Singer Class 457 G 1 User manual

Form 30252 G
(1062)
SERVICE MANUAL
for
SINGER
MACHINE
Class 457G1
Machine Class 457G1
•.,u-r,^.V;t i-.-s
SINGER NAHMASCHINENFABRIK KARLSRUHE AKTIENGESELLSCHAFT
KARLSRUHE/BADEN (GERMANY)
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CONTENTS
Page
Description 3
Speed 3
Setting Up 3
Lubrication 4
Adjustment of the Oil Flow for the Hook Lubrication . . . 4
Needles 5
Thread 5
To remove the Bobbin Case Cap 6
To wind the Bobbin 6
To thread the Bobbin Cose 7
Toreplace the Bobbin Case 7
To set the Needle 7
Upper Threading 8
Toprepare for Sewing 8
Toregulate the Tensions 8
Toregulate the
Length of the Stitch 9
Toset the Width of the Zig-Zog Stitch 9
To clean the Hook and the Thread Ways 9
Timing and other Adjustments 10
Toset the Thread Take-up Spring 10
To set the Presser Bar 10
Toregulate the Pressureof the Presser Baron the Material 11
To set the Tension Reieaser 11
To set the Needle Bar at the correct Height . . . . .12
To time the Hook 13
To time the Feed Driving Eccentric 14
To set the Feed Dog 15
To set the Needle Vibrating Mechanism 15
To set the Needle Bar Yoke 16
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DESCRIPTION
The 457 G 1 machine is a high speed, single needle,
lock stitch, zig-zag sewing machine for stitching light
and medium weignt fabrics.
^ The machine specifications are as follows: -
1. Needle Bar Stroke 1-5/16 inch = 33.40 mm
Presser Bar Lift 9/32 inch = 7.15 mm
Maximum Width of
Zig-Zag Stitch 5/32 inch = 4.00 mm
Space at right of Needle 8-3/16 inch = 208.00 mm
Maximum Length of Stitch 6 stitches per inch
= 4.20 mm per stitch
Bed 15-11/16 inches long, 7 inches wide
= 398.50 mm long, 177.80 mm wide
MachinePulley(SafetyType) for
3/8 inch= 9.50 mm
V-Belt. Outside diameter of belt groove 2.9 inches
= 73.65 mm. Effective diameter for 5/16 inch =
7.93 mm round leather belt 2-3/8 inches = 60.30 mm.
2. Automatic lubricating system for supplying oil to
all moving parts which can be observed through an
oil flow window at the front of the machine arm.
3. Transverse, two toone, horizontal axis rotary hook,
automatically pressure lubricated and with fine ad
justment for the oil flow.
4. Single rotary take-up which controls thread at all
times to meet the requirements of the hook.
5. Thread pretension and rotary thread tension for
proper regulation of the stitch formation.
6. Thewidth of the zig-zag stitch isset by turning the
bight control knob and the corresponding setting
is indicated at the front of the machine.
7. The length of the stitch is adjusted by changing the
feed driving eccentric on the bed shaft and the set
ting is indicated on the machine pulley.
8. Pendant link mechanism with eccentricfor adjusting
the feed dog to height and parallelism.
9. Low inertia presser bar mechanism.
10. The arm shaft, the needle vibrating shaft and the
belt end of the bed shaft are mounted in double-
shielded ball bearings.
Needle bearings for the needle bar yoke connec
ting link and the feed driving eccentric connection;
super-oilite bushings for the feed driving eccentric
rockshaft, the needle bar yoke shaft and the needle
vibrating eccentric connection link.
11. The removable arm cover permits accessibility to
all parts in the arm.
12. Vibration absorbing location of the machine in the
machine base whioi is firmly mounted as oil pan
and oil reservoir in the table.
SPEED
The maximum speed recommended for this machine
^ 5000 R.P.M. depending on materials used and opera-
ons performed. It is advisable to run a new machine
-or a more moderate speed until an oil flow is visible in
the oil flow window and this speed should be maintain
ed for several minutes. When the machine is In operat
ion, the machine pulley must always turn over toward
the operator.
SETTING UP
The machine rests on a cork gasket in the machine
base. The machine base also serves as drip pan, oil re
servoir and as housing for the knee lifter.
When using the SINGER-table the machine base rests
on its four cornersand is fastened by meansof rest pins
(wooden) furnished with the machine. Any table-cut-out
into
which the machine base cannot be inserted pro
perly must be reworked or adjusted by
shims so that
the machine base
1. does not rock,
2. is level in both directions,
3. prevents the inserted machine from touching
the table,
4. raises the inserted machine above the table,
enough to open the bed slide and that the
bed hinge connections support the machine
only when it is tilted back.
When assembling the knee lifter make certain that
the knee lifter pin is properly inserted to connect the
knee lifter mechanism of the machine with that of the
machine base. The lifting range of the knee lifting lever
sfc^n be adjusted by the screw"A", Fig. 1 (no lifting) and
^ the screw "B", Fig. 1 (full lifting). When using the
~-itill lifting range, the lifted presser bar lifter must disen
gage.
itufr'"-'
Figure 1
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The static grounding contact "C", Fig. 2 with ground
ing contact wire, furnished with the machine, provides
for the static grounding of the machine
and will be fas
tened at the rear side of the machine base in such a
manner that a contact with the machinebed is obtained.
The paint should be removed from the contacting area
of the machine bed and the grounding contact be fas
tened at the rest plate of the motor.
Caution: Make certain that all instructions for the
lubrication of the machine are complied with before
starting the machine. This also refers to checking the
speed.
0
Figure 2
LUBRICATION
Use only "Type C" oil, sold by the Singer Sewing Ma
chine Company, for the automatic lubrication of the
machine. Tnis type of oil assures atroublefree lubrica
tion and increases the life of the machine.
Before starting the machine fill the oil reservoir in the
machine base up to the "HIGH" mark. The screw-type-
pump, mounted in the machine bed, supplies oil to the
hook and to the machine parts and the oil supplied is
protected by a screen against dirt.
The level of the oil should be checked daily
and refill
ed when necessary. Never allow the oil level to drop
below the "ADD OIL" mark.
The oil screen should be cleaned as often as required
depending upon the operations performed.
ADJUSTMENT OF THE OIL FLOW FOR THE
HOOK LUBRICATION
The regulating screw "D", Fig. 3 locked in place by
a lock nut and located at the head side of the hook
shaft gear box, regulates the oil flow for the lubrication
of the hook. The oil flow is set at the factory for auto
matic lubrication of the hook under normal sewing con
ditions. In general, the normal adjustment can be made
as follows: Turn the regulating screw in to its closed
position
and then loosen by approx. 2-^^^ turns. Turn the
regulating screw (to the right) to increase the flow •*"
oil to the hook and turn the regulating screw out (to tl.^
left) to decrease the flowof oil to the hook.
The oil wick "E", Fig. 4 in the oil filter screw at the
front end of the hook shaft must be replaced occasio
nally as it may have collected lint or other foreign mat
ter causing an insufficient supply of oil to the hook.
Figures 3 and 4
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If the hook receives on excessive amount of oil which
cannot be reduced by the regulating screw, check to be
sure that
1. the oil wick has not become detached from
the filter screw,
2. the filter screw is securely tightened,
3. the oil return passages
In the hook shaft, the
bushing or inthe hook bushing housing hove
not become clogged with lint or other fo
reign matter.
Todetermine the proper flow of oil to the hook clean
the hookand, with the machine running at normal ope
rating speed, hold a small piece of white paper under
the hook for approx. 15 seconds without moving the
paper or changing the speed. If the paper shows an oil
streak of approx. 1/32 inch = 0.8 mm width the hook
receives sufficient oil.
NEEDLES
The needles recommended for this machine are Ori
ginal SINGER-Needles Cat. No. 1905 (Syst. 265} chro
mium finish, available in the sizes 7-25.
The size of the needle to be used should be determin
ed 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
ofthe needle will interfere with the successful operation
y the machine.
Orders for needles mustspecifythe quantity required,
the catalogue number, the size number and the
finish.
Example: 100 - 1905 - 14 - 1
100 (Needles) 1905 (Cat. No.) 14 (Size)
1 (Chromium Finish)
SINGER-Needles and packets are stamped with the
trademark "SINGER".
THREAD
Only left twist thread should be used in the needle
(upper thread).
Either left or right twist thread can be used in the
bobbin (bobbin thread).
Figure 5
To determine the thread twist hold the thread as
shown in Fig. 5. Turn the thread toward the operator
between the thumb and forefinger of the right hand; if
left twist, the strands will wind together; if right twist,
the strands will unwind.
Based on past experience the sizes of the needles and
threads recommended for this machine are as follows:
Thread 60/3 70/3 80/3 - Needle Size No. 14
40/3 50/3 60/3 - Needle Size No. 16
30/3 40/3 - Needle Size No. 18
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TO REMOVE THE BOBBIN CASE CAP
First, turn the machine pulley toward the operator
until the needle is at its highest point. After the bed
slide has been opened reach under the table, open the
bobbin case latch Fig. 6 and remove the bobbin
case cap from the hook by means of this latch. While
the latch remains open, the bobbin will be retained in
the bobbin case cap.
TO WIND THE BOBBIN
Fasten the bobbin winder to the table with its driving
pulley in front of the machine belt so
that the pulley
will be released when sufficient thread has been wound
upon the bobbin.
Place the bobbin on the bobbin winder spindle and
push it on as far as it will go.
Next pass the thread through the thread guide in the
tension bracket "G", Fig.7 and around the tension discs
to the bobbin. Then wind the end of the thread around
the bobbin a few times and push the bobbin winder
pulley against the machine belt and start the machine.
When sufficient thread has been wound upon the bob
bin, the bobbin winder will stop automatically. If the
thread does not wind evenly on the bobbin, loosen the
screw "H", Fig. 7 at the tension bracket and move same
to the right or left as required. Then retighten the screw
"H", Fig. 7.
The amount of thread wound on the bobbin is regu
lated by the screw
"J", Fig. 7. To wind more thread on
the bobbin, turn the screw to the right; for less thread
turn the screw to the left.
Bobbins can be wound whilethe machineisstitching.
0
Figure 6
Figure 7
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03
Figure 8
L M N 0
mz
Figure 9
TO THREAD THE BOBBIN CASE
(
\
Hold the bobbin between thumb and forefinger of
the right hand as shown in Figure 8 so that the thread
will unwind to the left.
Hold the bobbin case with the left hand as shown in
Figure 8, with the spring upward and place the bobbin
into the bobbin case.
Pull the thread into the slot "L", Fig. 9 under the
spring Fig.9, through the next slot
"N", Fig.9 into
the bobbin case and lead the thread out through the
third slot "O", Fig. 9.
TO REPLACE THE BOBBIN CASE
After threading take the bobbin case by the latch and
place it on the center stud of the bobbin case base hol
der. Release the latch, press the bobbin case until the
latch catches the groove near the end of the stud. Allow
about 2 inch. = 50,8 mm of thread to hang free and
close the bed slide.
TO SET THE NEEDLE
Turn the machine pulley toward you until the needle
bar reaches its highest point. Loosen the needle set
screw at the lower end of the needle bar and push the
needle into the bar to the needle stop with the long
groove and the eye facing the operator. Then securely
tighten the needle set screw.
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UPPER THREADING
As soon OS the operator has become accustomed to
threading the machine, the thread can be passed with
a single continuous motion from the thread guide to the
needle eye.
First, turn the machine pulley toward the operator
until the needle Isat its hignest position. From the spool
holder pass the needle thread from right to left through
the rear hole of the thread guide "P", Fig.10 on the arm
cover
and then from left to right through the front hole.
Now draw the thread from right to left through the up
per hole of the thread guide "R", Fig. 10 on the pre
tension
and from left to right through the lower hole.
Insert the thread from right into the pretension "S",
Fig. 10, lead 1-1/2 times clockwise around the tension
wheel "T", Fig. 10, over the
thread take-up spring "U",
Fig. 10,
under the thread pull-off "V", Fig. 10 and to the
thread guide hole of the long thread guide "W", Fig. 10.
Then pass the thread through the opening in front of
the face plate "X", Fig. 10, over the thread take-up
lever "Y", Fig. 10, down through the thread guide eye
"Z", Fig. 10, through the needle
bar thread guide "AA",
Fig. 10
and from front to rear through the eye of the
needle.
Figure 10
TO PREPARE FOR SEWING
With the left hand hold the slock end of needle thread
loosely and turn the machine pulley toward you until
the needle moves down and up again to its highest
point thus catching the bobbin thread. Then draw up
the needle thread and the bobbin thread will come with
it. Lay both threads back under the presser foot.
TO REGULATE THE TENSIONS
The upper and bobbin threads should be locked in
the center of the thickness of the material. Fig. 11.
Ifthe 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, Fig. 12.
Ifthe 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 underside of the ma
terial, Fig. 13.
Thetension on the needle thread should be regulated
only when the presser foot is down and the thread ten
sion not released. The tension is regulated by means
of the tension thumb nut "AB", Fig.10.
The tension on the bobbin thread is regulated by
means of the small regulating screw "K", Fig. 8, in the
bobbin case cap tension spring. To increase the tension,
turn the screw to the right. To decrease the tension, turn
the screw to the left. At the standard setting
(= for nor
mal sewing) the bobbin thread should just carry the
weight of the bobbin case cap with the inserted bobbin.
Figure 11
Figure 12
Figure 13
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TO REGULATE THE LENGTH OF THE STITCH
To change the length of the stitch stop the machine,
then press down the stitch regulator plunger "AC",
g. 14 in the bed and at the same time turn the machine
•pulley toward the operator until the plunger enters a
notch in the teed driving eccentric. Turn the machine
pulley until the desired number of stitches per inch on
the machine pulley is opposite the reference mark on
the front of the arm.
Number 6 on the scale will indicate the longest stitch
and number 30 the shortest one which can be obtained
with this machine.
Caution: Never depress the stitch regulator plunger
while the machine is in operation.
-rf ,10
AE AD
Figure 14
TO SET THE WIDTH OF
THE ZIG-ZAG STITCH
By turning the needle vibrator adjusting knob "AE",
Fig. 14 on the front side of the arm, the desired bight
can be set and the same checked on the dial "AD",
Fig. 14 in five successive steps of
1/32 inch = 0.8 mm
each.
The setting is to be done when the machine is out of
•^^eration. The dial reading "O" shows the straight
•ft^-hch and the dial reading "5" indicates the widest
bight.
TO CLEAN THE HOOK AND THE
THREAD WAYS
In order topreservethe life ofthe hook it is necessary
to clean the hook by means of a brush once or twice
daily depending on the materials used.
Two thread cutters "AF", Fig. 15 are mounted in the
thread ways by the rotary take-up to avoid wrapping
of the upper thread on the rotary take-up. After each
upper thread breakage the rotary take-up must be
checked for any remains of thread. These remains must
be removed before rethreading.
Figure 15
Caution: Attention to the above instructions will as
sure proper performance of the 457 G 1 machine.
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TIMING AND OTHER ADJUSTMENTS
The instructions on the following pages ore for Ad
justers and Mechanics only.
TO SET THE THREAD TAKE-UP SPRING
The thread take-up spring "AJ", Fig. 16, set at the
factory for normal sewing conditions,
must hove suffi
cient free movement to complete its action and should
be at rest against the upper end of the thread take-up
spring regulator "AH", Fig. 16as the pointof the needle
in its downward stroke is opprox. 1/16 inch = 1.6 mm
above the material. The action of the spring should be
sufficient to assure a light tension on the thread when
same passes around the bottom of the bobbin coseand
casts offthe hook point. By loosening the tension retain
ing screw "AG", Fig. 16 the tension complete can be
rotated until the spring regulator is in the desired posi
tion.
The tension of the thread take-up spring "AJ", Fig.16
is set by turning the tension stud "AK", Fig. 16 either
toward the right to increase it or toward the left to
decrease Itwith the tension screw "AG", Fig.16 securely
Figure 16
tightened. The tension on the thread take-up spring
should be sufficient to insure its action at top speed;
however, it should be light enough so that the spring
will move all the way down before the thread is pulled
over the tension wheel. The tension on the thread tok*
up spring requires different settings depending upo.
the size of the thread and other particular sewing con
ditions.
TO SET THE PRESSER BAR
In order to align the presser foot with the needle,
lower the presser foot onto the throat plate and loosen
the presser bar position guide pinch screw "AL", Fig.17
through the opening in the face plate. Then move the
presserfoot
into the desired position and securely tigh
ten the pinch screw. The presser bar lifter must be set
so that a presser bar lift of 9/32 inch = 7.15 mm is
obtained.
0
Figure 17
10
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