UnionSpecial 39500 Series Instruction sheet

FIN E ST QUALITY
ST Y LE
395 0 0MY
CATALOG
No.
103MY
®
INDUSTRIAL ·
SEWING
LEWIS • COLUMBIA
MACHINES
CLAS S 39500
HI-STYLED HIGH SPEED
THREE THREAD PLAIN FEED
MACHINES
FOR
HEMMING MESH BAGS
CHICAGO
From the library of: Superior Sewing Machine & Supply LLC

Catalog No. 103 MY
(Supplement to Catalog No. 103 FJ)
INSTRUCTIONS
FOR
ADJUSTING AND OPERATING
LIST OF PARTS
CLASS 39500
Style
39500 MY
First Edition
Copyright @ 1972
by
Union Special Machine Co.
Rights Reserved in All Countries
MACHINE COMPANY
INDUSTRIAl SEWING MACHINES
CHICAGO
Printed in U.S . A.
2
October, 1972
From the library of: Superior Sewing Machine & Supply LLC

IDENTIFICATION OF MACIDNE
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 MY". Special Style numbers contain the letter "Z". When
only minor changes are made in a standard machine, a "Z" is suffixed to the stand-
ard Style number. Example: "Style 39500 MYZ".
Styles of machines similar in construction are grouped under a Class number
which differs from the Style number in that it contains no letters. Example: "Class
39500".
APPLICATION OF CATALOG
This catalog is a supplement to Catalog No. 103 FJ and should be used in con-
junction therewith. Only those parts used on Style 39500 MY but not on Style 39500 FJ
are illustrated and listed at the back of this catalog. On the page opposite the
illustration 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 illustration.
Reference numbers should never be used in ordering parts. Always use the part
number listed in the second column.
This catalog applies specifically to the standard Style of machine as listed
herein. 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. Operating direction
of handwheel is away from operator.
STYLE OF MACIDNE
Hi-Styled High Speed Single Curved Blade Needle, Two Looper, Three Thread Seam-
ing Machine. Plain Feed, Automatic Lubricating System.
39500 MY Medium to heavy duty machine for hemming 5 to 25 pound paper, cotton
or synthetic mesh bags. Will turn up from 3/4 inch to 1 1/4 inch of two plies
of material and finish into a tight roll approximately 1/4 inch in diameter .
Seam Specification 504-SSp-1 modified; stitch range, 4-20 per inch, cam
adjusted feed. Maximum speed 6500 R. P.M. Maximum recommended speed
5500 when sewing mesh bags.
OILING
CAUTION! Oil was drained from machine when shipped, so reservoir must be
filled before beginning to operate. Oil capacity of Class 39500 is six ounces. A
straight mineral oil of a Saybolt viscosity of 90 to 125 seconds at 100° Fahrenheit
should be used.
Machine is filled with oil at spring 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 lubricated. No oiling is necessary, other than keeping
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 edge of bas0.
It is a magnetic screw designed to accumulate possible foreign materials which may
have entered the crank case. It should be removed and cleaned periodically.
3
From the library of: Superior Sewing Machine & Supply LLC

NEEDLES
Each Union Special needle has both type and size number. The type number de-
notes 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 Spec i al.
Class 39500 machines use a curved blade needle. The standard recommended
needle for Style 39500 MY is Type 154 GAS. Below is the description and sizes
available of the recommended needle.
Type No.
154 GAS
Description and Sizes
Round shank, round point, curv ed 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, 060.
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:
11
1000 Needles, Type 154 GAS, Size 060
11
•
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 are-
putation for producing highest quality needles in materials and workmanship for
more than three-quarters of a century.
CHANGING NEEDLE
Release pressure on presser foot by turnin g presser foot release bushing (AG,
Fig. 1) and swing presser arm (U) out of position. Turn handwheel in operatin g
direction until needle is at its lowest point of travel. Using hexagonal socket wrench
No. 21388 AU, 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 hi gh 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 aga in at its low point of travel; then ti g hten
nut. Return presser arm (U) to position; re-lock presser foot release bushing (AG).
THREAD STAND
After thread comes from cones on cone support (A, Fig. 1), it is brought up
through back hole of thread eyelet (B), then down through the front hole of thread
eyelet. Next it is threaded through the upper holes of tension thread guide (C) from
front to back and then through the lower holes from back to front. It should be noted
that the lower looper thread is threaded through the tension thread guide (C), first
through the upper hole back to front, second through the middle hole front to back
and third through the lower hole back to front. All threads then continue between the
tension discs (J), through tension post slot (K) in tension post (G) and on through
front thread guide (M).
4
From the library of: Superior Sewing Machine & Supply LLC

(;] Tension Nut
IJ Tension Spring
II Tension Spring
[!]Tension Post
ll) spring Shield
nTension Disc
(I Tension Post
II Tension Disc
fiJ Front Thread Guide
13 Lower Looper Thread Eyelet
- Fabric Guard Bracket
D Frame Looper
Thread Guide
m Presser Arm
Fig. 1
~~ Thread Eyelet
5
From the library of: Superior Sewing Machine & Supply LLC

THREADING
Only parts involved in threading are shown in t hreading diagram (Fig. 1). Parts
are placed in their relative positions for clarity.
It will simplify threading this machine to follow recommended sequence of
threading lower looper first, upper looper second, and needle third.
Before beginning to thread, swing cloth plate open, turn handwheel in operating
direction until needle (X) is at high position, release pressure on presser foot by
turning presser foot release bushing (AG); and swing presser arm (U) out of position.
Be sure threads, as they come from the tension thread guide (C), are between
tension discs (J) and in diagonal slots (K) in tension posts (G).
TO THREAD LOWER LOOPER
Double end of thread and lead it through both eyes of lower looper thread eyelet
(R, Fig. 1) from right to left. Note: thread must pass in front of looper thread pull-
off (AF). Lead thread behind fabric guard (S) and through eyelet hole of frame looper
t hread 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 UPPER LOOPER
Turn handwheel until point of upper looper (W) is all the way 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, then insert thread
through upper looper eye from front to back.
CAUTION! Be sure upper looper thread is under lower looper thread when
passing from tube assembly to upper looper eye.
TO THREAD THE NEEDLE
Turn handwheel in operating direction until needle (X, Fig. 1) is at its highest
position. Insert needle thread from right to left, through both eye s of needle thread
eyelet (AD), under neck of top cover casting; then down through hole in top cover
needle thread eyelet (AC). Thread needle from front.
THREAD TENSION
The amount of tension of needle and looper thread is
regulated by three knurled tension nuts (D, Fig. 1). Tens-
ion on threads s hould be only enough to secure proper
stitch formation.
PRESSER FOOT PRESSURE
Sufficient pres s er foot pressure to feed work uniformly
should be maintained. Should it be necessary to increase
or decrease amount of pressure on pres s er foot, loosen
lock nut (A, Fig. 2) and turn adjusting screw (B). Adjusting
screw has a right hand thread so tighten i ng increases
pressure, loosening decreases pressur e. Wh en pressur e
6
Fig . 2
From the library of: Superior Sewing Machine & Supply LLC

PRESSER FOOT PRESSURE (Continued)
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 approxi-
mately 1/32 inch to 1/16 inch from the top surface of adjusting screw (B). Set cap
(D) against locking nut (C).
FEED ECCENTRICS
Feed eccentric used in this machine has been selected to produce approximately
5 stitches per inch. It will be noted that the part number of feed eccentric is No.
39540 B-5. Minor number of the part symbol indicates approximately the number of
stitches obtainable when using that eccentric. Unless otherwise specified, machine
will be shipped with above eccentric.
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 one eccentric is 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-5'
1•
ASSEMBLING AND ADJUSTING SEWING PARTS
Before assembling and adjusting sewing parts, remove cloth plate, fabric
guard. chip guard, then follow this suggested sequence:
SETTING THE NEEDLE
With throat plate assembled in position. needle
should center in the front end of needle slot. When
needle is at high position, needle point should be
set 1/2 inch above throat plate (A. Fig. 3). To align
needle or set the height above the throat plate, move
needle driving arm (B. Fig. 3) by loosening clamp
screw (C). Remove throat plate.
Fig. 3
If needle thread cam pull-off (A, Fig. 4) over-
laps looper thread pull-off (B). separate by moving looper thread pull-off back.
When retightening looper pull-off screw. be sure to take up end play in needle
driving arm.
At this point, insert lower looper (A, Fig. 5)
into bar (B). With lower looper at left end of its
stroke, set looper point 3/32 inch from center of
needle(Fig. 5). usingloopergauge No. 21225-3/32.
Do not have lower looper deflecting needle. Tighten
nut (C).
Now assemble the main feed dog.
SETTING THE REAR NEEDLE GUARD
Set rear needle guard (A. Fig. 6) as high as
possible, without interfering with lower looper, but
still in position to deflect needle forward . 00 2-. 004
inch. Screw (B) is used to set rear needle guard.
Make sure there is no interference between rear
needle guard and lower looper.
7
Fig. 4
From the library of: Superior Sewing Machine & Supply LLC

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. 7) until the needle springs forward
from rear guard surface another . 002-. 004 inch.
SETTING THE FRONT NEEDLE GUARD
Assemble front needle guard (C, Fig. 6).
When lower looper is springing needle off back
guard, set front needle guard as close as possi-
ble to needle without touching. Screw (D) is used
to adjust and set front needle guard. After this
setting make sure there is no interference be-
tween needle guards and main feed dog.
SETTING THE UPPER LOOPER
Fig. 5
Insert upper looper (A, Fig. 8) in its holder. Screw (B, Fig. 8) holds upper
looper in its holder and permits it to be pushed in or out or turned around its shank .
Fig. 6
Insert upper looper holder into upper
looper shaft, if it is not already in
place. Screw (C~ Fig. 8) on clamp
holds the upper looper holder in the
shaft. Locate upper looper in its
holder so that the shank extends 1/16
to 3/32 inch beyond holder (Fig. 8).
When t he upper looper is at the
ri g ht end of its stroke upper looper
holder should be set to position upper
looper shank about vertical (Fig. 8).
Be sure there is a clearance between
heel of looper and the casting. By
adjusting looper holder in or out of Fig. 7
upper looper shaft and by turning the
looper around its shank, set upper looper point to cross
lower looper to the left of the lower looper eye with . 002 to
. 004 clearance (Fig. 9).
As the upper looper moves toward the top of its stroke,
the heel of the upper looper should pass behind the lower
looper head with 1/32 to 1/16 inch clearance.
Turn the handwheel until the upper looper is at the left end of its travel. At
this position, the point of the upper looper should extend 9/64 inch to the left of the
centerline of the needle and should be 17/32 inch above the top of the thro at plate
(Fig. 10). If resetting is necessary, do it by moving the upper looper holder
(A, Fig. 10).
For example, the 17/32 inch dimension is increased by turning upper looper
holder counterclockwise, looking from left end of machine; the 9/64 inch dimens-
ion is increased by pulling upper looper holder to the left, out of upper looper shaft.
After these changes are made, it may be necessary to turn upper looper around
its shank slightly to maintain the condition shown in Fig. 9.
8
From the library of: Superior Sewing Machine & Supply LLC

SETTING THE UPPER LOOPER (Continued)
When the correct setting is obtained, it can be checked quickly as follows: As
the upper looper is moving to the right and the upper looper eye centers on the
needle, the eyes of the upper looper and needle should align exactly (Fig. 11).
Check setting to avoid interference
between upper looper and needle on
needle downstroke. If needle rubs the
back of upper looper, pull looper out
of its holder slightly and rotate looper
a short distance counterclockwise,
looking from left end of machine. Reset
to maintain dimensions of Figs. 9, 10,
11.
SETTING THE FEED DOG
Assemble the throat plate, if not
already on the machine. The feed dog
Fig.
8 (A,
Fig. 12) should be set level with Fig.
9
the top surface of the throat plate (B),
at the time the teeth first appear above the throat plate. The leveling of the feed dog
can be accomplished by rotating the feed tilting adjusting pin (C, Fig. 12). This
pin raises and lowers the back end of the feed bar. Screw (D) locks the feed tilting
adjusting pin in place and should be loosened before making an adjustment to the pin.
Now set the feed dog at its highest point of travel, that is, the feed dog should rise
the depth of a full tooth above the throat plate.
SETTING THE STITCH LENGTH
Length of stitch is determined by feed eccentric used.
Note that the part number of the feed eccentric used in this
machine is No. 39540 B-5.
In assembling the feed eccentric (A, Fig. 13), be sure
the hub and oil groove is to the left. Beveled edge of feed
eccentric spacer (B) should also be to the left side, so the
undercut on the spacer will be over the hub on the feed
eccentric. Be careful not to damage shaft or key. Assemble
washer (D) and tighten nut (C) securely.
To change feed eccentric, remove nut (C), washer (D)
and feed eccentric spacer (B). Turn handwheel in operating
Fig. 10
direction until key slot in eccentric is toward the front. Using hooked eccentric
extractor (E), supplied with machine, reach behind eccentric as shown and withdraw
eccentric. It may be necessary to move handwheel back and forth slightly during
extraction.
SETTING THE PRESSER FOOT
Assemble the presser foot to presser arm. With needle in high position, swing
presser arm into sewing position and set the presser foot to align needle hole
(front and back) and flat on throat plate. The front edge of needle hole in presser
foot must be aligned with front edge of needle hole in throat plate. It is also import-
ant that the bottom of the presser foot be flat on the throat plate. If necessary,
presser foot can be realigned with throat plate slots by shifting the foot lifter lever
shaft (H, Fig. 14). To move the shaft, loosen collar screws (B, Fig. 14) and clamp
screw (G) and then shift the foot lifter lever shaft to the left or right as required.
Retighten collar screws and clamp screw.
9
From the library of: Superior Sewing Machine & Supply LLC

SETTING THE PRESSER FOOT (Continued)
The foot lifter lever arm (A, Fig. 14) and the collar (B) secure the shaft. Be
sure the presser arm does not bind and rise when presser foot release bushing is
unlocked.
Adjust lifter lever stop screw (C) so that presser foot
can be raised no higher than upper looper will permit: then
lock the nut (D). There should be from 1/16 to 1/8 inch free
motion of foot lifter lever before the presser foot begins to
rise. This adjustment should be made with screw (E) and
locked with nut (F). Re-assemble the chip guard, fabric
guard and cloth plate.
STARTING TO OPERATE
Be sure machine is threaded according to threading
diagram (Fig. 1). With thread tensions light, set looper
thread eyelets (N and R) about horizontal and in the middle
of their front to back locations. Operate machine slowly,
without presserfoot in place, to make surethat chain forms
and moves off the tongue freely. Swing presser foot into
position, insert material, and sew slowly.
NEEDLE THREAD CONTROL
Fig. 11
While sewing on material, check needle thread control as follows: Usually all
needle thread is drawn on needle down stroke. At top of needle stroke, thread should
be just tight enough to feed chain off stitch tongue. Stitch tends to pull down slightly
if excessive thread is pulled on the up stroke. With needle at bottom of stroke, posi-
tion needle thread eyelet (AD, Fig. 1) so that needle thread cam pull-off (AE) just
contacts needle thread.
It is desirable to adjust the needle
thread pull-off eyelet well-forward
(toward the operator) to delay, slight-
ly, the tightening of the needle thread.
LOWER LOOPER
THREAD CONTROL
With material under presser foot,
set lower looper thread eyelet (R,
Fig. 1) back far enoughso thread is a
little slack when looper thread pull-off
(AF) reaches its most rearwardposi-
tion. Looper thread pull-off (AF) is
Fig. 12 set about 1/8 inch distance behind
needle thread cam pull-off (AE) .
Frame looper thread guide (T) should be set with its eyelet approximately 1/8 inch
to right of lower looper (V) heel eyelet at the time lower looper is at extreme left
end of its travel.
While sewing on material, check drawing off of looper thread as follows: A
portion of lower looper thread should be drawn through the tension before lower
looper thread comes off upper looper. To increase amount of thread drawn through
the tension while lower looper thread is on upper looper, move lower looper thread
eyelet (R) down, keeping the same amount of pull-off action.
10
From the library of: Superior Sewing Machine & Supply LLC