UnionSpecial 39500 MC Instruction sheet

FINES T QUALITY
STYLE
39500 MC
•
CATALOG
No.
®
LEWIS • COLUMBIA
CLASS 39500
INDUSTRIAL
SEWING
MACHINES
HI-STYLED HIGH SPEED
TWO OR THREE THREAD
HEMMER OR SERGER
DIFFERENTIAL FEED MACHINES
CHICAGO
From the library of: Superior Sewing Machine & Supply LLC

From the library of: Superior Sewing Machine & Supply LLC

August, 1969
Catalog No. 103 MC
(Supplement to Catalog No. 103 FA)
INSTRUCTIONS
FOR
ADJUSTING AND OPERATING
LIST OF PARTS
CLASS 39500
Style
39500 MC
First Edition
Copyright 1969
By
Union Special Machine Co.
Rights Reserved in All Countries
MACHINE COMPANY
INDUSTRIAL SEWING MACHINES
CHICAGO
Printed in U.S. A.
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IDENTIFICATION OF MACHINES
Each Union Special machine is identified by a Style number on a name plate on
the machine. Style numbers are classified as standard and special. Standard Style
numbers have one or more letters suffixed, but never contain the letter "Z".
Example: "Style 39500 MC". Special Style numbers contain the letter "Z". When
only minor chan g es are made in a standard machine~ a "Z" is suffixed to the stan-
dard Style number. Example: "Style 39500 MCZ".
Styles of machines sim il ar in construction are grouped under a Class number,
which differs from the Style number in that it contains no letters. Example: "Class
3 95 00".
APPLICATION OF CATALOG
This catalog is a supplement to Catalog No. 103 FA and should be used in con-
junction therewith. Only those parts used on Style 39500 MC, but not on Style 39500
FA are illustrated and listed at the back of this catalog. On the page opposite the
illustrat i on will be found a listing of the parts, with their part numbers~ description
and the number of pieces required. Numbers in the first column are reference
numbers only, and merely indicate the position of that part in the i llustration. Re-
ference numbers should never be used in orde r ing parts. Always use the part num-
ber listed in the second column.
This catalog applies specifically to the standard Style of machine as listed here-
in. It can also be applied with discretion to some Special Styles of machines in
Class 39500. References to directions, such as right, left~ front~ back, etc., are
given from the operator's position while seated at the machine. Operatin g di rection
of handwheel is away from operator.
STYLE OF MACHINE
Hi-Styled High Speed, Single Curved Blade Needle~ One Looper-One Spreader Two
Thread and Two Looper Three Thread Over seaming Machine. Differential Feed~
Trimming Mechanism with Spring Pressed Lower Knife, Automatic Lubricatin g
System.
39500 MC Light to medium duty~ two way combination machine, for two or three
thread blind hemming or serging small diameter light weight rayon~ s ilk, wool~
cotton~ flat and ribbed knit materials. Seam specifications 503 EFc-1~ or
505 EFd-1. Standard seam width for hemming 1I8 inch and for ser g in g 3I 16
inch. Stitch range 8 to 30 per inch. Cam adjusted main and different ial feeds.
Maximum recommended speed 7 000 R. P.M.
OILING
CAUTION! Oil was drained from machine when shipped~ so reservoir must be
filled before beginning to operate. Oil capacity of Class 39500 is si?E, ounces. A
straight mineral oil of a Saybolt viscosity of 200 to 250 seconds at 100 Fahrenheit
should be used.
Machine is filled with oil at sprin g cap in top cover. Oil level is checked at
sight gauge on front of machine. Red bulb on oil level indicator should show between
gauge lines when machine is stationary.
Machine is automatically lubr i cated. No oil ing is necessary, other than keepin g
main reservoir filled. Check oil daily before the morning start; add oil as required.
The oil drain plug screw is located at back of machine near bottom ed ge of base.
It is a magnetic screw desi g ned to accumulate possible foreign materials which may
have entered the crank case. It should be removed and cleaned periodically.
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NEEDLES
Each Union Special needle has both type and size number. The type number
denotes the kind of shank, point, length, groove, finish and other details. The size
number, stamped on the needle shank, denotes largest diameter of blade, measured
in thousandths of an inch, midway between shank and eye. Collectively, type and
size number represent the complete symbol which is given on the label of all needles
packaged and sold by Union Special.
Class 39500 machines use a curved blade needle. The standard recommended
needle for Style 39500 MC is Type 154 GAS. Below is the description and sizes
available of the recommended needle.
Type No. Description and Sizes
154 GAS Round shank, round point, curved blade, standard length, single groove,
struck groove, spotted, chromium plated and is available in sizes 022,
025, 027, 029, 032, 036, 040, 044, 049, 054.
To have needle orders promptly and accurately filled, an empty package, a
sample needle, or the type and size number should be forwarded. Use description
on label. A complete order would read: "1 000 Needles, Type 154 GAS, Size 027".
Selection of proper needle size is determined by size of thread used. Thread
should pass freely through needle eye in order to produce a good stitch formation.
Success in the operation of Union Special machines can be secured only by use
of needles packaged under our brand name, ~ . which is backed by a
reputation for producing highest quality needles in materials and workmanship for
more than three-quarters of a century.
CHANGING NEEDLES
Release pressure on presser foot by turning presser foot release bushing (AG,
Fig. 1 or 1A) and swing presser arm (U) out of position. Turnhandwheel in operating
direction until needle is at its lowest point of travel. Using hexagonal socket wrench
No. 21388AU, furnished with machine, loosen needle clamp nut about 1/4 turn.
Again turn handwheel until needle is at high position; withdraw needle.
To replace needle, leave needle holder at high position and, with the flat to the
left, insert needle in holder until it rests against stop pin. Keeping needle in this
position, turn handwheel until holder is again at its low point of travel; then tighten
nut. Return presser arm (U) to position and re-lock presser foot release bushing
(AG).
THREAD STAND
After thread comes from cones on cone support (A, Fig. 1 or 1A) it is brought
up through the back hole of thread eyelet (B), then down through the front hole of
thread eyelet. Next, the upper looper thread (505 STITCH only) and the needle
thread are threaded through the upper hole of tension thread guide (C)from front to
back, and then through the lower hole, from back to front. The lower looper thread
is threaded through the upper hole of the tension thread guide (C) from back to front,
through the middle hole from front to back and then through the lower hole from back
to front. All threads then continue between the tension discs (J), through tension
post slot (K) in tension post (G) and on through eyelets in front thread guide (M).
NOTE:
Refer to Fig. 1 for threading 503 stitch or Fig. 1A for threading 505
stitch.
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li] Tension Nut
~~ Thread Eyelet
~~ Tension Spring Fer~
II Tension Spring ---,~/ nlh~l\d:\\
[!] Tension Post
IIJ spring Shield _
OTension Discs < .
P!.ll Tension Post Slot . '...... ... --~;:::.:"
.. ••. ·-~"">"
II Tension Disc Felt . j
f1J Front Thread
I:J Lower Looper Thread
BJ Fabric Guard
D) Presser
Fig. 1
6
0
Presser Foot
~~~ Release Bushing
Top Cover
...... Needle Thread Eyelet
Upper Looper
Thread Tube Assembly
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li] Te ns ion Nut
(I Ten sio n Spring F e r ~
IJ Tension Spring~ r..-~:=-h'\.1
[!] Tension Post
IIJ spring Shield
gTension
Discs -<: .
~~ T e nsion Post Slot ·.
II Tension Disc Felt ·.
[i Tension Thread Guide
f1J Front Thread Guide
~~~ Upper Looper Thread Eyelet
I:J Lower Looper Thread Eyelet
D
Frame Looper
Thread Guide
m Presser Arm
7
Cone Support
Top Cover
M~:. Needle Thread Eyelet
Upper Looper
Thread Tube Assembly
Upper Looper
Lower Looper
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THREADING
Only parts involved in threading are shown in threading diagram (Fig. 1 and 1A).
Parts are placed in their relative positions for clarity.
It will simplify the threading of these machines to follow the recommended se-
quence of threading the lower looper first and the needle second for the 503 stitch.
The recommended sequence of threading the 505 stitch is lower looper first~ upper
looper second and the needle third.
Before beginning to thread, swing cloth plate open and turn handwheel in opera-
ting direction until needle (X) is at high position. Now release pressure on presser
foot by turning presser foot release bushing (AG) and swing presser arm (U) out of
position.
Be sure the threads, as they come from the tension thread guide (C)~ are be-
tween tension discs (J) and in tension post slots (K) in tension posts (G). The tension
posts should be positioned so the tension post slot will be at the approximate angle
for the different threads as indicated in Fig. 1 and 1A.
TO THREAD THE LOWER LOOPER
Double end of thread and lead it through the right eyelet of front thread guide
(M, Fig. 1 or 1A). Then lead thread through both eyes of lower looper thread eye-
let (R~ Fig. 1 or 1A) from right to left. NOTE: thread must pass in front of looper
thread pull-off (AF). Lead thread behind fabric guard (S) and through frame looper
thread guide {T). Turn handwheel in operating direction until heel of lower looper
(V) is all the way to the left, then thread through both eyes from left to right. Left
eye of lower looper can be threaded easily if tweezers are in left hand.
TO THREAD THE UPPER LOOPER (505 STITCH ONLY)
Double end of thread and lead it through the left eyelet of front thread guide (M~
Fig. 1A). Turn handwheel until point of upper looper (W~ Fig. 1A) is all the way
to the left. Lead thread through auxiliary looper thread eyelet (P) from back to
front, then through both eyes of upper looper thread eyelet {N) from left to right.
NOTE: Thread must pass in front of looper thread pull-off (AF).
After pulling up upper looper thread tube assembly (AA), lead thread under neck
of top cover casting and down through thread tube assembly (AA). Pull thread out
bottom of tube; push tube down and then insert thread throu gh the eye of upper
looper from front to back.
TO THREAD THE NEEDLE
Double end needle thread and lead it through middle eyelet of front thread g uide
(M, Fig. 1 or 1A). Then turn handwheel in operating direction until needle (X) is
at its highest position. Insert needle thread from right to left, through both e yes of
needle thread eyelet (AD), under neck of top cover casting; then down throu gh hole
in top cover needle thread eyelet (AC). Thread needle from front.
THREAD TENSION
The amount of tension on the needle and looper threads is regulated by tension
nuts (D, Fig. 1 or lA). Tension on threads should be only enough to secure proper
stitch formation.
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PRESSER FOOT PRESSURE
Sufficient presser foot pressure to feed work uniformly
should be maintained. Should it be necessary to increase
or decrease the amount of pressure on presser foot~
loosen lock nut (A. Fig. 2) and turn adjusting screw (B).
Adjusting screw has a right hand thread. so tightening in-
creases pressure. loosening decreases pressure. When
pressure adjusting screw (B) has been properly set. tighten
lock nut (A). With presser foot resting on throat plate.
position locking nut (C) so that its under surface is ap-
proximately 1I32 inch to 1I 16 inch from the top surface of
adjusting screw (B). Set cap (D) against locking nut (C).
Fig. 2
FEED ECCENTRICS
Feed eccentrics used in Style 39500 MC machines have been selected to produce
approximately 14 stitches per inch. It will be noted that the part number of the main
feed eccentric is No. 39540 B-14. while that of the differential feed eccentric is No.
39540 B-8. Minor numbers of the part symbol indicate approximately the number
of stitches obtainable when using that eccentric. Unless otherwise specified. ma-
chine will be shipped with above combination of eccentrics.
Generally speaking, differential (right hand) feed eccentric determines number
of stitches produced; main (left hand) feed eccentric is selected in relation to degree
and direction of stretch of material being sewn. or type of operation.
Following stitch number feed eccentrics are available under No. 39540 B-4. -5.
-6.-7. -8. -9. -10. -11. -12,-13. -14. -15. -16. -18,-20. -22. -24. -26. -28. -30. -32. -34.
-36,-40. Only two eccentrics are supplied with each machine. Additional eccentrics
may be ordered separately. To order an eccentric. use No. 39540 B with a minor
number suffixed to indicate number of stitches desired. Example: "39540 B-8".
Fi g. 3
ASSEMBLING AND ADJUSTING SEWING PAR TS
Before assembling and adjusting sewin g parts.
remove cloth plate. fabric guard, chip guard, upper
knife assembly~ lower knife holder assembly. hem-
ming guide assembly; then follow this suggested se-
quence.
SETTING THE NEEDLE
With throat plate assembled in position. ne edle
should center in the front end of needle slot. When
needle is at high position. needle point should be set
112 inch above throat plate (Fig. 3). To ali gn ne edle
or set the height above throat plate. mov e ne edle
driving arm (A, Fig. 3) by loosening clamp screw
(B). Remove throat plate. after needle has been set
properly and clamp screw (B) has been tightened.
At this point. insert lower looper (A~ Fig. 4) into
bar (B). With lower looper at left end of its stroke~
set looper point 3I32 inch from center of needle (Fig. 4)
using looper gauge No. 2122 5-3 I 32. Do not have lower
looper deflecting needle. Tighten nut (C). Now assem-
ble differential (front) feed dog.
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Fig. 4
SETTING THE REAR NEEDLE GUARD
Set rear needle guard (A, Fig. 5) as high as
possible, without interfering with either lower
looper or movement of lower knife holder, but still
in position to deflect needle forward • 002 - • 004
inch. Screw (B) is used to set rear needle guard.
Make sure there is no interference between rear
needle guard and lower looper.
SETTING THE LOWER LOOPER
Now finish lower looper adjustment. As lower
looper moves to the right, its point should be set into the needle scarf (A. Fig. 6)
u?til the needle springs forward from rear guard surface another . 002 - • 004 inch.
SETTING THE FRONT NEEDLE GUARD
Assemble front needle guard (C. Fig. 5). When lower
looper is springing needle off back guard. set front needle
guard as close as possible to needle without touching. Screw
(D) is used to adjust and set front needle guard. After this
setting. make sure there is no interference between needle
guard and differential feed dog.
SETTING THE UPPER LOOPER OR SPREADER
Insert upper looper (A. Fig. 7) or
upper spreader in its holder. Screw
(B) holds the upper looper or spreader
in its holder. and permits the upper
looper or spreader to be pushed in or
out. or turned around its shank. Insert
upper looper or spreader holder into
shaft, if not already in place. Screw
(C. Fig. 7) on clamp collar holds upper
looper or spreader holder in the shaft,
and allows holder to be rotated or ad-
justed laterally.
Fig. 5
Fig. 6
Preliminary Setting: When the upper looper or spreader is at
the right end of its stroke, the upper looper or spreader holder should be set to
position the upper looper or spreader shank slightly back of vertical (Fi g. 7). Top
end of the upper looper or spreader shank should extend 1I32 to 1I 16 inch above the
upper looper or spreader holder (Fig. 7).
Fig. 7
As the upper looper or spreader moves from right to left.
the point of the upper looper or the Vee notch of the spreader
should pass just behind the eye of the lower looper. with
approximately • 002 inch clearance between the upper looper
or spreader and the lower looper (Fig. 8).
Turn the handwheel until the upper looper or spreader is
at the left end of its travel. At this position. the point of the
upper looper or the lower point of the upper spreader should
extend about 5132 inch to the left of the centerline of the needle
and also be 15 I32 inch above the top of the throat plate (Fig. 9).
If resetting is necessary. do it by moving the upper looper or
spreader holder (A, Fig. 9).
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