 Is exactly opposite the lug of bobbin
case base 4.
In this position, tighten screw 1 of bushing 2.
Check this adjustment (see top of page).
13
From the library of: Superior Sewing Machine & Supply LLC

13.
Correct
setting:
Position of bobbin case opener
There should be a clearance of 0.8 mm between bobbin case opener finger
1 and bobbin case base 5 (Fig. 13.0.2.). Furthermore, when opener finger 1
is at the left of its stroke, there should be a clearance of 0.3 mm between
position finger 6 and bobbin case base 5 (Fig. 13.0.3.). In this position, the
lug on collar 4 should be up against the stop of opener finger 1 (Fig.
13.0.1.).
Fig. 13.0.2.
Fig. 13.0.3.
13.1. Loosen screw 3 of collar 4.
13.2. Loosen clamp screw 2 of opener finger 1 just sufficiently to allow it to be
turned on Its shaft against resistance.
13.3. Reposition opener finger 1 on its shaft until there is a clearance of 0.8 mm
between it and bobbin case base 5 (Fig. 13.0.2.).
13.4. Rotate the balance wheel until opener finger 1 is at the left of its stroke.
13.5. Turn opener finger 1 until there is a clearance of 0.3 mm between position
finger 6 and the right wall of the position siot In the bobbin case base when
opener finger 1 contacts the lug of bobbin case base 5 (Fig. 13.0.3.).
13.6. In this position, tighten clamp screw 2 of opener finger 1.
13.7.
Push collar 4 up against opener finger 1 and turn it so that its lug is up against
the stop of opener finger 1.
13.8. In
this position, tighten screw 3 of collar 4.
13.9. Check this adjustment (see top of page).
14
From the library of: Superior Sewing Machine & Supply LLC

14.
Correct
setting:
Timing the bobbin case opener
When the needle bar has risen 1.8 mm from the bottom of its stroke (pin
in hole 4), opener finger 3 should be at the right of its stroke (Fig. 14.0.2.).
Fig. 14.0.2.
14.1. Loosen both screws 2 of bobbin case opener eccentric 1.
14.2. Bring the needle bar to a position 1.8 mm past the bottom of its stroke and
block the machine in this position by inserting the pin in hole 4.
14.3. To facilitate determining the exact point of reversal insert a small screwdriver
in the slot of the clamp of opener finger 3.
14.4. Turn opener eccentric 1 until opener finger 3 is at its right point of reversal.
14.5. In this position, tighten the accessible screw 2 of opener eccentric 1.
14.6. Pull the pin out of the hole in the bearing plate and tighten
the second screw
2 also.
14.7. Puii the screwdriver out of the clamp slot and check this adjustment (see top
of page).
15
From the library of: Superior Sewing Machine & Supply LLC

15.
Correct
setting;
Oil tube In oil distributor ring
Oil tube 1 should be positioned in the hole of oil distributor ring 2 (Fig.
15.0.2.).
Fig. 15.0.2.
m
Fig. 15.0.1.
15.1. Insert oil tube 1 into the hole of oil distributor ring 2 (see arrow in Fig. 15.0.2.);
If necessary, turn the oil distributor ring accordingly.
15.1.1. On subcl. -900 machines the oil distributor ring cannot be turned until you
have loosened the three
screws on the front side of the hook shaft bearing.
15.2. Tighten screw 3 of oil regulating valve 4 (Fig. 15.0.1.).
16
From the library of: Superior Sewing Machine & Supply LLC

16. Oil check valve
Correct There should be a clearance of 1.0 mm between actuating rod 3 of the
setting: centrifugal governor and push rod 4 of the oil check valve (Fig. 16.0.2.).
Fig. 16.0.2
Fig. 16.0.1
16.1. Loosen screw 1 of oil check valve 2.
16.2. Push actuating rod 3 to the left as far as it will go.
16.3. Push push rod 4 into oil check valve 2 until a resistance is felt.
16.4. Reposition oil check valve 2 until there is a clearance of 1.0 mm between
actuating rod 3 and push rod 4.
16.5. In this position, tighten screw 1 of oil check valve 2.
16.6. Check this adjustment (see top of page).
16.7. Soak the oil sponge with oil and replace it in the gearcase so that its large
recess Is at the bottom left and the oil tube is placed on top of it.
16.8. Clean the gasket face on the gearcase and the gasket of the gearcase cover.
16.9. Replace the gearcase cover and simultaneously screw on the two machine
legs, tightening the screws of the cover crosswise.
17
From the library of: Superior Sewing Machine & Supply LLC

17.
Correct
setting:
17.1.
17.2.
17.3.
17.4.
17.5.
17.6.
17.7.
17.8.
Hook lubrication
After the machine has run at fuli speed for about ten seconds, afine trace
of oii shouid appear on a piece of paper placed over the needle plate
cutout above the hook raceway.
Fig
Turn in regulating screw 1 of oii regulating valve 2 as far as it will go, and
then back about three turns.
Switch on the machine and run it until the sewing hook starts emitting oil.
Turn regulating screw 1 in completely and then out half a turn.
Let the machine run about one minute.
Place a piece of white paper over the needle plate cutout.
Let the machine run about ten seconds. Then check to see if a fine trace
of oii has appeared on the paper opposite the hook raceway.
If too much oil Is emitted, turn regulating screw 1 In a little; or If too little
oil Is emitted, turn it out somewhat.
Check this adjustment (see top of page).
18
From the library of: Superior Sewing Machine & Supply LLC