Singer 251 -1, 251 -2, 251 -3 sewing machine Service manual

SINGER
CLASS 251
USE SINGER" OILS
and LUBRICANTS
They insure freedom from lubricating trouble and give
longer life to sewing equipment
The following are the correct lubricants for the
241, 251, 253, 400w, 402w and 410w Machines:
TYPE A — MANUFACTURING MACHINE OIL, LIGHT GRADE
When an oil is desired which will produce a minimum of
stain on fabrics, even after a long period of storage, use:
TYPE C — MANUFACTURING MACHINE OIL, LIGHT GRADE
OTHER SINCER LUBRICANTS
TYPE E — THREAD LUBRICANT
For lubricating the needle thread of sewing machines for
stitching fabrics or leather where a thread lubricant is
required.
TYPE F — MOTOR OIL
For oil lubricated motors and plain bearings in power
tables and transmitters.
NOTE: All of the above oils are available in 1 quart,
1 gallon and § gallon cans.
BALL BEARING LUBRICANT
This pure grease is specially designed for the lubrication
of ball bearings and ball thrust bearings of motors and
electric transmitters, ball bearing hangers of power tables,
etc. Furnished in 1 Ib. and 4 Ib. tins.
E 0 т ео
20549
SERVICE MANUAL
FOR
SINGER
SEWING MACHINES
CLASS 251
SINGLE NEEDLE LOCK STITCH
AUTOMATIC OILING SYSTEM
н в
EZ4BAS
CAUTION — See that the oil reservoir is filled as instructed on page 5
before running the machine, even to test the speed.
THE SINGER MANUFACTURING COMPANY
"A Trade Mark of THE SINGER MANUFACTURING COMPANY
Copyright (0) 1955, by The Singer Manufacturing Company
3
DESCRIPTION
Machines of Class 251 are high speed, single needle, lock stitch
machines with a completely automatic lubricating system. They have
a gear driven, lubricated, rotary sewing hook on a horizontal axis
and a drop feed.
The rotary sewing hook makes two revolutions for each stitch.
The bed of these machines is 18-3/4 inches long and 7 inches
wide. The space at the right of the needle is 11 inches. The machine
base and oil reservoir furnished with these machines will fit any table
cut-out provided for Machines of Classes 31-, 96- and 241-.
A centrifugal oil pump delivers oil, under pressure, to all the prin-
cipal bearings. Provision is also made to automatically lubricate all
the other bearings in the machine.
The needle thread take-up lever is covered by an oil guard to pre-
vent splashing of excess oil.
An oil flow window, in direct view of the operator, indicates the
circulation of oil inside the arm of the machine.
The machine pulley furnished is for a 3/8 inch V-belt. It can be
used for a 5/16 inch round belt, when desired.
These machines are furnished with a knee lifter, which is an in-
tegral part of the machine base and oil reservoir.
Machine 251-1 has a needle bar stroke of 1-9/64 inches and a
presser bar lift of 9/32 inch; can sew a maximum of 7 stitches to the
inch and is designed for sewing light weight fabrics.
Machine 251-2 has a needle bar stroke of 1-13/64 inches and
a presser bar lift of 5/16 inch; can sew a maximum of 5-1/2 stitches
to the inch on medium-heavy to light weight} fabrics.
Machine 251-3 has a needle bar stroke of 1-7/16 inches and a
presser bar lift of 3-8 inch; can sew a maximum of 5-1/2 stitches to
the inch on heavy to light weight} fabrics. This machine can also be
furnished with a presser bar lift of 7/16 inch, enabling it to sew extra-
heavy to light weight! material,
{For best performance on light weight fabrics, it is recommended that Machines 251-2
and 251-3 be equipped with fittings designed for the particular operation.
4
SPEED
The maximum speed recommended for Machines 251-1 and 251-2 is
5000 revolutions per minute and for Machine 251-3, 4300 revolutions
per minute according to the material being sewn and the type of work
being done.
It is advisable to operate these machines at a more moderate
speed the first few days, after which they can be operated at maximum
speed.
When the machine is in operation, the top of the machine pulley
must always turn over toward the operator.
SETTING UP
When shipped, the base is held to the machine by a single bolt
through the bottom of the base. Discard this bolt and plug the hole by
inserting from inside the base, the special cap screw K, Fig. 3, fur-
nished with the machine.
The base fits into a standard
table cut-out and rests on the four
corners without fastening.
Rasp the edges of the cut-out,
if necessary, as the base must slide
in without driving and must be lo-
cated so that the machine head
does not touch the table when it is
placed on the base.
Use shims on the corners, if nec-
essary, to prevent the base from
rocking. The base should also be
level in both directions so that the
oil level will be accurately indi-
cated by the marks in the base.
See that the plunger L, Fig. 3 is in place inside the base, before
putting the machine on the base.
The machine head rests on the cork gasket in the base and is not
fastened. The machine hinges must not support the head except when
it is tilted back.
The knee lifter is shipped assembled to the base, except for the
knee plate and lever J, Fig. 2. After the base is in position, loosen the
set screws D and E, Fig. 2 and slide the shaft forward to the position
shown in Fig. 2. Attach the knee lifter lever J. Set the stop screw F so
that there is only a little play of the lifter before it starts to lift the
presser bar, then hold the screw and tighten lock nut G. Set the rear
stop dog H to allow the presser bar to be just raised to its limit but not
enough to permit further strain on the knee lifter parts or to permit the
action of the knee lifter to lift the machine from its base.
CAUTION: Before starting the machine, it must be thoroughly
oiled, in accordance with the following instructions.
Fig. 2. Installation of Knee Lifter
5
LUBRICATION
Machines of Class 251 have an automatic lubricating system in
which oil is circulated from a reservoir in the base. See X-Ray view
of machine on pages 24 and 25.
TURN BACK MACHINE
— HIGH —
= LOWWArD OIL -
Tf
K TT FILL TO
NEVER ALLOW
OIL TO FALL HIGH MARK
BELOW LOW MARK
BEFORE STARTING THE MACHINE, the oil reservoir must be filled as
instructed in Fig. 3, with “TYPE A” or “TYPE €” OIL, sold by Singer
Sewing Machine Company. For description of these oils, see inside front
cover of this book.
NOTE: Before starting a machine which has been standing idle for
several weeks, it is advisable to remove the face plate and oil the
needle bar and take-up bearings. The automatic oiling system will
lubricate these bearings after the first few minutes.
When in operation, the oil level in the reservoir should be inspected
at least twice a month, or as often as necessary, to keep it from going
below the LOW mark, see Fig. 3, in the reservoir.
Fig. 3. Oil Reservoir
The correct operation of the
lubricating system is shown by a
continuous stream of oil passing
through the oil flow window, as
shown in Fig. 4, while the machine
is running.
CAUTION
If the oil flow should stop, the
machine should be stopped and not
run again until the cause has been
determined.
See instructions, covering Oil
Removing Wick Assembly, on pages
38 to 41.
SHOULD SHOW
STEADY OIL FLOW
Fig. 4. Oil Flow Window
6
ADJUSTMENT OF ROTATING HOOK OIL FLOW REGULATOR
The sewing hook is automatically lubricated. The flow of oil is
controlled by the oil flow regulator illustrated below.
Tm 143350
140551
Fig. 5. Oil Flow Regulator in Hook Shaft Bushing
The oil flow regulator is set at the factory for automatic lubrica-
tion of the hook under average sewing conditions. If more or less oil
is desired, turn the adjusting thumb screw 140551, Fig. 5, clockwise to
increase the flow of oil to the hook, as indicated by the (+) sign
under its arrow on the head of the thumb screw, or turn it counter-
clockwise to decrease the flow, as indicated by the (—) sign under its
arrow on the head of the thumb screw 140551.
To determine whether the oil is properly flowing to the hook,
withdraw the bed slide and hold a piece of thin paper under the
hook while the machine runs for ten seconds. There should be a
slight trace of oil on the paper. If there is not, adjust the oil flow
regulator, as instructed above, or replace the oil filter 143350, Fig. 5,
in the head of the hook shaft, as instructed on page 32.
HINTS FOR PERFECT OPERATION
When in operation, the top of the machine pulley must always turn
over toward the operator,
Do not run the machine with the presser foot resting on the feed
without cloth under the presser foot.
Do not run the machine when both bobbin case and needle are
threaded unless there is material under the presser foot.
Do not try to aid the machine by pulling the fabric lest you bend
the needle. The machine feeds the work without assistance.
The slide over the bobbin case should be kept closed when the
machine is in operation.
If the sewing hook should become excessively warm, it may be
due to an insufficient supply of oil to the hook (see instructions, above,
for adjusting oil flow regulator).
NEVER TOUCH THE STITCH REGULATOR PLUNGER WHILE THE MA-
CHINE IS RUNNING.
7
NEEDLES
Needles for Machines of Class 251 are as follows:
PRESSER TYPE | NEEDLES a
MACHINE BAR OF CLASS AND
LIFT MATERIAL VARIETY SIZES
251-1 | 9/32 inch Light 88x99 |8, 9, 10, 11, 12, 13,
14, 16, 17, 18, 19,
20, 21, апа 22
8, 9, 10, 11, 12, 13,
14, 16, 17, 18, 19,
251-2 | 5/16 inch | Medium-Heavy
to Light
— . -— 16 x 257
251-3 | 3/8 inch | Heavy to Light 20, 21, 22, 23, and
Regular 24
251-3 | 7/16 inch Extra-Heavy 16 x 261 116, 18, 19, 21, 22,
to Light and 23
The above needles are regularly nickel finish but are available
with chromium finish if so ordered.
The size of the needle to be used should be determined by the size
of the thread which must pass freely through the eye of the needle.
Rough or uneven thread, or thread which passes with difficulty through
the eye of the needle, will interfere with the successful use of the
machine.
Orders for needles must specify the Quantity required, the Size
number, also the Class and Variety numbers, separated by an x.
The following is an example of an intelligible order:
“100 No. 16, 88 x ? Needles.”
The best stitching results will be obtained by using needles sold
by Singer Sewing Machine Company.
THREAD
Left twist thread should be used in the needle. Either right or left
twist thread can be used in the bobbin.
HOLD THI
>END ROLL OVER
| TOWARD YOU
# 27Ф ЛА
Fig. 6. How to Determine the Twist
To determine the twist, hold the thread as shown above. Roll the
thread over toward you between the thumb and forefinger of the
right hand; if left twist, the strands will wind tighter; if right twist,
the strands will unwind.
RELATIVE SIZES OF NEEDLES AND THREAD
The following sizes of needles and thread are recommended ac-
cording to the class of work:
SIZES SIZES OF
OF CLASSES OF WORK COTTON, LINEN
NEEDLES OR SILK
Shirtings, Sheetings, Calicoes, Muslins, 60 to 80 Cotton
14 Silks, Dress Goods and all classes of A and B Silk
general work.
16 | All kinds of heavy Calicoes, light
and Woolen Goods, heavy Silk, Seaming, C Silk
17 Stitching, etc.
Tickings, Upholstery, Woolen Goods, 30 to 40 Cotton
18 Trousers, Boys’ Clothing, Cloaks, etc. D Silk
Heavy Woolens, Tickings, Bags, Heavy 20 to 30 Cotton
19 Coats, Trousers, Heavy Clothing gener- E Silk
ally. 60 to 80 Linen
21 | Bags, Coarse Cloths and Heavy Goods. | 16 10.20 Cotton:
40 to 60 Cotton
40 to 60 Linen
TO SET THE NEEDLE
Turn the machine pulley over
toward the operator until the
needle bar moves to its highest
point.
After loosening needle set
screw, insert needle UP into
needle bar AS FAR AS IT WILL
GO, as instructed in Fig. 7.
NOTE: The needle is held in
place, in Machines 251-2 and
251-3, by means of a needle
clamp instead of by means of the
set screw in the needle bar as in
Machine 251-1, illustrated in
Fig. 7.
The single continuous groove
of the needle MUST face the left
end of the machine, as shown
in Fig 7.
Securely tighten needle set
screw.
MOVE TO
HIGHEST
POINT
¢ LOOSEN
SCREW
INSERT
NEEDLE UP
AS FAR AS
POSSIBLE
Fig. 7. Setting the Needle
(Machine 251-1)
9
UPPER THREADING
NOTE: The take-up lever oil guard should NOT be removed when
threading the machine. It is removed in Fig. 8 only to show the entire
path of the needle thread.
Pass the needle thread from the unwinder through the threading
points in the order shown in Figs. 8 and 9.
Fig. 8. Upper Threading
Fig. 9. Threading the Needle
Draw about two inches of thread through the eye of the needle
with which to commence sewing.
TO REMOVE THE BOBBIN TO WIND THE BOBBIN
vio - Ä See Fig. 13.
| | Turn the machine pulley over Fasten bobbin winder to table with its driving pulley in front of
| | toward the operator, until the the machine belt, as shown below, so that pulley will move away from
| needle thread take-up lever is at belt when sufficient thread has been wound upon the bobbin.
| its highest point as shown in
1. MOVE ~ Fig. 10.
TAKE-UP !
TO HIGHEST | Reach beneath the bed of OIL
POINT ; the machine with the left hand
| and remove the bobbin, as in-
i structed in Figs. 11 and 12. |
y | Ka
o PRESS ©
Fig. 10. Preparing for | DOWN PSV
q
Removal of Bobbin TO PUSH
| | PULLEY |
| AGAINST
BELT
| PLACE BOBBIN
| G ON SPINDLE
À
2. OPEN
LATCH
Fig. 13. Winding the Bobbin
Place bobbin on spindle, pushing it on as far as it will go and pass
thread through threading points, as shown above.
3. HOLD LATCH
AND PULL CASE Wind end of thread around the bobbin a few times. Press down
FROM HOOK on thumb latch, pushing driving pulley over against belt, as shown in
Fig. 13. Start machine.
Fig. 11. Removing Bobbin Case from Sewing Hook Bobbin winder will stop automatically, when the amount of thread
for which it is regulated is wound upon the bobbin. For more thread
NOTE: While the latch is kept 4. RELEASE on bobbin, turn screw A inward; for less thread on bobbin, turn screw
open, the bobbin will be retained IN A outward.
in the bobbin case. When winding a bobbin with fine thread, a light tension should
be used. Adjust the knurled nut X, Fig. 13, to regulate the tension.
To remove the bobbin from > | g 9
the bobbin case, release the If thread winds unevenly on bobbin, loosen screw B and move
tension bracket C to the left or right, as required. Tighten screw B.
latch, turn the open end of the 5 BOBBIN
bobbin case downward and the DROPS Bobbins can be wound while the machine is stitching.
bobbin will drop out, as shown OUT
in Fig. 12. NOTE: Occasionally apply a few drops of oil to the oil well, shown
in Fig. 13, on top of the bobbin winder frame.
Fig. 12. Removing the Bobbin
12
TO THREAD THE BOBBIN CASE
SLOT
NEAR
Hold the bobbin so that the TOP
thread will unwind in the di- Ny
rection shown in Fig. 14.
Hold the bobbin case as
shown in Fig. 14 and place the
bobbin into it.
Fig. 14. Placing Bobbin
in Bobbin Case
|
PULL
9 57 / THREAD
DRAW THREAD SLOT
UNDER SPRING and under the tension spring 2,
Fig. 15.
Fig. 15. Pulling the Thread 3. DRAW
into the Slot THREAD
Draw the thread into the delivery eye
at the end of the tension spring, as shown
in Fig. 16.
Fig. 16. Drawing the Thread
Under the Tension Spring
INTO Pull the thread into the slot 1
INTO DELIVERY
TO REPLACE THE BOBBIN
1. REPLACE BOBBIN CASE
ON STUD
2. RELEASE
LATCH
©
3. PRESS BACK
UNTIL LATCH CATCHES
GROOVE IN STUD
Fig. 17. Bobbin Case Threaded and Replaced
After threading, take bobbin case by latch in the left hand and
place bobbin case on center stud of bobbin case holder, as instructed
in Fig. 17. Release latch. Press bobbin case back until latch catches
groove near end of stud. Allow about two inches of thread to hang free.
14 15
TO PREPARE FOR SEWING TO REMOVE THE WORK
Hold slack end of needle thread loosely and turn machine pulley Let the thread take-up lever rest at its highest point.
over toward you until needle moves down and up again to its highest Raise the presser foot.
point, catching bobbin thread. Draw up needle thread; bobbin
thread will come up with it through hole in throat plate, as shown in
Fig. 18. Lay both threads back under presser foot.
Draw the work toward the rear until it is clear of the needle.
Cut the threads close to the goods.
> WN —
TENSIONS
For ordinary stitching, the needle and bobbin threads should be
locked in the center of the thickness of the material, thus:
SBE
r Fig. 19. Perfect Stitch
y If the tension on the needle thread is too tight, or if that on the
bobbin thread is too loose, the needle thread will lie straight along
the upper surface of the material, thus:
Fig. 20. Tight Needle Thread Tension
Fig. 18. Drawing Up the Bobbin Thread If the tension on the bobbin thread is too tight, or if that on the
needle thread is too loose, the bobbin thread will lie straight along
the under surface of the material, thus:
TO COMMENCE SEWING
Place material beneath the presser foot, lower the presser foot and
commence to sew, turning the machine pulley over toward you.
Fig. 21. Loose Needle Thread Tension
16
TO REGULATE THE TENSION ON THE NEEDLE THREAD
Tension on the needle
\ | thread should be regulated
only when the presser foot
is down.
| Tension on the needle
7 MORE thread should be just
TENSION enough to set the stitch
properly in the material.
A Having lowered the
presser foot, turn the thumb
LESS nut at the front of the ten-
TENSION . . . .
sion discs, as instructed in
Fig. 22.
Fig. 22. Regulating
Needie Thread Tension
TO REGULATE THE TENSION ON THE BOBBIN THREAD
When the tension
on the bobbin thread
has been once prop-
erly adjusted, a correct
stitch can usually be
obtained by varying
the tension on the
needle thread only.
MORE
For average sew- TENSION
ing the tension on the —
bobbin thread should
be very light. ©
To regulate the ten- mo N
* bin LESS
sion on the bobbi TENSION
thread, remove the
bobbin case and turn Fig. 23. Regulating
the screw in the ten- Bobbin Thread Tension
sion spring, as in-
structed in Fig. 23.
17
TO REGULATE THE LENGTH OF STITCH
BEFORE DEPRESSING PLUNGER (1) MAKE CERTAIN THAT MACHINE
IS NOT RUNNING.
To change the length of stitch, depress plunger and turn machine
pulley, over toward operator, slowly, until plunger drops into notch
in the feed eccentric, as instructed in Fig. 24. Then turn machine pulley,
backward or forward, until numeral representing desired length of
stitch is opposite the mark on the front of the arm.
2. TURN PULLEY
1. DEPRESS TOWARD YOU
Y PLUNGER
“37 UNTIL PLUNGER | |
DROPS INTO NOTCE
|
E4508
4. THEN TURN
PULLEY TO DESIRED
STITCH LENGTH
Di
¡7
Hi
Fig. 24. Regulating Length of Stitch
The numeral “6” on the stitch indicator plate, shown above, indi-
cates the longest possible stitch; the numeral “30” indicates the shortest
stitch.
Release the plunger when the desired setting is obtained.
TO PREVENT OPERATOR FROM CHANGING STITCH LENGTH
The stitch regulator plunger (see Fig. 24) can be removed to
prevent an unauthorized person from changing stitch length.
To remove the plunger, remove the retaining ring near the tip of
the plunger, allowing the plunger to be withdrawn. The hole in the
top cover should then be filled by inserting a plug screw 140607,
which can be obtained at an additional charge.
18
TO REGULATE THE PRESSURE ON THE MATERIAL
The pressure on the material should be as light as possible, while
still sufficient to insure proper feeding.
MORE
PRESSURE ~~
LESS Iv
PRESSURE
Fig. 25. Regulating the Pressure on the Material
Turn the thumb screw, shown in Fig. 25, toward the right to increase
or toward the left to decrease the pressure, as required.
TO SET THE NEEDLE BAR AT THE CORRECT HEIGHT
See that the needle is correctly set in the needle bar, as instructed
on page 8, “TO SET THE NEEDLE.” Then remove the face plate.
The needle bar has two timing marks near its upper end (see Fig. 26).
Rotate the machine pulley over toward the operator until the needle
bar moves down to its lowest position. The upper timing mark on the
needle bar should then be even with the lower end of the needle bar
bushing, as shown in Fig. 26.
To set the needle bar at the correct height, loosen the clamp screw
M, Fig. 26, and raise or lower the needle bar as required. Then se-
curely tighten the screw M.
19
NOTE: If the needle bar bushing N, Fig. 26 has been disturbed, thus
making it impossible to use the timing marks, loosen needle bar bush-
ing set screw P and raise or lower the bushing N as required to bring
the top of bushing flush with top of machine casting, as shown in
Fig. 26. Securely tighten set screw P. The needle bar should then be
set at the correct height as instructed at bottom of page 18.
P— ip!
UPPER
TIMING
MARK
! |
MINE «—M HOOK POINT
MARK AT CENTER
OF NEEDLE
NH 1/64"
NEEDLE BAR | Se
LOWEST POINT N
£74324
Fig. 26. Setting Fig. 27. Needle Bar
Needle Bar Set at Correct Height
Re-time the hook as instructed on page 24. When the hook is
correctly timed and the needle bar is set at the correct height the top
of needle eye will be approximately 1/64 inch below the point of
the hook at the same time that the hook point is at the center of the
needle. See Fig. 27.
When replacing the face plate, make certain that the screw holes
in the face plate gasket are aligned with the respective screw holes
in the face plate, avoiding injury to the gasket and consequent oil
leakage.
20
ADJUSTMENT OF NEEDLE THREAD TAKE-UP SPRING
SETTING THE HEIGHT OF THE SPRING:
Thread the machine. Turn the machine pulley over toward operator
until take-up lever reaches its lowest point and begins to rise.
| - HIGHER Q
a > A > TIGHTEN
EZ LOOSEN
au В ! MORE
5 PRESSURE \
‘ <
LOWER Vi LESS
PRESSURE
Fig. 28. Setting Fig. 29. Adjusting
Height of Spring Tension on Spring
As take-up lever begins to rise, the needle thread is cast off the
hook. The HEIGHT of the thread take-up spring Q should be set so that
at this point (cast-off) the take-up spring will “check” (show a slight dip)
and return to rest.
Later, when take-up lever approaches top of stroke, it begins to set
the stitch, causing the take-up spring to be drawn all the way down.
As take-up lever descends, the take-up spring will return to its
highest point (rest).
To adjust height of take-up spring Q, loosen set screw R and,
by turning stud $, rotate entire take-up assembly over toward right to
raise the spring or over toward the left to lower it. Securely tighten
set screw R.
NOTE: Under certain conditions of tacking, it may be necessary to set
the take-up spring higher than it is otherwise normally set.
ADJUSTING TENSION ON TAKE-UP SPRING:
The tension on the thread take-up spring Q should be sufficient to
ensure its action at high speed. However, it should be light enough to
permit it to be pulled all the way down before any thread is drawn
through the tension discs.
Before adjusting, make certain that set screw Ris securely tightened
so that when stud $ is turned, the remainder of the assembly cannot
turn. Also make certain that the thumb nut is in place on stud $, so that
stud may be turned with screwdriver without breaking.
To adjust tension on take-up spring, turn only the stud S (using
screwdriver with blade large enough to fit snugly into slots in stud)
over toward right to increase tension or over toward left to decrease
tension, as shown in Fig. 29.
NOTE: The tension on the take-up spring may require different settings
depending upon the size of thread used. Heavier thread requires more
tension to ensure correct thread control.
CAUTION: Take-up spring setting must be checked each time a different
foot is applied to machine.
21
TO SET THE PRESSER BAR AT THE CORRECT HEIGHT
When presser bar is fully raised by presser bar lifter and needle
bar is at its lowest position, presser foot should just clear bottom of
needle bar, as shown in Fig. 30.
When presser foot rests squarely on throat plate, with feed dog
below throat plate, there should be a slight amount of play between
guide bracket T, Fig. 30 and lifting bracket U, Fig. 30. This will permit
presser foot to rest firmly upon material.
AT
AT LOWEST
HIGHEST POINT
POINT JUST
CLEAR
Fig. 30. Presser Bar Set at Correct Height
To adjust, loosen clamp screw V, Fig. 30 and raise or lower guide
bracket T, as required.
When presser bar is set at correct height, securely tighten screw V.
CAUTION: Whenever guide bracket has been moved on presser bar,
check take-up spring for correct setting, as instructed on page 20.
22
TO TIME THE SEWING HOOK
The point of the sewing hook should be at the center of the needle,
as shown in Figs. 31 and 32, when lower timing mark on needle bar
reaches the bottom end of needle bar bushing N during the upward
stroke of needle, as shown in Fig. 31.
LOWER
TIMING
MARK
ON
UPWARD
a STROKE
L
Fig. 31. Timing the Sewing Hook
Before checking timing of sewing hook, remove presser foot, feed
dog, slide plate and throat plate.
у Мн —
23
To time the sewing hook turn
machine pulley over toward the
operator until lower timing mark on
needle bar reaches bottom end of
needle bar bushing N, on upward HOOK POINT
stroke of needle. AT CENTER
Then loosen two hub set screws OF NEEDLE
X, Fig. 32, in hub of hook. (The two | |
screws X can be reached from top
of bed with throat plate off.)
While maintaining position of
needle, as described above, turn
hook on its shaft as required to
bring hook point to center of needle,
as shown in Fig. 32. Make certain
that hub of hook is firmly against
hook shaft oil retaining collar K3,
as shown in Fig. 35, then securely
tighten two set screws X. Fig. 32. Sewing Hook Correctly Timed
TO SET THE SEWING HOOK SIDEWISE
IN RELATION TO THE NEEDLE
Sewing hook should never strike needle.
© uE - ‘ > | NOTE- PAPER .
y NON POINT | i
Ш | В | | a Ye AT OF |
Fig. 33. Clearance Between Hook Fig. 34. Checking Clearance Between
Point and Needle Needle and Flat of Hook Point
When point of sewing hook passes needle, clearance between hook
point and needle at D5, Fig. 33 should be approximately equal to
thickness of a piece of note paper (about .005 inch), as shown in Fig. 34.
Not only point of hook but FLAT OF HOOK POINT should clear needle
scarf until heel of flat has passed the needle.
24 25
+
NE
‘+
ъ
Га
ah
AUTOMATIC LUBRICATION SYSTEM OF MACHINES OF CLASS 251-
(Lubrication Shown in Black)
26
HOOK
HUB y
E
Fig. 35. Hub of Hook
Firmly Against Oil
Retaining Collar
Before adjusting the side-
wise position of the sewing
hook, make certain that hook
has been correctly placed on
the hook shaft; the hub of the
hook firmly against the hook
shaft retaining collar K3, as
shown in Fig. 35. See also in-
structions on page 23, under
"TO TIME THE SEWING
HOOK.”
To set the hook sidewise in relation to the needie:
Remove bobbin case, as instructed on page 10.
Loosen hook shaft bushing set screw Z3, Fig. 36.
> у
A In
| REMOVE a
| BOBBIN Не
CASE a 7
:
i
— ——
BUSHING
CS
Fig. 36. Hook Shaft Bushing and Hook Assembly
= =— стен
—
a
HOOK
SHAFT
L2
Fr
, GEARS
IN MESH
Fig. 37. Loosening Hook Shaft Bevel Gear
Loosen the two set screws #1 and #2, on the hook shaft bevel gear
S4, Fig. 37, just enough to loosen the gear on the hook shaft.
CAUTION: MAKE CERTAIN THAT THE TWO BEVEL GEARS L2 AND $4
ARE KEPT IN MESH UNTIL SET SCREWS #1 AND #2 ARE SECURELY
RETIGHTENED.
Using a light mallet and
a 1/4 inch brass drift pin,
as instructed in Figs. 38 to
40, move the hook assem-
bly, toward or away from
the needle, as required.
TAP VERY LIGHTLY on drift
pin to avoid injury to hook
assembly,
DO NOT
HIT BRIDGE
e \
À pures BRASS DRIFT PIN
HERE
Fig. 38. Where to Place
Drift Pin to Move Hook Assembly
Away from Needle
UL ==
28
DO NOT _
HIT BRIDGE >
— — A
=
TAP VERY à =
4” BRASS DRIFT PIN
LIGHTLY 6
Fig. 39. Moving Hook Assembly away from Needle
; DO NOT DAMAGE
— —T
| — BRASS DRIFT PIN TAP
Fig. 40. Moving Hook Assembly toward Needle
When the point of the hook has been correctly set in relation to
the needle, securely tighten the hook shaft bushing set screw Z3,
Fig. 40.
29
Make certain set screw #1, Fig. 37 (the first of two bevel gear set
screws to appear as the machine pulley is turned over toward operator)
seats over flat on hook shaft. Remove all end shake from hook shaft, by
pushing hook firmly against front hook shaft bushing and, at the same
time, pushing gear 54, Fig. 37 toward the hook on the shaft. Securely
tighten first set screw #1, Fig. 37, page 27, then tighten set screw #2.
Time the sewing hook, as instructed on pages 22 and 33.
Replace the bobbin and bobbin case, as instructed on page 13.
FEED ECCENTRIC STOP SCREWS
The machine is prevented from making longer stitches than a pre-
determined maximum by the stop screw W, Fig. 41 in the feed
eccentric.
Feed eccentric stop screw 140256, furnished with Machine 251-1,
permits a maximum length of seven stitches per inch. Stop screw
140258, for 14 stitches per inch or shorter, can also be used. Machines
251-2 and 251-3 are regularly fitted with stop screw 140257 permitting
a maximum length of 5-1/2 stitches per inch, but either 140256
(7 stitches per inch) or 140258 (14 stitches per inch) can be used.
W
Fig. 41. Feed Eccentric Stop Screw
30
TO TIME THE FEED
Before the machine leaves the factory, feed lifting eccentric-and-
bevel-gear and feed eccentric are set for average sewing conditions, by
having timing screw in each eccentric enter groove provided for them
in arm shaft,
As the grooves in the arm shaft are not visible to the adjuster,
machine pulley should be turned over toward operator until feed
lifting eccentric connecting rod A2, Fig. 42 is at its lowest position.
Timing screw Y, Fig. 42 will then be on top of feed lifting eccentric-and-
bevel-gear. Loosen timing screw Y and set screw O and, while main-
taining this position of gear, turn arm shaft until timing screw, as it is
slowly tightened, can be felt to drop into its groove in arm shaft.
Securely tighten timing screw Y and set screw O.
Z
Y
W a O
Fig. 42. Timing the Feed
Feed eccentric timing screw, Z, Fig. 42 appears immediately after
large stop screw W, Fig. 42, when feed eccentric is rotated toward
operator. Feed eccentric should be set for average sewing conditions,
by having this timing screw Z exactly in line with timing screw Y, as
shown in Fig. 42. Thus, as timing screw Z is tightened it will drop into
its groove in arm shaft which is in line with groove provided for feed
lifting eccentric-and-bevel-gear timing screw Y. Securely tighten tim-
ing screw Y and two set screws in feed eccentric.
If, for any reason, it is necessary to alter the timing of either
eccentric, timing screw should be removed and eccentric locked in
desired setting by means of set screws only.
NOTE: Whenever the timing of the feed is changed, sewing hook
should be checked for necessary adjustment also, as instructed on
pages 22 and 23.
31
TO SET THE FEED DOG AT THE CORRECT HEIGHT
FULL DEPTH REAR TEETH
T | 4
T THROAT PLATE
Fig. 43. Showing Feed Dog at Correct Height
When the feed dog is at its
highest position, approximately the >
full depth of the rear teeth of the B?
feed dog should project above the
top surface of the throat plate, as
shown in Fig. 43. A
Before checking the height of C2
the feed dog, set the machine for O ®
the longest stitch, as instructed on X
E;
e 17. O
рез K2
To adjust, loosen the clamping
screw B2, Fig. 44 and raise or lower E?
the feed dog (which is fastened to
the feed bar C2, Fig. 44) as re- (7—0?
quired. Then securely tighten screw Fig. 44. Adiusting
B2. Height of Feed Dog
TO REMOVE THE SEWING HOOK
Remove the needle, slide plate and bobbin case. Remove the screw
D2, Fig. 44 and the bobbin case holder position bracket E2, Fig. 44.
Loosen the two set screws X, Fig. 44 in the hub of the hook and turn
the machine pulley over toward the operator until the feed bar C2
is raised to its highest point.
Turn the sewing hook until the thread guard F2, is at the bottom,
as shown in Figs. 45 and 46, page 32. Turn the bobbin case holder G2,
until the notch J2 is also near the bottom, as shown in Figs. 45 and 46.
The sewing hook can then be removed from the hook shaft.
L2241/2
Fig. 45. Removing and Replacing Bobbin Case Holder
(Correct Position of Bobbin Case Holder in
Relation to the Sewing Hook)
NOTE: While the sewing hook is off the shaft, it is advisable to replace
the oil filter 143350, Fig. 45, in the end of the hook shaft. Unscrew
the filter from the center of the shaft at H2, Fig. 45 and replace with
a complete new filter 143350.
— .
ай
2 вх
7 Xx 12
F?
Fig. 46. Removing Sewing Hook (Correct Position of Thread Guard
and Bobbin Case Holder)
TO REPLACE THE SEWING HOOK
When placing a new sewing hook on the shaft, have the sewing
hook thread guard F2 at the bottom and the bobbin case holder G2
turned to the position shown in Fig. 46, so that the hook will clear
the feed bar C2.
Place the hook in position on the shaft and turn the bobbin case
holder G2 until the notch J2 is at the top. Replace the bobbin case
holder position bracket E2, Fig. 44, making certain that the finger K2,
Fig. 44 enters the notch J2 (which is now at the top of the bobbin case
holder.) Then securely fasten the position finger by means of the screw
D2, Fig. 44.
Replace the needle. Time the sewing hook as instructed on pages
22 and 23. Replace the bobbin case and slide plate.
33
TO REMOVE AND REPLACE THE HOOK SHAFT
Remove and replace the hook shaft in the following manner:—
1. Remove the sewing hook, as instructed on pages 31 and 32.
2. Mark the two lower bevel gears L2 and $4, Fig. 47, with chalk or
crayon, on one tooth of one gear and the corresponding space in
the other gear. This is important, as these gears may become
separated during removal of shaft. These marks will then make it
possible to obtain the original relative position of the gears.
3. While holding the two gears L2 and $4 in mesh, as instructed in
Fig. 47, loosen the two set screws #1 and #2 in the hook shaft bevel
gear, withdraw the old hook shaft and insert the new shaft.
HOLD GEARS IN MESH
Fig. 47. Removing and Replacing Hook Shaft
4. Moke certain that set screw #1 (the first of the two bevel gear set
screws to appear as the machine pulley is turned over toward oper-
ator) seats over flat on the hook shaft. Remove all end shake
from hook shaft, by pushing hook firmly against front hook shaft
bushing and, at the same time, pushing gear $4, Fig. 47 toward
the hook on the shaft. Securely tighten first set screw #1, then
securely tighten the second screw #2.
Replace the sewing hook, as instructed on page 32.
Time the sewing hook, as instructed on pages 22 and 23.
TO REMOVE THE OIL PUMP
Remove the oil pump from the upright arm shaft, in the following
manner: —
1. Loosen the two oil pipe clamping sleeve nuts $2, Fig. 47.
2. Remove the four screws N2, Fig. 47.
3. Remove the screen frame, screen and oil pump cover O2, Fig. 47.
O un
5.
34
Remove the locking screw Q2, Fig. 48 from the center of the up-
right arm shaft, by turning it over toward the left (counterclock-
wise).
Remove the impeller P2, by turning it over toward the RIGHT (clock-
wise) to loosen it, as instructed in Fig. 48.
CAUTION: — The impeller P2 is designed to be screwed to the shaft by
means of a LEFT-HAND THREAD and must be turned over toward the
right to be loosened. Avoid damage to this impeller, as the efficient
automatic lubrication of the machine is dependent upon it.
aS
oe TO LOOSEN
N Q2
д ©
7 Ns
т
Fig. 48. Oil Pump
Remove the three screws T2, Fig. 48.
Carefully pull the old cil pump body off the lower end of the
upright arm shaft.
TO REPLACE THE OIL PUMP
Replace oil pump in the following manner:— |
Place oil pump body on underside of machine bed, so that position
pins V2, slip into proper holes in machine casting as shown in
Fig. 48.
Replace and securely tighten the three screws T2. Make certain
that machine turns freely as screws are tightened.
Carefully replace impeller P2, turning it over toward the LEFT
to SCREW it on arm shaft (see CAUTION above).
Make certain that impeller P2 is not so tight that it will bind
arm shaft and that impeller clears both top and bottom of in-
terior of oil pump body, then lock it in position by means of lock-
ing screw Q2,
Replace pump cover, screen and frame O2 and four screws N2,
Fig. 47. Securely tighten screws N2.
Replace two oil pipes in oil pump body, as shown in Fig. 48, and
securely tighten sleeve nuts 52.
35
TO REMOVE AND REPLACE THE NEEDLE BAR
Remove the needle bar in the follow-
ing manner:—
1. Remove needle and needle set screw r= R2
or needle clamp. и” Y
Remcve face plate. X2°
Loosen clamping screw M, Fig. 49
Loosen screw R2 sufficiently to allow
needle bar to pass, then slip needle
bar up through both needle Баг т | \
bushings and out of machine.
upper needle bar bushing N, Fig. 49, Ох
ко
If it becomes necessary to remove
oil guard W2. Then loosen set screw P pt
and drive bushing N down and out of U
head of machine. Use a 13/32 inch
driving pin.
Before replacing needle bar, replace
upper needle bar bushing N, by driv-
ing it down into hole provided for it in
head of the machine. Make certain top
of bushing N is level with top of arm.
Tighten set screw P.
Replace needle bar in the following
manner: —
1. Slip needle bar down through both
bushings in head of the machine.
Tighten screw M.
2. Replace needle clamp and needle. See page 8.
3. Set needle bar at correct height and replace face plate, as
structed in last paragraph on page 19.
4. Replace oil guard W2 and fasten it securely to bushing with
screw R2,
TO REMOVE AND REPLACE THE PRESSER BAR
To remove the presser bar:—
Remove presser foot and face plate.
——
first remove screw R2 and take-up lever cu Va _
Fig. 49. Removing and Replacing
Needle Bar and Presser Bar
—
-
In-
set
2. Remove presser bar regulating thumb screw, X2, Fig. 49 with upper
section of presser bar from the head of the machine.
3. Loosen clamping screw V and screw A5 and slip guide bracket T up
off presser bar and out of machine.
4. Slide presser bar up through bushing and out of machine.
To replace the presser bar:—
1. Slip presser bar down through lower presser bar bushing.
2. Replace guide bracket T as shown in Fig. 49.
3. Replace presser foot.
4. Replace presser bar regulating thumb screw X2 with upper section
of presser bar.
5. Set the presser bar at the correct height, as instructed on page 21.
Tighten screw V.
6. Tighten screw A5 making sure that slack thread regulator B5 just
clears the casting. Replace face plate, as instructed on page 19.
36
TO REMOVE NEEDLE BAR LINK AND THREAD TAKE-UP
Remove needle bar link and thread take-up in the following
manner:—
1.
DO NOT
DISTURB ~+F3 £2 у?
Remove face plate and arm
hole plug A3, Fig. 50 from ma-
chine.
Remove needle bar, upper
needle bar bushing, presser
bar and guide bracket T, Fig. 51 a
as instructed on page 35. #10
Loosen set screw Y2, Fig. 50 in
needle bar crank, reaching
with a screwdriver through the po NOT
hole in the arm, opened by re- pISTURB U?
moval of plug A3, and turning
machine pulley as required. Fig. 50. Needle Bar Crank
Using wrench 146057 (through same hole) and turning machine
pulley as required, loosen the large hexagon head clamping screw
Z2, Fig. 50, on the needle bar crank.
CAUTION: DO NOT DISTURB the smaller hexagon head position screw
U2, Fig. 50, which holds the needle bar crank at its correct position on
the horizontal arm shaft.
5. loosen small set screw B3, Fig.
51 in the rear of the arm of the
machine.
6. Insert a face plate screw E3,
Fig. 51 in the tapped hole in
center of stud C3, Fig. 51 and,
while holding back the needle
bar link inside the head at G3,
Fig. 51, pull upon the screw E3
until the stud C3 is removed.
Remove face plate screw from
stud.
7. Back the end of the take-up
H3, Fig. 51 toward the inside
of the machine turning the ma-
chine pulley, as required until
Fig. 51. Needle Bar Link the take-up is free of the slot
and Thread Take-up provided for it.
The needle bar link G3 and take-up H3 can now be pulled free of
the needle bar crank WITHOUT DISTURBING THE NEEDLE BEAR-
INGS F3, Fig. 50.
37
NOTE: If the needle bearings F3, Fig. 50, are accidentally disturbed,
they must be re-assembled so that there are exactly 18 bearings in
each of the two assemblies.
TO REPLACE THE NEEDLE BAR LINK AND THREAD TAKE-UP
Replace the needle bar link and thread take-up in the following
manner: -—
1. Make sure that the wearing plate J3 is in place on the face of the
needle bar crank, as shown in Fig. 51. Place the needle bar link
G3 and take-up H3 in the head of the machine so that the stud in
the center of the linkage slips into the hole provided for it in the
needle bar crank, as shown in Figs. 50 and 51.
2. Slip the upper end of the take-up H3 through the slot provided
for it in the head of the machine.
3. Insert stud C3 through needle bar link G3 and into its hole in the
machine casting so that the flat on the stud faces the rear of the
machine. The mark D3 on the stud indicates the position of this
flat. Fig. 51 shows the stud with the mark D3 in the correct
position.
4. When the stud C3 is fully and correctly inserted, turn the set screw
B3 inward lightly against the flat on the stud C3.
5. Insert a screwdriver through the hole in the front of the head of
the machine and turn machine pulley as required to reach set
screw Y2 in needle bar crank. While tightening screw Y2, turn
stud W4 by hand to find its flat, then slightly tighten set screw Y2
in needle bar crank. Make certain that assembly F3 is firmly
against wearing plate J3. Produce a very slight side play by
pushing take-up lever H3 gently right and left; then securely
tighten screw B3.
6. Using wrench 146057 through same hole and turning machine
pulley as required, tighten hexagon head screw Z2.
7. Securely tighten set screw Y2.
Replace guide bracket T in head of machine, as shown in Fig. 51.
9. Replace and adjust presser bar, upper needle bar bushing and
needle bar with their accessories, as instructed on pages 19 and
35.
10. Replace and securely tighten arm hole plug A3.
11. Replace the face plate (see instructions at bottom of page 19).
38
TO REMOVE AND REPLACE THE UPRIGHT ARM SHAFT
If it is found necessary to remove the upright arm shaft K3, Fig. 52
r
it should be removed in the following manner:—
1.
10.
11.
12.
13.
Remove oil pump, as in-
structed on pages 33 and 34.
Remove sewing hook shaft, as
instructed on page 33, except
that instead of immediately
replacing hook shaft merely
remove hook shaft bevel gear.
Remove arm top cover.
Remove screw L3 and oil lead
M3, Fig. 52.
Remove four cap screws N3,
Fig. 52.
Remove oil flow window cap
O3, window P3, oil flow body
R3 with two gaskets Q3, Fig.
52.
Mark the two bevel gears $3,
Fig. 52, with chalk or crayon,
on one tooth of one gear and
the corresponding space be-
tween the teeth of the other
gear so that these gears may
be re-assembled, if necessary,
in their original relative posi-
tions without difficulty.
Fig. 52. Removing Upright Arm Shaft
Loosen set screws T3, Fig. 52 in bevel gear at upper end of up-
right arm shaft.
Make certain bevel gear at lower end of upright arm shaft is
fastened securely. Then while holding upper bevel gears $3 in
mesh, draw upright arm shaft down and out of machine and
insert new upright arm shaft up through bevel gear, as shown
in Fig. 52.
Turn shaft so that one of the two set screws T3 will bear upon the
upper gear flat on the shaft and tighten the set screws T3.
Replace hook shaft with hook shaft bevel gear as instructed on
page 33.
Replace oil pump, as instructed on page 34.
Replace oil flow window assembly, oil lead and arm top cover
as shown in Fig. 52.
39
TO REMOVE AND REPLACE ARM SIDE SHIELD WICK, NEEDLE BAR WICK
AND NEEDLE BAR CONNECTING STUD WICK
Arm side shield wick may be removed, after removing face plate
and two screws U3, Fig. 53. Lift arm side shield V3, Fig. 53 up and out
of machine.
When replacing arm side shield
wick, make sure that lower end of
wick drops into oil pool beneath
needle bar crank and that the two
upper wick loops come as close as
possible to the needle bearings F3, MR?
Fig. 54 without touching them. Then «-H3
replace and securely tighten screws W2
Us. Ш
To remove needle bar wick and
connecting stud wick, move take-up SHIELD NEEDLE
ever H3, so that it does not inter- wick” | —— BAR
ere with removal of oil guard W2. o WICK
Then remove face plate and screw o ‘В.
R2, Fig. 53; lift take-up oil guard Y Wy
W2, Fig. 53, with the two wicks,
up and out of machine.
When replacing needle bar
wick and connecting stud wick Fig. 53. Arm Side Shield Wick, Needle Bar
make sure that lower end of wick Wick and Connecting Stud Wick
drops into oil pool behind lower needle bar bushing and that upper
wick loop is behind the needle bar, as shown in Fig. 53.
TO REMOVE OIL WICK HOLDER
Oil wick holder includes two oil wick leaders, see Fig. 55, and one
oil wick for the needle bar link and for the two sets of needle bearings
in the thread take-up as shown in Fig. 54. It is removed in the follow-
ing manner:—
1. Remove face plate, needle bar
and upper needle bar bushing
from the machine, as instructed
on page 35.
2. Remove upper section of presser
bar, as instructed on page 35.
3. Remove stud C3, Fig. 46, as in-
structed in steps 6 and 7 on
page 36.
4. Remove holder screw WS3,
Fig. 54.
5. Pulling gently, draw entire oil
Fig. 54. Wick Loops for Needle wick holder assembly out of the
Bar Link and Thread Take-up head of the machine.
TO INSTALL OIL WICK HOLDER
1. Remove parts mentioned in Steps 1 to 3, above, under removal
of oil wick holder.
40
2. Remove top arm plug Y3,
Figs. 54 and 55. Use a sharp-
bladed screwdriver or a small
chisel to pry plug Y3 from arm
casting.
Insert two oil wick leaders into
arm casting, as shown in Fig.
55, so that wick is slack over
edge of casting at point A4,
Fig. 55. This will insure free
passage of oil. Use tweezers
through the plug hole at Y3
to loop the wick and bring it
into positive contact with the
arm shaft at point B4, as
W3
4
Ta
HOLDER LEADERS
A 3
A
{7
ou”
£ 25154
Fig. 55. Replacing Oil Wick Holder
shown in Fig. 55.
NOTE: DO NOT FORCE the wick leaders down too tightly against
the edge A4 of the casting, as shown in Fig. 56, as this will de-
WICK
PINCHED
us |
Fig. 56. Incorrect installation
crease the flow of oil from the arm
shaft to the needie bar link and
take-up bearings.
CAUTION: If the bottom of either
oil wick leader is caught on the
ledge as shown at C4, Fig. 57, no
oil can be taken up by the wick
to be carried to the needle bar link
and thread take-up bearing, where
it is needed. Make sure that the oil
wick leaders are pushed all the
way down into the smaller hole,
without jamming, until they touch
the arm shaft, as shown in Fig. 55.
When oil wick leaders are correctly installed, replace holder
screw W3, Fig. 54.
Replace stud C3, as instructed
in Steps 3 and 4, under re- ;
placement of needle bar link ‘
and thread take-up, on
page 36.
Adjust the three oil wick loops
in holder, see Figs. 54 and
55, so that two of the loops
come as close as possible to,
without touching, the two sets
of needle bearings F3 while
the third wick loop makes posi-
tive contact with the wick in-
side the stud C3, in the needle
bar link, as shown in Fig. 54.
WICK
NOT REACHING
OIL
E25156
Fig. 57. Incorrect Installation
41
7. Securely tighten holder screw W3.
8. Replace arm top plug Y3.
9. Replace upper section of presser bar, upper needle bar bushing
and needle bar, as instructed on page 35.
10. Replace face plate, as instructed in last paragraph on page 19.
OIL-REMOVING WICK ASSEMBLY (HEAD END) COMPLETE 147056
The function of the oil-removing wick assembly, Complete 147056,
furnished with the machine, is to remove excess oil from the head of
the machine arm.
This assembly is shown in Fig. 60. Additional sets of the oil-remov-
ing wick, wick holder body and spring, Complete 147108, shown in
Fig. 60, will be furnished on order.
CAUTION: If inferior oil is used, absorption of the excess oil by this
wick may be reduced considerably. The consequent leakage of ac-
cumulated oil will then cause serious damage to materials being sewn.
When filling the machine reservoir use “TYPE A" or “TYPE C” OIL,
sold by Singer Sewing Machine Company. For further instructions on
oiling, see inside front cover of this book and pages 5, 6, 39 and 40.
CAUTION: Before inserting a new oil removing wick, it must be satu-
rated with oil.
TO REMOVE OIL-REMOVING WICK ASSEMBLY
Oil-removing wick assembly 147056 should be removed in the
following manner:— |
| X2
2. loosen presser foot lifting lever |
hinge screw E4, Fig. 58. |
3. loosen presser foot lifting lever
link stud screw F4, Fig. 58.
4. Remove head end of presser
foot lifting lever G4 with
spring H4, Fig. 58 from the
machine arm.
1. Remove face plate.
5. Remove presser foot screw and
presser foot.
6. Remove presser bar thumb
screw X2, Fig. 58 with upper
section of presser bar.
7. Remove arm side shield with
wick, as instructed on page 39.
8. Loosen screw V and remove
guide bracket T, Fig. 58, as in-
structed on page 35.
9. Remove presser bar lifting link
J4, Fig. 58 with stud.
10. Loosen four screws K4, Fig. 58
in the oil removing hinge plate
and cover L4, Fig. 58.
Fig. 58. Preparing to
Remove Oil-Removing Wick
43
TO REPLACE OIL-REMOVING WICK ASSEMBLY
42
11. Turn machine pulley over
| | o > | Ой-гетоу!па wick assembly
| Е | toward the operator, until the P4 SLIP CATCH should be replaced in the following
needle bar crank is in the posi- - TN \ manner: —
tion shown at M4, Fig. 59. a Ty 9 1. Insert open end of holder body
| ) = > O4, Fig. 61 into hinge plate
12. Lift wick LOOP up and off - Ku > (DE = and cover L4.
lower presser bar bushing and La 2, Replace and securely tighten
lift wick END out of oil pool В hinge screw as instructed in
behind needle bar bushing, REPLACE | Fig. 61.
as shown in Fig. 59. HINGE В 3. Slip end of spring into catch
SCREW on holder body O4, as in-
| structed in Fig. 61.
13. Simultaneously push upward
against wick and wick holder | 4. Place gasket P4, Fig. 61 on
at N4, while pulling outward hinge plate and cover L4.
5. Align the screw holes in the
entl hi lat d
gently on hinge plate an gasket P4 with the screw holes
po o — cover L4, as shown in Fig. 59, a in the cover L4 and insert the
4, ETE | removing hinge plate and Fig. 61. Replacing four screws K4, Fig. 62 through
SS a 4h oil ik Oil-Removing Wick cover and gasket to hold the
cover with oil-removing wic in Assembly 147056 gasket in place.
Fig. 59. Removing and holder body from the ma-
Oil-Removing Wick CAUTION: Before inserting a new oil removing wick, it must be saturated
Assembly 147056 chine. with oil
14. RELEASE SPRING
~~ FROM CATCH
14. Release end of spring from ВЕ я Y os
catch on the holder body O4, AN S | *
as instructed in Fig. 60. В , | KA pa
т
li ( co + e BC
15. Remove hinge screw, as in- } 7 Na \
structed in Fig. 60. 15. REMOVE НЙ J
HINGE | 24
16. Oil-removing wick and holder SCREW В E La
N4 may then be removed from ) - | a ,
h'nge plate and cover L4, as |
shown in Fig. 60.
Fig. 62. Replacing Oil-Removing Wick and Holder
in Head of Machine
6. Turn machine pulley over toward operator until needle bar crank
oilnl 80 Removing is in the position shown at M4, Fig. 62.
Assembly 147056 7. Fold oil-removing wick along the side of the holder body, as
(Showing Oil-Removing Wick, shown in Fig. 62 and insert oil-removing wick, holder and hinge
Wick Holder Body and Spring 147108) plate into head of machine.
10.
44
Place index finger under wick
and holder body and simultane-
ously pull the oil-removing
wick, as required, sliding the
hinge plate and cover L4 fully
into its recess in the head of the
machine, as shown in Fig. 63.
Securely tighten the four screws
K4, Fig. 62.
Check the entire assembly to
make certain that the holder
body O4, Fig. 61 hinges freely
under the needle bar crank.
11.
Fig. 64. Locotion 14
of Loop and End of
Wick in Head of Machine
13.
SLIDE
INTO
RECESS
Fig. 63. Adjusting
Wick in Machine
Replace END of wick behind
tension releasing lever Q4 and
into oil pool behind lower
needle bar bushing, as shown
in Fig. 64.
Replace LOOP behind and un-
der tension releasing lever Q4
and then out over lower
presrrr bar bushing, as shown
in Fig. 64.
Replace presser bar and lifter
assembly, part for part, in the
reverse order of their removal
as instructed in Steps 2 to 9
on page 41.
Replace face plate, as in-
structed on page 19.
45
TO REMOVE THE ARM SHAFT
The horizontal arm shaft should be removed from the arm of the
machine in the following manner:—
1.
2,
3
4.
10.
TT.
13.
Remove the arm side shield and wick, as instructed on page 39.
Remove the thread take-up oil guard, as instructed on page 39.
Remove the needle bar, upper needle bar bushing, presser foot
and presser bar, as instructed on page 35.
Remove entire thread take-up lever assembly, as instructed on
page 36.
Remove the oil-removing wick, as instructed on pages 41 and 42.
Set the machine at any stitch length except the longest or the
shortest (see instructions on page 17) to prevent binding of the
arm shaft during removal and replacement.
Loosen the four screws in the arm top cover and remove the arm
top cover.
Remove the oil lead that is fastened to the casting just beneath
the arm top cover.
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14
Fig. 65. Loosening the Feed Eccentric
Remove the feed timing screw Y, Fig. 65 and loosen the set screw
O, Fig. 65, in the feed-lifting-eccentric-and-bevel-gear, X3, Fig. 65.
Remove the timing screw Z and loosen set screws in the feed
eccentric U4, Fig. 65.
Remove arm shaft screw R4, Fig. 65 from machine pulley end of
arm shaft.
Loosen the two set screws T4, Fig. 65 and remove the machine
pulley.
Turn the needle bar crank until it is in the position shown at M4,
Fig. 66, to prevent crank from disturbing the three wick loops in
holder W4, Fig. 66, during removal of arm shaft.
46
CAUTION: The feed timing bevel
gears at $3 have been lapped to-
gether at the factory and should
be kept in mesh, as instructed in
Fig. 67, throughout the removal and
replacement of the arm shaft.
14. While maintaining position of
16.
needle bar crank, as described
in Step 13 on page 45, hold
the blade of a large screw-
driver between the arm cast-
ing and the feed eccentric U4, M4
as shown in Fig. 67, to keep
the bevel gears in mesh and
push the end of the arm shaft
X4, Fig. 67 into the bushing
ZA, Fig. 67.
Fig. 66. Position of
Needle Bar Crank, During
Removal of Shaft
y
a A XA
> $3
HOLD THESE GEARS IN MESH
Fig. 67. Removing the Arm Shaft
Using another shaft, of the same diameter as the arm shaft on
these machines, push the arm shaft X4 further through the ma-
chine (still keeping the gears at 53 in mesh). This temporary shaft
must be pushed sufficiently far into the machine to hold the entire
gear and feed eccentric mechanism in position upon it until the
arm shaft is replaced.
Finally grasp the needle-bar-crank-end of the arm shaft firmly
and pull the arm shaft straight out of the machine.
47
TO REPLACE THE ARM SHAFT
CAUTION: — Make certain that the OIL-REMOVING WICK ASSEMBLY
is out of the machine.
1.
2.
Insert the machine-pulley-end of the arm shaft into the arm shaft
bushing at the head of the machine arm.
Make certain that the needle bar crank is turned to the relative
position shown in Fig. 66 to clear the three wick loops in holder
Wa.
While still holding the bevel gears at $3 in mesh, with a screw-
driver, as shown in Fig. 68, push the arm shaft X4 straight through
the machine arm, the feed eccentric U4 and the feed-eccentric-
and-bevel-gear, X3, Fig. 68. (A light tapping with the palm of the
hand, against the needle bar crank end, may be required.)
V V4
HOLD THESE GEARS IN MESH T4
Fig. 68. Replacing the Arm Shott
Replace machine pulley so that the two set screws T4 will locate
over the two grooves V4, Fig. 68 on the shaft and securely tighten
set screw T4,
Replace and tighten the arm shaft screw R4 sufficiently to remove
all end play of the shaft without binding. Test the arm shaft for
freedom in rotation.
Move bevel gear X3 toward machine pulley and securely tighten
feed timing screw Y.
Place the first finger of one hand on one side of the arm shaft and
the first finger of the other hand on the other side of the arm shaft
so that both fingers contact the bevel gear (on vertical shaft) that
mates with the gear X3. Feel for slight backlash. If there is no
backlash, loosen timing screw Y and set screw O. Lightly tap gear
X3 away from mating gear until there is just a slight amount of
backlash. Then securely tighten timing screw Y and the set screws
in gear X3. Recheck the backlash.
Using a screwdriver, as shown in Fig. 68, move feed eccentric U4
as close as possible to the connecting rod A2, Fig. 68 and tighten
the timing screw and two set screws in eccentric U4,
10.
11.
12.
13.
14.
15.
16.
17.
18.
48
Check the adjustment and timing of parts disturbed and correct
where necessary, according to the instructions on pages 18
through 30.
Replace the oil-removing wick assembly, as instructed on pages
43 and 44.
Replace thread take-up, as instructed on page 35.
Replace presser bar and presser foot, as instructed on page 35.
Replace the upper needle bar bushing and the needle bar, as
instructed on page 35.
Replace thread take-up oil guard, as instructed on page 39.
Replace the arms side shield and wick, as instructed on page 39.
Replace the oil lead beneath the arm top cover.
Replace the arm top cover and tighten its four screws.
Replace the face plate and tighten its four screws.
CAUTION TO MECHANICS
Machines of Class 251- are made with extreme precision in ma-
chining and assembly, and the “Superfinish” process provides mi-
croscopically smooth bearing surfaces. Therefore, special care should
be taken not to permit any misalignment or cause any scratches or
nicks on the bearing surfaces by careless assembly or handling of
parts. Any such damage might render the machine incapable of the
long trouble-free service for which it is designed.
TO ALL WHOM IT MAY CONCERN:
The improper placing or renewal of the Trade Mark “SINGER” or
any other of the Trade Marks of The Singer Manufacturing Company
(all of which are duly Registered Trade Marks) on any machine that has
been repaired, rebuilt, reconditioned, or altered in any way whatsoever
outside a SINGER factory or an authorized SINGER agency is forbidden.
THE IMPORTANCE OF USING
SINCER" PARTS AND NEEDLES
IN SINGER MACHINES
The successful operation of SINGER machines can only be assured
if SINGER parts and needles are used. Supplies are available at all
SINGER Shops for the Manufacturing Trade, and mail orders will
receive prompt attention.
SINGER Needles should be used
in SINGER Machines
These Needles and their Containers
are marked with the
Company's Trade Mark "SIMANCO.*" 1
Needles in Containers marked
"FOR SINGER MACHINES”
are NOT SINGER made needles. >
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