Singer 271K User manual

>
Form 21303
(564)
SINGER
Service Manual
Class 271k
0
AUTOMATICALLY LUBRICATED ROTARY SEWING HOOK
FOR MAKING PURLSTITCH OR WHIPSTITCH BUTTONHOLES
*A Trademerk of THE SINGER COMPANY
THE SINGER COMPANY
Copyright ^ 1964 by The Singer Company
Copyright Under International Copyright Union
Alt Rights Reserved under Inler-American Copyright Union
Printed In U. S. A.
From the library of: Superior Sewing Machine & Supply LLC

Actuator Setting (Belt Shifter) 22
Adjustable Catch Function 15
Automatic Knife Bar
Disengaging Lever 10, 32
Automotic Sequential Buttonhole
Device 4
Automatic Sewing Cycle 3
Barring 24, 34
Barring Head 25
Barring Stitch 34
Bed Dimension 3
Belt 5
Belt Shifter, Actuator Setting 22
, Automatic 4
, Engaging Face Clearance 23
Moment of Trip 23
, Operating-block Setting 23
, Shaft Setting 22
, Timing 23
, Two Speeds 9
Bight Adjustment 10, 33, 34
Bight Stitch 34
Binding, Remedies 11
Bobbin Cose Cap, Threading 8
Bobbin Case Opener Bracket 6, 28
Bobbin Cose Stop Position 28
Bobbin Removal 8
Bobbin Thread Tension 9
Bobbin Winding 3, 8
Breoking of Thread, Remedies 11
Buttonhole, Completing 9
, Length 10
, Number of Stitches 12, 13
, Purl stitch 3, 4, 7, 9
,
Stitching over Twice 10
,
Whipstitch 3, 4, 7
Com Follower Position for Upper Thread
Cutting and
Clamping Blodes 30, 35, 36
Centralizing, Barring Stitches ^4
, Clamp Check 26
, Needle Plate 26
, Tie Stitches 33
Changing the Gears 12
Chort, Gear Selection 13
, Knives Furnished 18
Clamp, Placing Fabric beneath 9
Clamp Carrier Slide Lever 16
Clomp Check, Centered 26
, Clearance with Needle 27
, Raising 10
,Swing and Tilt 27
Clomp Lift, Clearance 3
Cleaning 6
Clearance, Clamp Check 27
, Clamp Lift 3
, Feed Wheel Tripping Lever. .. 21
, Interlocking Rod 20
, Starting Lever Rod 21
Cloth Plate, Front 4
Completing on Unfinished
Buttonhole 9
Cord, Threoding 7
Cord Finger, Adjustable Catch 5
, Height 14
, Rotating Sector 15
, Timing 15
, Tripping Latch 15
Cording 4, 5, 7, 14, 15
Critical Areas that May Cause
Thread Damage 11
INDEX
Cutting and Clamping Blades,
(Upper Thread),
Pressure Adjustment 29
,Removal and Replacement. 28, 29
, Re-trim Action (Timin g) 30
, Setting 29, 30, 35, 36
Cutting Blade, Under Thread 28
Cutting Space, Adjustment 16
Driven ond Driving Gears, Chort 13
Driving Arm Safety 36
Driving Lever Spring Tension 17
Feed, Description 3, 11-13
Feed Gears 11-13
Feed Wheel Tripping Lever,
Clearance 21
Feed Wheel Tripping Points 22
Front Hook Shaft Bushing 28
Fotl Speed, Operation (Belt Shifter). ... 9
Gears .3, 4, 11-13, 20, 21
Gear Changing 3, 12
Gear Selection 13
Half Speed, Adjustment (Stop Motion). . 19
, Function 3, 9
Hand Ratcheting 3, 9
High Point of Stop Cam 19
Hook 3, 6.
28, 31
Interlocking Rod, Clearance 20
, Tension 19
Knife, Alignment with Needle 16
, Replacement and Setting 16
Knife Bar
Disengaging Lever. 10, 32
Knife Bar Height 3, 17
Knife Bar Spring Tension 17
Knife Grinder, Oiling and
Operation 18
Knife Slit in Needle Plate 22
Knifes Available 3, 4, 18
Lotch Tripping Plate 31
Length of Buttonhole 10
Lubrication 5, 6, 8, 18, 28
Machine Pulleys, Description 3
, Rotation 5
Needle, Cataloque 1526(71xlY) 3, 6
Needle and Knife Alignment 16
Needle, Faults and Remedies 6, 11
, Setting 6
, Threading 7
Needle Bar Frame 33
Needle Bar Frame Pitman 16, 33
Needle Bar Height 26
Needle Bar Stroke 3
Needle Guard (Hook) 31
Needle Plate 26
Needle Threod Handling Ports
(Critical Areas that May Couse
• Thread Damage) 11
Needle Thread Pull-off 36
Needle Thread Tension 9, 14, 36
Normal Speed (Belt Shifter) 9
Number of Stitches in Buttonhole. ..12, 13
Oil Flow to Hook, Regulation 6
Oiling, Bobbin Winder 8
, Knife Grinder 18
, Machine 5
Ports, Illustrations and List 37
Placing Fabric under Clamp 9
Pressure on Upper Thread Cutting and
Clamping Blades 29
Pre-tension Control 14
Pulleys 3, 5
Ratcheting, Hand 3, 9
Safety Devices 3, 30, 31, 35, 36
Sewing Hook, Assembly. 31
,
Description 3
, Needle Guard 31
, Regulating Oil Flow 6
,
Setting and Timing 31
Sewing Safety Lever 35
Sewing Safety Lock 3, 30
Speed, Adjustment (Stop Motion} 19
, Changing (Belt Shifter} 9
, Maximum Recommended. .. 3, 4, 5
Starting Lever Engaging Handle 4
Starting Lever Rod, Clearance 21
Stitch Gears 3, 4, 1.1-13
Stitching over Twice on
Some Buttonhole 4, 10
Stitch Width 10, 24, 34
Stop Cam 3, 19-21
Stop Com Geor Spring 20, 21
Stop Motion 19-21
Stop Motion,
Clearance between Interlocking
Rod Guide and Lock Pin 20
, CIcoronce between Com Foce
and Interlocking Rod 20
, Excess Ploy between Com
and Pinion 19
, Half Speed Position 19
, High Point of Com 19
, Removing the Pulleys 21
,
Replacing the Stop Cam
Gear Spring 20, 21
, Stop-position Notch 19
, Tension on Interlocking Rod....19
Take-up Spring 14
Tension, Driving Lever Spring 17
, Knife Bar Spring 17
, Interlocking Rod 19
, Threads 9, 11, 14
Tension Releaser 32, 36
Thread 7, 11
Thread Breaking or
Fraying, Remedies 11
Thread Cutting 28-30
Threading 7, 8, 11
Tie Stitch 33
Tipping the Machine
for Adjustments 3
Top Cording 4, 5, 7, 14, 15
Trip Lever (Barring) 25
Tripping Latch Function 15
Tripping Lever Clearance
(Feed Wheel) 21
Tripping Plote ...31
Tripping Point (Barring) 25
Tripping Points (Feed Wheel) 22
Tripping Safety Lock 30
Two-speed Belt Shifter 3, 9
Under Thread Cutting Blade 28
Unfinished Buttonhole, completing. ... 9
Upper Thread Cutting and
Clamping Blades 28-30, 35, 36
Upper Threod Cutting Com.; 35, 36
Wheel Gears (Feed) 11-13
Whipstitch Buttonhole 3, 4, 7, 9
Width of
Borring Stitches 24, 34
Width of Bight 10, 33, 34
Winding
the Bobbin 8o
From the library of: Superior Sewing Machine & Supply LLC

DESCRIPTION
Machinesof Class 271Kstitch quality button
holes in light end medium weight materials at
speeds up to 3000
stitches per minute.
GENERAL CHARACTERISTICS
Single needle, Catalogue 1526 (71x1Y).
Lockstitch.
Fiat bed. Dimensions; length 15-11/32
inches, width 7 inches.
Automatically lubricated rotary sewing hook
with mechanical opener.
Automatic sewing cycle. Machine automati
cally
cuts and holds needle thread and cuts
bobbin thread and the buttonhole after stitching.
Cycle completed with take-up lever always at
highest point.
Tying stitches, made at beginning and at
end of each buttonhole,provide perfect starting
stitches and a securely fastened bar at finish.
Needle thread re-trimming device results in
closer, uniformly
trimmed thread ends.
Positive, gear-driven, continuous feed
spaces stitches evenly around buttonhole under
all conditions.
Stitch gear changes made without use of
speciol tools.
Unique two-speed drive automatically
slows
arm shaft to 1/2 speed before entering stop
position.
Shock-reducing knife bar stop provides
cushion of air so that knife bar returns quietly
and safely after cutting buttonholes.
Stop com driven at 1/4 of operating speed,
before entering stop (1/2 speed of
arm shaft), to
ensure positive stop with minimum strain on
stop motion.
Safety clamp lock prevents operator from
raising work clamp until buttonhole is com
pleted - - - preventing breakage of needle and
of trimmer parts.
Hand ratchet device enables operator to
easily restart stitching at any part of the button
hole.
Link take-up.
Bobbin winder attached to belt guard. (EX
CEPTION: Furnished on Machine 271K201 only
onrequest.)
Machine pulley (loose, double-shielded bear
ing) with belt groove diameter 2-3/4 for 5/16
inch round rubber (endless) belt.
Machine pulley (tight) 271617 drives machine
at 1/2 operating speed.
Machine pulley (positive drive) drives ma
chine, through gear train, at operating speed.
Needle bar stroke, 1-23/64 (1.359) inches.
Clearance under Clamp,
3/8 inch.
Machine can be tipped either toward left
or rear for easier servicing. (EXCEPTION:
Machine
271K201 is resiliently mounted and can
be tilted toward rear only.)
SPECIAL FEATURES OF
MACHINE VARIETIES
Machine 271K1 makes purlstitch or whip
stitch buttonholes with square barred ends in
dress and sport shirts, dresses, pajamas, under
wear, surgical uniforms, children's play cloth
ing, bathing
suits, blouses, skirts, housecoats
and similar articles of wear.
Regularly furnished to make square-barred or
wide-barred end buttonholes
3/8 to 3/4 inch long.
Upon specific request, machine can be fitted to
make buttonholes
3/8 to 1 inch long.
Stitch gears for 120
stitches (needle dips)
are furnished unless otherwise ordered. Stitch
gears for 60 to 360 stitches are supplied if
specified on order.
Knives furnished in
sizes 3/8, 1/2, 5/8
and 3/4 inch.
Maximum speed, 3000 stitches per minute.
3
From the library of: Superior Sewing Machine & Supply LLC

SPECIAL FEATURES OF
MACHINE VARIETIES
(continued)
Machine 271K2 makes purlstitch or whip
stitch buttonholes with elongated barred ends
in dress and sport shirts, dresses, pajamas, etc.
Machine is regularly furnished to make elon
gated bcrred-end buttonholes
from 3/8 to 11/16
inch long.
Stitch gears
for 144 stitches are furnished
unless otherwise ordered. Stitch gears for 60
to 360
stitches are supplied if specified on
order.
Knives furnished in sizes 3/8, 1/2, 5/8
and 11/16 inch.
Maximum speed 2700 stitches per minute.
Special instructions for Machine 271K2 be
gin on page 33.
Machine 271K3 makes extra-long, purlstitch
or whipstitch buttonholes with square barred
ends in dress and sport shirts; dresses, pajam
as, etc.
Machine is regularly furnished to make
square-barred or wide-barred end buttonholes
1 to 1-1/2 inches long. Upon specific request,
machine can be fitted to moke buttonholes 3/4
to 1-1/2 inches long.
Stitch gears for 216 stitches are furnished
unless otherwise ordered. Stitch gears for 60
to 360 stitches are supplied if specified on
order.
Knives furnished in sizes 1, 1-1/8, 1-1/4,
1-1/2 inches.
Maximum speed, 3000 stitches per minute.
Machines
271K4 makes extra-strong, whip
stitch, top corded buttonholes with square bar
at first end and taper bar at finishing end in
linen and cotton fabrics, knit goods, etc.
Cord is laid on top side of fabric under the
overseaming stitches. Machine automatically
cuts and holds needle thread and top cord and
cuts the buttonhole and bobbin thread aftet-
stitching.
Buttonhole
may be stitched over twice for
super-strength, by simply depressing starting
treadle again.
Machine is regularly furnished to moke but
tonholes 3/8 to 3/4 inch long.
Upon specific request, machine can be
fitted to moke buttonholes up to 1-1/4 inches
long, with square bar or NO bar at first end
and taper bar at finishing end.
Stitch gears for 100 stitches are furnished
unless otherwise ordered. Stitch gears for 60 to
360 stitches are supplied if specified on order.
Knives furnished in sizes 3/8, 1/2, 5/8 and
3/4 inch.
Maximum speed, 3000 stitches per minute.
Machine 271K201 especially designed for
installation on Automatic Sequential Button
hole Electro Mechanical Device 257464, is
similar to Machine 271K1 with the following
exceptions: —
Fitted with starting lever engaging handle to
manually start the machine, a front cloth plate
for controlling the cloth and an automatic belt
shifter.
Four knives, 9/16 inch, supplied with each
machine.
Bobbin winder NOT furnished with machine
unless specifically requested.
When assembled to Automatic Sequential
Unit, complete assembly is known as Machine
256-5.
o
From the library of: Superior Sewing Machine & Supply LLC

r\
BELT
Use Machine Driving Belt (endless) 2T\19I,
furnished with machine.
Overtightening of belt may cause binding of
machine, due to the extended length of arm shaft
beyond casting at pulley end. Adjust height of
driving
motor to tighten belt only sufficiently
to obtain recommended machine driving speed.
DO NOT USE A LEATHER BELT. A leather
belt can become too tight, damaging arm shaft;
or too loose, causing non-uniform rotation.
Metal clipon leather belt may set up a vibration
that interferes with belt shifter.
PRIME
PRIME
Fig. 2. Oiling Requirements of
Reservoir and Left Side of Machine
ONE DROP OF OIL DAILY
PRIME
PRIME
SATURATE DAILY
PRIME
PRIME
FILL OIL
RESERVOIR
HERE
HIGH MARK
OIL
GAUGE
LOW MARK
PRIME
Fig. 3. Oiling Requirements of
Top and Right Side of Mochine
SPEED
Maximum speed of 3000 stitches per minute
is recommended for all machines of this Class,
except Machine 271K2 with a top speed of 2700
stitches per minute.
It is advisable to run a new machine at a
speed 500 stitches per minute LESS than max
imum for the first 100 hours of operation.
The maximum efficient speed for any in
dividual machine is determined by the material
being sewn, the thread in use and the particular
style of buttonhole being made.
ROTATION OF MACHINE PULLEYS
When the machine is operating, the machine
pulleys turn over to the left (as the operator
faces the machine).
LUBRICATION
UseSINCER'OIL, "TYPE A" or "TYPE
C". Use "TYPE C" OIL when on oil is de
sired which will produce minimum stain on
fabrics.
Do not use additives in sewing machine oil,
as they may cause a reduction in normal oil
flow that can result in damage to machine.
Before starting machine, the oil reservoir
beneath the sewing
hook must be filled to the
high mark on oil gauge, through oil filler hole
in
machine bed, as instructed in Fig. 2. NEVER
ALLOW OIL LEVEL TO FALL BELOW LOW
MARK ON GAUGE.
When the machine is new or has been idle
for some time, apply oil to places labeled
"PRIME" in Figs. 2 and 3.
Apply oil daily to all other oiling points as
indicated in Figs. 2 and 3. Do not apply more
than ONE DROP OF OIL to small hole indicated
above needle bar in Fig. 3. SATURATE felt in
oiI wel Is and apply oiI freely to oiI holes marked
with red dot on machine.
From the library of: Superior Sewing Machine & Supply LLC

REGULATING OIL FLOW TO HOOK
Sewing hook is automatically lubricated.
Flow of oil to hook is regulated by screw in
bobbin
case opener bracket, as shown in Fig. 4.
IMPORTANT: Screw in center of back of
hook base is an oil metering screw, with a set
aperture. It should be tight. DO NOT DISTURB
THIS SCREW.
To determine whether oil is flowing correctly
to hook, run machine approximately one minute
to
establish auniform rate of flow. Stop ma
chine. Hold a piece of white paper underneath
hook and run machine for five buttonhole cycles.
Acorrect pattern will show five distinct oil
stains for five buttonholes.
If oil pattern is incorrect, turn the regulating
screw as required to cause it to protrude 1/8
inch beyond face of bracket as astarting point.
Test for oil pattern again and regulate when
necessary as instructed in Fig. 4. After each
separate adjustment run at least 15 buttonhole
cycles before rechecking oiI pattern.
CLEANING
Using a short bristled brush (not point of
scissors or other sharp instrument),
remove
lint or other waste from around sewing hook,
knife and work clamp and between moving ports
on underside of needle plate.
Wipe all excess oil from exterior surfaces of
machine, especially from areas that may come
in contact with fabric.
NEEDLE
Use SINGER* Needle, Catalogue 1526
(71xlY).
Selection of needle can make a great differ
ence in the ease and quality of the work. It is
important that needle be just right for specific
machine, thread and material In use and for
work being performed. The correct size will
permit thread to pass freely through needle
eye, avoiding strain, fraying and breakage of
thread. Use the smallest possible needle for
thread in use.
MORE
OIL
ir^sr
Fig. 4. Regulating Oil Flow
LOOSEN SCREW
INSERT NEEDLE UP
AS FAR AS POSSIBLE
WITH
LONG GROOVE
TO REAR: THEN
TIGHTEN SCREW
Fig. 5. Setting the Needle
Needles of Catalogue 1526 are available in
Sizes 9 to 14, 16 to 19, 21, 22 and 23.
Orders for needles must specify Quantity
required. Size number and Catalog number. For
example ---
"100 Size 13, Catalog 1526 needles"
For best results always use SINGER
needles.
NEEDLE SETTING
Loosen screw in lower end of needle bar.
Insert needle up into needle bar as far as pos
sible with long groove of needle toward rear
(facing knife) and needle eye directly in line
with arm of machine. Then tighten screw.
From the library of: Superior Sewing Machine & Supply LLC

BYPASSTHIS TENSION ^
WHEN MAKING WHIPSTITCH M
THREADS
NEEDLE-
FROM BACK
TO FRONT
271K2
Fig. 6. Threading the Needle Thread
NEEDLE THREAD
FOR THREADING
DETAILS SEE FIG. 6
NEEDLE
THREAD
TOP
CORD
TOP
CORD
TENSION
CONTROL
Fig. 7. Threading the Top Cord on Machine 271K4
THREAD
Thread recommended: 40-6cord right
twist for needle. Either left or right
twist for bobbin.
THREADING
THE NEEDLE THREAD: Pass thread
from unwinder down through thread ten
sion guide on top of
arm and through
threading points as shown in Fig. 6.
Pass thread from rear to front through
needle eye as shown in Fig. 6. Draw
about two inches of thread through
needle eye to start the stitching.
Whipstitch Buttonhole: By-pass middle tension
device on machine arm, as instructed in Fig. 6.
On machine designed primarily for whip
stitch buttonholes, such as Machine 271K4,
this middle tension device has been removed.
TOP CORD ON MACHINE 271K4: Pass cord
from unwinder into wire guide on right side of
machine head and down through threading points
shown in Fig. 7.
Draw about one inch of cord down through
hole in end of cord finger to start the stitching.
From the library of: Superior Sewing Machine & Supply LLC

BOBBIN REMOVAL
Reach beneath machine bed with thumb and
forefinger of left hand and remove bobbin case
cop and bobbin, as instructed in Figs. 8 and 9.
1. OPEN
LATCH
2. HOLD LATCH
AND PULL CASE
FROM HOOK
Fig. 8. Removing
Bobbin Case Cop from
Sewing Hook
When latch is held open, bobbin is retained
in bobbin case cop.
BOBBIN WINDING
1. THREAD THE
TENSION CONTROL^
2, PLACE BOBBIN
ON SPINDLE AS
FAR AS POSSIBLl
3. WIND THREAD
AROUND BOBBIN
Fig. 10. Bobbin Winding
3. RELEASE
LATCH
4. BOBBIN
DROPS OUT
Fig. 9. Removing Bobbin
from Bobbin Case Cap
LOOSEN TO
ADJUST FOR
EVEN WINDING
4. PUSH LEVER IN
TO BRING PULLEY IN
CONTACT WITH BELT
5. START MACHINE
When sufficient thread is wound upon bobbin,
bobbin winder will stop automatically.
Bobbins con be wound while machine is
stitching.
THREADING AND REPLACING
BOBBIN CASE CAP
SLOT NEAR TOP
Fig. 11. Replacing Bobbin in Bobbin Cose Cop
1. PULL
THREAD
INTO
LOWER
SLOT
Fig. 12
3. GRASP LOOP
OF THREAD
ABOVE
SPRING
DRAW
THREAD
UP
UNDER
SPRING
4.
PULL THREAD INTO
MIDDLE SLOT: THEN
DRAW UP AND SLIP
INTO UPPER SLOT
Fig. 13
Threading Middle and Upper Slots
5. RELEASE
LOOP OF
THREAD
6. DRAW THREAD
TAUT BETWEEN
.UPPER,
MIDDLE
lAND
LOWER SLOTS
Fig. 14. Complete the Threading of
Bobbin Case Cap
1. REPLACE BOBBIN
CASE CAP ON STUD
2. RELEASE
LATCH
3. PRESS BACK
UNTIL LATCH CATCHES
GROOVE IN STUD
\:r7
Fig. 15. Replacing Threaded Bobbin Cose Cap
Draw about two inches of thread from bobbin
to start the stitching.
o
From the library of: Superior Sewing Machine & Supply LLC

BOBBIN THREAD
MORE TENSION
LESS TENSION
Fig. 16. Regulating Bobbin
Thread Tension
more tension
LESS tension
.MORE tension
LESS TENSION
Fig. 17. Regulating Needle
Thread Tension
MORE
TENSION
TENSION
1.PULL FORWARD ON HAND RATCHET
LEVER REPEATEDLY
2. OPERATE MACHINE AT HALF SPEED
Fig. 18. Operating Hand-Ratchet
FULL SPEED
HALF SPEED
SHIFTER
'^FULL SPEED
HALF SPEED
Fig. 19. Two-Speed Belt Shifter
THREAD TENSIONS
Tension on threads should be AS LIGHT AS
POSSIBLE, while still sufficient to set stitches
correctly in buttonhole.
Regulatethe tensions, as instructed in Figs.
16 and 17.
Tension on needle thread, at all three points
shown in Fig. 17, should be uniform and equal
to tension on bobbin thread.
PURLSTITCH: Needle thread tension should
be strong enough to draw purl evenly to top
side of buttonhole.
WHIPSTITCH: Do not pass thread through
middle tension device.
PLACING FABRIC UNDER CLAMP
Depress clamp lifting treadle to raise clamp.
Position fabric under clamp so that desired
location of end of buttonhole nearest you is
directly beneath needle. Release clamp. Start
machine.
COMPLETING AN UNFINISHED
BUTTONHOLE AFTER RE-THREADING
If thread breaks or bobbin becomes empty
before completing a buttonhole, re-thread ma
chine as required and pull hand ratchet lever
forward repeatedly, as shown in Fig. 18, until
unfinished buttonhole is at desired position to
resume sewing.
Operate machine at half speed, as instructed
in Fig. 19, until this buttonhole is finished.
THE TWO-SPEED BELT SHIFTER
The two-speed belt shifter regulator per
mits operation of machine at half speed when
ever desired. Half speed is especially recom
mended when repairing unfinished buttonholes.
To operate at half speed, pull lever, shown
in Fig. 19, outward as far as possible and start
the machine.
To return to normal speed, push lever in
as far as possible, as instructed in Fig. 19.
From the library of: Superior Sewing Machine & Supply LLC

STITCHING OVER TWICE ON THE
SAME BUTTONHOLE
When it is desired to stitch over a button
hole twice for added strength (Mochine 271K4),
or for any other reason, pull
forward on knife
bar disengaging lever screw stud, Fig. 20, dur
ing first buttonhole cycle and hold this position
until cycle is completed. Release knife bar dis
engaging lever screw stud and start machine for
second cycle.
LENGTH OF BUTTONHOLE
The gauge, shown in Fig. 21, is marked
with numbers corresponding to different lengths
of buttonholes that con be made on these ma
chines.
To regulate length of buttonhole, remove
oil guard and loosen nut on regulator lever as
instructed in Fig. 21.
Place gauge in slideway
so that number
on gauge corresponding to de
sired length of buttonhole
is opposite the line
cut in the slideway, as shown. Move lever un
til sleeve under nut rests against downward
projection of gauge. Tighten nut. Replace oil
guard.
WIDTH OF BIGHT
The width of bight is determined by position
of the stud in the slotted
link, shown in Fig. 22.
To change the width of bight, open the arm
top cover and loosen the nut, shown in Fig. 22.
Move stud toward left to increase bight ortoward
right to decrease bight.
When desired width of
bight is obtained, tighten nut and close arm top
cover.
10
SCREW STUD
KNIFE BAR DISENGAGING
LEVER
Fig. 20. Knife Bar Disengaging
Lever Screw Stud
1. REMOVE
OIL GUARD
2. PLACE GAUGE'5
IN SLIDEWAY
4. PLACE
DESIRED LENGTH
OF BUTTONHOLE
ON THIS LINE
^ '3. LOOSEN
TO ADJUST
5. MOVE LEVER
UNTIL SLEEVE
RESTS AGAINST
GAUGE
6. TIGHTEN
NUT AND REPLACE
OIL GUARD
Fig. 21. Regulating Length
of Buttonhole
STUD
LOOSEN
TO ADJUST
MORE BIGHT
'T
LESS BIGHT
I'M —
^ ' 1
Fig. 22. Reguloting Width of Bight
From the library of: Superior Sewing Machine & Supply LLC

angular cut
r Jj MUST NOT BREAK ^
/V\ into TAPPED HOL^
/
C
Fig. 23. Needle Thread Handling Parts
CT
INSIDE
EDGE
THREAD CHECK
BRACKET
BOTH EDGES
OF ARM
CASTING
I
OUTSIDE
EDGE
/
CAP MUST BE
X AWAY FROM
CASTING
O "*
THREAD CHECK CAP
Fig. 24. Critical Areas on Face Plate
INTERMEDIATE GEAR
FEED WHEEL
GEAR
13- rm
FEED WHEEL
DRIVING SHAFT
!Jih
FEED WHEEL
DRIVING SHAFT GEAR
\ 'N- •
TO INSURE MATING; MARK THESE
-GEARS AT "STOP" POSITION
BEFORE REMOVAL
Fig. 25. Feed Wheel Gears
beneath Machine Bed
THREAD BREAKING OR FRAYING
Check first for these common causes ---
*Tensions too tight
* Improper threading
* Needle bent or damaged (blunt point or
burrs)
*Clogged needle eye or groove
★Thread too coarse for size of needle
* Needle incorrectly set in needle bar
Carefully examine all needle thread handling
parts. Areas where thread comes in contact
with machine are shown in Figs. 23 and 24.
These areas must be smooth and free from
burrs or sharp edges. This is extremely critical
when forming a purl stitch.
The amount of needle thread required to
pull up bobbin thread in
forming a good purl,
places an abnormal strain on needle thread.
Because of the small amount of needle thread
used in forming each stitch a certain portion
of needle thread passes bock and forth through
several thread handling parts more often than
on other lockstitch machines. This greatly in
creases the possibility of breakage, unless oil
parts in contact with thread are given more than
normal core.
When checking the areas shown in Figs.23
and 24, replace all parts
beyond repair with
new Si NC ER*parts. Clean hook oil reservoir,
removing all lint and foreign matter that has
accumulated.
Binding within the gear train (see Figs. 25
and 26) is another possible cause of thread
breakoge. Movement of oil parts must be abso
lutely free--- without hesitation or binds of
any kind.
If a bind is not easily discovered, remove
one of the stitch regulating gears, after marking
its location in "stop" position, as shown in
Fig. 26, .page 12. Rotate arm shaft to check
freeness of upper port of mechanism. Turn feed
wheel driving shaft to check lower part of
ma
chine. After bind is discovered and corrected,
replace stitch regulating gear, matching the
previously made location marks.
To reduce uneven or hesitant rotation, it may
be necessary to wire-brush and buff one or more
of the following gears - - •
Feed wheel geor
Feed wheel driving shaft geor
Feed wheel driving shaft gear
(intermediote)
Feed-ratchet geor (upper)
Feed-rotchet gear (lower)
Feed driving geor
located
belaw machine bed.
(See Fig. 25)
located
beneath orm top cover
(See Fig. 26, page 12)
11
From the library of: Superior Sewing Machine & Supply LLC

NUMBER OF STITCHES IN BUTTONHOLE
{See Fig. 26)
The number of stitches in a buttonhole is
controlled by the set of stitch regulating gears
selected for use.
IMPORTANT: To avoid disturbingthe timing
of the machine, do not permit any of the gear
shafts to turn, while changing stitch regulating
gears.
To change the stitch regulating gears, move
retainer, shown in Fig. 27, out of way and re
move each stitch regulating gear by lifting it
off its shaft. Select the desired set of gears
from chart on page 13, noting, that for a finer
range of stitching, upper feed-ratchet gear and
feed driving gear may also require changing.
To change upper feed-ratchet gear, remove
cap screw, retainer, spring and washer, shown
in Fig. 27 and lift out gear. Select correct upper
feed-ratchet gear, as listed in chart on page 13.
Place this gear
upon its shaft and replace
washer, spring, retainer and cap screw in that
order.
To change feed driving gear, loosen its
eccentric stud socket screw, shown in Fig. 27.
Remove eccentric stud. Gear will slide side-
wise and out. Replace with selected gear. Re
place eccentric stud and tighten socket screw.
Replace the selected stitch regulating gears
on their correct shafts, as listed in chart on
page 13. Make certain that slot on bottom hub
of each gear engages
its corresponding lug on
gear seat.
The eccentric studs, serving as gear shafts
for feed-ratchet gears and feed driving gear,
permit the resetting of the spacing between the
gear teeth,
whenever gears are changed. These
studs, shown in Fig. 26, ore identified by the
screwdriver slot on top end. To adjust, loosen
the eccentric stud socket screws, shown in Fig.
27. Turn eccentric studs as required to avoid
possible binding or unnecessary play. Securely
tighten socket screws.
12
TIMING MARK UP
STOP CAM
HOOK DRIVING
CONNECTION
BELT PULLEYJ
GEAR
FEED DRIVING
BEVEL PINION
FEED DRIVING q
BEVEL GEAR
FEED
DRIVING
PINION
STITCH
REGULATING
GEARS
\ DRIVING
driven!
/
FEED
DRIVING
GEAR
eccentric
STUDS
FEED
ratchet
gears;
UPPER
lower
NEEDLE BAR FRAME
DRIVING GEAR
Fig. 26. Gear Train at 'Stop' Position
ECCENTRIC
STUD
WASHER
UPPER FEED
RATCHET GEAR
SCREW ECCENTRIC
SPRING
STUD
SOCKET
SCREWS
LUG
FEED
DRIVING GEAR
Fig. 27. Changing Feed Driving Gears
From the library of: Superior Sewing Machine & Supply LLC

GEAR SELECTION CHART
STITCH REGULATING GEARS NUMBER OF STITCHES (Needle Dips)
OBTAINED IN BUTTONHOLE FOR EACH
REVOLUTION OF FEED WHEEL
USED AS
USED AS
USING FEED-DRIVING
USING FEED-DRIVING
DRIVEN
DRIVING GEAR 271550 (64 teeth)
GEAR 271854 (72 teeth)
GEAR GEAR
WITH UPPER FEED- WITH UPPER FEED-
RATCHET GEAR 271559
RATCHET GEAR 271855
(32 teeth)
(24 teeth)
PART
NUMBER
Number
of
T eeth
PART
NUMBER
Number
of
Teeth
MEDIUM RANGE
(Regularly Supplied in
Mochines 271K1,271K4
and 271K201)
FINE RANGE
(Regulorly Supplied in
Machines 271 K2 and
271K3)
271646
60
271634
30 240
360
271648
60 271637 36 200
300
271645
54
271636
36
180 270
271642
48 271638 36
160
240
271644*
50 271639* 40
150
—
271643®
48 271640® 40 144
216©
271459®
44
271458®
40 132 198
271641®
45
271641®
45
120®
180
271640® 40
271643®
48 100®
150
271639®
40
271644©
50 96 144©
271638*
36 271642* 48
90
—
271636
36 271645
54
80
120
271637
36
271648
60
72
108
271635®
32
27 16 47® 60 64
96
271634 30
271646 60 60
90
OnOT REVERSIBLE: Reversing this set of
gears mo/ cause needle'to stop on wrong side
alternately or at odd intervals.
*These gears can be used in locations listed,
only when machine is fitted with medium range
feed driving gear 271550 and feed-ratchet gear
271559.
© Regular for Machines 271K1 and 271K201
0 Regular for Machine 271K2 (NOT REVERSIBLE)
0 Regular for Machine 271K3
0 Regular for Machine 271K4.
See instructions on page 12 for method of changing
these gears.
13
From the library of: Superior Sewing Machine & Supply LLC

PRE-TENSION CONTROL
Since the tension on the needle thread ac
tuated by the middle tension device, shown in
Fig. 28, is released during bar stitching, the
pre-tension control is of primary importance
during this portion of the sewing cycle.
Tension on needle thread due to pre-tension
control should be just enough to prevent sewing
hook from stealing thread, at this time. Adjust
this tension by turning knurled nut on pre-ten
sion control, OS shown in Fig. 28, so that even
the first three or four stitches immediately
followingthe bar stitchingpull up into an attrac
tive purlstitch. Too light tension causes these
stitches to be loose or to look similar to whip
stitches. Too heavy tension may break thread.
See "SPECIAL INSTRUCTIONS FOR MACHINE
271K2", starting on page 33.
NEEDLE THREAD TAKE-UP SPRING
The tension on take-up spring, shown in
Fig. 29, during
downward stroke of needle,
should be sufficient to take
up slack of thread
until eye of needle reaches the material.
To adjust, loosen take-up spring set screw
and turn ONLY the tension stud, as instructed
in Fig. 29. Then securely tighten set screw.
TOP CORD FINGER ON MACHINE 271K4
HEIGHT SETTING: Cord finger, shown in
Fig. 30, should just clear top surface of clamp
check, during movement of finger
from right
side to front of needle and return.
To adjust, loosen screw, shown in Fig. 30.
Raise or lower finger, as required.
SECURELY
tighten screw.
14
MORE TENSION
PRE-TENSION
CONTROL
BAR
RIGHT WRONG
MIDDLE
.^l'ess tension /SivfcE'^
TENSION
RELEASEDI
DURING
BAR STITCHING
Fig. 28. Regulating Pre-Tension
-aii
TURN STUD
LESS TENS ON
,11
MORE TENSION
TAKE-UP
SPRING
AT REST
LOOSEN
TO ADJUST
Fig. 29. Adjusting the Talce-up Spring
CLEARANCE-^
LOOSEN TO ADJUST
HEIGHT OF
CORD FINGER
CLAMP CHECK
Fig. 30. Cord Finger at Correct Height
on Machine 271K4
r\
From the library of: Superior Sewing Machine & Supply LLC

CORD ROTATING
TRIPPING CAM
CAM
SET SCREWS
CORD ROTATING
SECTOR
CORD
FINGER
Fig. 31. Timing the Cord Finger
LOOSEN
LOCK NUT
CORD FINGERI
IN FRONT OF
NEEDLE
FRONT
msnz.
TURN SCREW
TO
ADJUST
TRIPPING
LATCH
ADJUSTABLE
CATCH
CORD ROTATING
SECTOR
Fig. 32. Adjusting the Tripping Latch
LOOSEN
SCREW
TO ADJUST CATCH
CORD
ROTATING
SECTOR
Fig. 33. Setting the Adjustable Catch
TOP CORD FINGER ON MACHINE 271K4
(continued)
TIMING: The cord rotating tripping cam, shown
in Fig. 31, should
actuate the cord finger at
next to the lost stitch in the first bar andagamot
the end of the sewing cycle. When the barring
at the far end of the buttonhole is nearly finished,
finger should swing to position in front of needle
as shown in Fig. 32, and remain there until
buttonhole is finished. Finger should then return
to
its starting position at right of needle, shown
in Fig. 33.
To time cord rotating tripping cam, loosen
the two set screws, shown in Fig. 31, in hub of
cam and turn
cam on its upright shaft, as re
quired. Then securely tighten cam set screws.
TRIPPING LATCH FUNCTION: The cord finger
tripping latch,
shown in Fig. 32, should hold
cord rotating sector in position (keeping finger
in
front of needle) while machine is stitching
entire right side of buttonhole.
To adjust, loosen lock nut, shown in Fig. 32,
and turn latch screw as required. Then securely
tighten lock nut.
ADJUSTABLE CATCH FUNCTION: The ad
justable catch, located on underside of sector,
must accept tripping latch as
shown in Fig. 32,
at next to last stitch in first bar.
To adjust, loosen screw, shown in Fig. 33
immediately behind adjustable catch, and move
catch as required. Then securely tighten screw.
15
From the library of: Superior Sewing Machine & Supply LLC

THE CUTTING SPACE
The amount of cutting space between the
lines of stitching in a buttonhole is determined
by the position of the regulator (shown in Fig.
34) on the clomp carrier slide lever.
To adjust, loosen the large screw, visible in
the slot in the mochine bed (see Fig. 34) and
move the regulator toward rear of slot for wider
cutting space or toward front of slot for narrower
cutting space. Then securely re-tighten screw.
NEEDLE AND KNIFE ALIGNMENT
The left and right sides of a buttonhole
should ALWAYS be stitched at an equal distance
from the knife. Knife will then cut the button
hole in the exact center, avoiding damage to the
stitches on either side.
This is achieved by positioning the needle
correctly in relation to the knife. To align the
needle with the knife, loosen the two screws,
shown in Fig. 35, in the needle bar frame pitman
and move the pitman, needle bar frame and
needle, as required. When correctly set, needle
(on
its right-hand throw) will align with center
of knife
slit in needle plate, as shown in Fig.
35. Securely retighten pitman fastening screws.
KNIFE REPLACEMENT
When a new knife is required, remove knife
fastening screw and washer,
shown in Fig. 36
and remove old knife. Place new knife in holder,
pushing it upward in holder
recess as for as it
will go and fasten it with screw and washer.
Before tightening screw securely, moke certain
that front edge of knife, when cutting, will
reach 1/16 inch below top surface of needle
plate. If knife does not moke full cut, it should
be
set slightly lower, but never low enough to
strike the hook. Keep knife sharp to ensure
clean-cut buttonholes.
16
WIDER
LOOSEN SCREW
TO ADJUST
MOVE REGULATOR %
TO CHANGE
CUTTING SPACE - ^
NARROWER
CLAMP CARRIER
-SLIDE LEVER
Fig. 34. Regulating Cutting Spoce
to MOVE NEEDLE
^TOWARD LEFT
'H !
LOOSEN SCREWS
TO ADJUST
PITMAN
TO MOVE NEEDLE
i TOWARD RIGHT
NEEDLE ALIGNED
WITH CENTER OF
KNIFE SLIT IN
NEEDLE PLATE
NEEDLE BAR
!!/ FRAME
ON RIGHT-HAND
THROW
Fig. 35. Aligning Needle with Knife
TOP SURFACE
OF NEEDLE PLATE
1 \
1/16" front EDGE
OF KNIFE
Fig. 36. Setting the Knife
SCREW
WASHER
From the library of: Superior Sewing Machine & Supply LLC

KNIFE BAR STOP
/^ll
CONNECTlNGnTAP LIGHTLY
LINK ^init^r^UPON DRIVING
./>-—LEVER
A SLIGHT ^
CLEARANCE
STARTING^'^^
LEVER IN nl.
"RUN" POSITION
CONNECTING
STUD
APPROX. 1/64"
CLEARANCE
I
KNIFE BAR
UP
KNIFE
Fig. 37. Knife Bar at Correct Height
REACH KNIFE
BAR CLAMPING
SCREW THRU
THIS HOLE
Fig. 38. Ad|usting Knife Bar Height
LOOSEN
TO ADJUST ^11 O'CLOCK
r-.>;^POSITION
DRIVING
LEVER
AUTOMATIC
KNIFE DISENGAGING
LEVER IN CONTROL
KNIFE BAR
SPRING ARM
Fig. 39. Adjust Knife Bar Spring Tension
KNIFE BAR HEIGHT
When knife bar is at correct height, as shown
in Fig. 37, there will be only a slight clearance
(o small amount of play) between knife bar con*
necting stud and top of slot inside knife bar
connecting link. This setting is necessary to
insure approximately
1/64 inch clearance (in
side knife bar stop) between top of knife bar
and inside-top of knife bar stop, so that knife
bar will not rap against knife bar stop on its
return stroke, after cutting buttonhole. During
adjustment, starting lever must be at "run"
position (knife bar up), as shown in Fig. 37.
Loosen knife bar clamping screw, as instructed
in Fig. 38.
With knife bar in its highest posi
tion, press down on forward end of driving lever,
Fig. 37, forcing connecting stud at rear end of
driving lever to bear against top end of
slot in
connecting link. Tighten clamping screw just
enough to hold knife bar in position. Tap lightly
upon REAR END of driving lever, as instructed
in Fig. 37, until there is a slight clearance
between stud and link. Then securely tighten
knife bar clamping screw.
DRIVING LEVER SPRING TENSION
Tension on the knife bar driving lever spring,
shown in Fig. 39, should be just sufficient to
hold knife bar at its highest position, whenever
thread breakage occurs and automatic knife
disengaging lever goes into operation.
Excessive tension on this spring may cause
knife bar to break knife bar stop on its return
stroke.
To adjust, loosen hex-head screw, shown in
Fig. 39. Set spring arm at 11 o'clock position.
Tighten hex-head screw. Hook spring arm under
driving lever, as shown.
17
From the library of: Superior Sewing Machine & Supply LLC

KNIFE GRINDER 701W51
Grinder 701W51 should be set to turn awoy
from knife at a speed of approximately 2500
revolutions per minute.
To sharpen the knife, remove it from machine
and clamp it in knife holder as shown in Fig. 40.
Firmly tighten clamping screw.
Position of pointer on turret should be de
termined by length of knife edge - - -
For all knives up to and including 3/4 inch
in length, use position
**B" on turret (see Fig.
40).For all knives 13/16 inch and longer, use
position "A" on turret (see Fig. 40).
To set knife at correct angle to grinder,
loosen turret screw end move turret until pointer
is at correct position, as instructed above, and
tighten turret screw securely.
Start grinder and turn adjusting screw, shown
in Fig. 40, to bring knife into position where
grinding
wheel will barely graze the cutting
edge of the knife.
To grind knife,
move slide bracket once to
the right and once to the left.The least possible
amount ground off is usually sufficient. If more
than a slight amount of the knife edge is ground
off at one movement, temper of knife may be
damaged permanently.
Having sharpened one side of knife, loosen
stop screw, shown in Fig. 40. Set knife stop
against lower end of knife in holder and secure
ly tighten stop screw. Loosen clamping screw
and remove knife, returning it to knife holder
with unshorpened side down. See that knife is
held securely against knife stop and securely
tighten clamping screw. Loosen turret screw and
move turret until pointer is at same letter des
ignation at other end of turret. For example - - -
if turret was set
with pointer at one "A" posi
tion, turret should be moved until pointer is at
the other
"A" position. When turret is set cor
rectly, tighten turret screw securely. Proceed
with grinding this side of knife in same manner
as first side was ground.
When knife is held correctly and turret is
properly set, the desired bevel is assured and
the knife can be sharpened equally on both
18
4" (EMERY)
GRINDING
WHEEL
COVER
CLAMPING
SCREW
KNIFE
TURRET
SCREW
POINTER
SET POINTER AT
"B" FOR KNIVES
UP TO AND INCLUDING
3/4 INCH IN LENGTH
KNIFE
HOLDER
ADJUSTING
SCREW
FE STOP
STOP SCREW
SLIDE
BRACKET
TURRET
SET POINTER
AT "A" FOR KNIVES
13/16 INCH AND LONGER
Fig. 40. Sharpening the Knife
sides with its cutting edge in the center of the
thickness of its blade.
When knife is correctly ground remove it
from grinder and carefully rub knife edges just
a little on an oi 1 stone.
OILING: Push aside cover shown in Fig. 40
and apply oil to the two holes thus uncovered.
The following knives are regularly furnished
for these machines - - -
MACHINE
KNIFE
NUMBER
LENGTH
(INCHES)
GRINDING
POSITION
OF
TURRET
271K1
271903 5/8 B
271K2 271901 1/2 B
271K3
39558
1-1/2
A
271K4 39829 3/4 B
271K201
271902
9/16
B
Knives from 3/8 inch to 1-1/2 inches in
length are available upon specific order.
From the library of: Superior Sewing Machine & Supply LLC

TIMING MARK (
STOP
CAM
LOOSEN
TO ADJUST
MORE
TENSION
PINION
TURN
ECCENTR C
STUD
CLOCKWISE
STOP NOTCH
INTERLOCKING
ROD
^•^LESS
TENSION
Fig. 41. Interlocking Rod and
"Stop" Position Notch
STOP CAM
GEAR
LOOSEN SET SCREW
TO ADJUST
HIGH POINT OF STUD
AT 6 O'CLOCK
Fig. 42. Stop Cam Gear and Pinion
HIGH POINT
CAM
Fig. 43. High Point of Stop Cam
STOP MOTION
To ensure a positive stop and to minimize
the possibility of breakage of parts, a two-
speed drive mechanism automatically slows
down arm shaft to one-half driving speed as
machine approaches
"stop" position. A stop
cam driven at half speed of arm shaft (now 1/4
of operating speed, to reduce strain as machine
goes into "stop") is now engaged by the stop
motion interlocking rod.
Stop motion interlocking rod, shown In Fig.
41, is designed to aid in retarding speed of
arm shaft before finally stopping machine.
TENSION ON INTERLOCKING ROD should
be only sufficient to prevent rod from jumping
cut of notch, shown in Fig. 41, in stop cam.
When making buttonholes on heavy fabrics
it may become necessary to lighten the tension
on interlocking rod. Light weight fabrics usually
require aheavier tension.
To
adjust, loosen lock nut and turn thumb
screw at lower end of rod as instructed in Fig.
41. Tighten lock nut.
EXCESSIVE PLAY BETWEEN STOP CAM
GEAR AND PINION should be eliminated.
To adjust, loosen set screw shown in Fig.
42 and turn eccentric stud clockwise (facing
rear of machine) as shown, until
minimum play,
without binding between teeth of gears, is
obtained. Turning the stud clockwise will draw
stop cam closer to interlocking rod (rather
than away
from it) making certain that rod will
ride on high point, of stop cam, as shown in
Fig. 43, before dropping into "stop" position
notch, as shown in Fig. 41.
When minimum play between gears is a-
chieved, high point of eccentric stud should be
at bottom (approximately at 6 o'clock position),
as shown in Fig. 42. Never moke this setting
with high point of stud on top, as this may
allow interlocking rod to enter stop cam notch
without first riding on high point of stop cam.
19
From the library of: Superior Sewing Machine & Supply LLC

STOP MOTION
(continued)
CLEARANCE BETWEEN INTERLOCKING
ROD GUIDE AND LOCK PIN when rod has
tripped and is riding on high point of stop cam,
as shown in Fig. 44, should be approximately
1/16 inch, as shown in Fig. 45.
This clearance will permit rod guide to
raise lock pin and correctly activate tension
releaser shaft crank, shown in Fig. 46, and
safety tripping lever lock, when machine reaches
stop position.
To adjust, loosen lock nut, shown in Fig.
47, and turn adjusting-screw in tension releaser
lever downward to increase clearance or up
ward to
decrease clearance, as required. Se
curely retighten lock nut.
CLEARANCE BETWEEN STOP CAM FACE
AND INTERLOCKING ROD, when machine is
in stop position, as shown in Fig. 48, should
be approximately .015 inch.
This clearance will prevent interlocking
rod from striking stop cam.
To adjust, loosen lock nut shown in Fig.
48, on lower end of starting lever, and turn stop
screw inward to increase clearance or outward
to decrease clearance, as instructed in Fig. 48.
Securely re-tighten lock nut.
REPLACEMENT OF STOP CAM GEAR SPRING
If stop cam gear spring (enclosed in stop
cam gear) breaks, it can be
removed and a new
spring inserted, as follows (see Figs. 49 and 50).
1. Remove wick, shown in Fig. 49, from
eccentric stud.
2. Observe timing marks on matched tooth
and groove on pinion and stop com gear,
as shown in inset in Fig. 50, then loosen
eccentric stud set screw.
20
STOP CAM
INTERLOCKING
ROD
HIGH POINT
Fig. 44. Interlocking Rod
has Tripped and is on
High
Point of Stop Cam
LOCK PIN
llf;®
a
CLEARANCE
ROD GUIDE
Fig. 45. Clearance of
Lock Pin above Rod Guide
,, TENSION
^RELEASER
TENSION
RELEASER
SHAFT CRANK
Fig. 46. Tension Releaser Shaft Crank
SHAFT
QLOOSEN LOCK NUT
TO ADJUST,
II f
TURN SCREW,
DOWN F0R'/,\2p^
MORE
CLEARANCE "
Fig. 47. Adjusting Lock Pin Clearance
TENSION
' \releaser
LEVER
From the library of: Superior Sewing Machine & Supply LLC