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