UnionSpecial 39500W Series Instruction sheet

F INEST QUALITY
STYLES
3 9500W
CATALOG
No.
103W
®
INDUSTRIAL
SEWING
LEWIS • COLUMBIA
MACHINES
CLASS 39500
STREAMLINED
HIGH SPEED OVERSEAMERS
MACHINE COMPANY
CHICAGO
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Catalug No . 103 W
I ~S TRU C TIONS
FOH
ADJUSTI~G .t \ ~D OPER A TI N G
LIST OF P A HTS
CL \SS 39500
Style
3 9 500 w
First Edition
Copyri g ht 1958
by
Un'on Special M achi ne Co.
Ri g hts Reserv e d in A ll Countri e s
MACHINE COMPANY
INDUSTRIAL SEWING MACHINES
CHICAGO
Printed in U.S. A.
July, 1971
From the library of: Superior Sewing Machine & Supply LLC

IDENTIFICATION OF MACHINE
Each Union Special machine carries a Style number which is stamped in the 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 W". 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 WZ".
Styles of machines similar in construction are grouped under a Class number,
which contains no letters. Example: "Class 39500 ".
APPLICATION OF CATALOG
This catalog is a supplement to Catalog No. 103 S and should be used in con-
junction therewith. Only those parts which are used on Style 39500 W and not on
Styles 39500 A, B or P are illustrated and listed at the back of the book.
This catalog applies specifically to the standard Styles of machines as listed
herein. It can also be applied with discretion to some special machines in Class
39500. All references to directions, such as right and left, front and back, etc.,
are taken from the operator's position while seated at the machine. Operating direct-
ion of handwheel is away from operator.
STYLES OF MACHINES
Two Needle, Two Looper, Four Thread, Overseaming Machine. Differential Feed,
Trimming Mechanism with Spring Pressed Lower Knife, Automatic Lubricating
System.
39500 W For seaming light to heavy knitted and woven fabrics with a modified safety
stitch. For operations on pajamas, bathing suits, house dresses, children's
wear, ladiee.' undergarments, and similar articles, standard width of seam from
left needle 17/64 inch, stitch range 6 to 20 per inch, standard setting 10 per
inch.
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 tip of oil 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.
Drain plug screw is located at back of machine near bottom edge of base. 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.
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 Special.
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NEEDLES (Continued)
Style 39500 W uses curved blade needles. The standard needle for this style is
Type 154 GAS. It is a curved blade, standard length, single groove, shallow spot,
long tapered point, struck groove, chromium plated 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: "1000 Needles, Type 154 GAS, Size 036".
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 re-
putation for producing highest quality needles in materials and · workm a nship for
more than three-quarters of a century.
CHANGING NEEDLES
Release pressure on presser foot by turning presser foot release bushing (S,
Fig. 1) . and swing presser arm (H) out of pos:l.tion. Turn handwheel in operating
direction until needles are at their 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 needles are at their high position; withdraw needles.
To replace needles, leave needle holder at high position and, with the flats to
the left, insert needles in holder, one on each side of spacer washer, until they
rest against stop pin. Keeping needles in this position, turn handwheel until holder
is again at its low point of travel; then tighten nut. Return presser arm (H) to
position; re-lock presser foot release bushing (S).
THREAD STAND
After threads come from cones on thread stand (Z, Fig. 1), they ar e brought
up through back eyelets, then down through front eyelets (Y) and throu gh the adjust-
able thread guide. Next, they are threaded through each pair of holes in tension
thread guide wire (A), down through right hand hole and up throu gh left ha nd hole.
Then thread continues between tension discs (U), through slot (T), and on through
thread guide (B).
THREADING
Only parts involved in threading are shown in threading dia g ram (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 needles third.
Before beginning to thread, swing cloth plate open, turn handwheel in operatin g
direction until needles (L) are at high position, release pressure on presser foot by
turning presser foot release bushing (S); and swing presser arm (H) out of position.
Be sure threads, as they come from the tension thread guide, are between
tension discs (U) and in diagonal slots (T) in tension posts (V).
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Figure 1
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5
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TO THREAD LOWER LOOPER
Double end of thread and lead it through both eyes of lower looper thread
eye let (E, Fig. 1) from right to left. Note: thread must pass in front of looper
thread pull-off (R). Lead thread behind fabric guard (F) and through frame
looper thread g uide (G). Turn handwheel in operating direction until heel of
lower looper (J) is all the way to the left; then thread through both eyes from
left to right. Left eye of lower looper c an be threaded easily if tweezers are
in left hand.
TO THREAD UPPER LOOPER
Turn handwh e el until point of upper looper (K) is all the way left. Lead
thread through auxiliary looper thread eyelet (D) from back to front, then
throu gh both eyes of upper looper thread eyelet (C) from left to ri ,) 1t. Note:
thread must pass in front of looper thread pull-off (R). After pulling up upper
looper thread tube assembly (M), lead thread under neck of top cover casting
and down throu g h thread tube assembly (M). Pull thread out bottom of tube;
push tube down, then insert thread throu gh upper looper eye from front to back.
CAUTION! Be sure upper looper thread is under lower looper t hread when
passing from tube assembly to upper looper eye.
TO THREAD THE NEEDLE
Turn handwheel in opera ti ng direction until needles (L, Fig. 1) are at their
highest position. Insert both needle threads from right to left, through both
eyes of needle thread eyelet (P), under neck of top cover casting; then down
through hole in top cover needle thread eyelet (N). Thread needles from front.
THREAD TENSION
The amount of tension on needle and looper threads is regulated by four
knurled tension nuts (X, Fig. 1). Tension on threads should be only enough
to secure proper stitch formation.
PRESSER FOOT PRESSURE
Sufficient pressure to feed work uniformly should
be maintained. Should it be necessary to increase or
decrease amount of pressure on presser foot, loosen
lock nut (A, Fig. 2) and turn adjustin g screw (B).
Adjustin g screw has a ri g ht hand thread; so tightening
increases pressure, loosening decreases pressure.
When pressure adjusting screw (B) has been properly
set, tighten lock nut (A). With presser foot resting l ~
on throat plate, position locking nut (C) so that its
under surface is approximately 1I 32 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 this machine have been selected to produce approx-
imately 10 stitches per inch. It will be noted that the part numbers of feed
eccentrics are N o. 39540-10 for the differential feed and No. 39540-12 for the
main feed. Minor numbers of the part symbols indicate approximately the
number of stitches when using that eccentric. Unless otherwise specified,
machine will be shipped with above combination of eccentrics.
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FEED ECCENTRICS (Continued)
Following stitch number feed eccentrics are available under No. 39540- 4,
5, 6, 7, 8, 9, tO, II, 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 eccen-
trics may be ordered separately. To order an eccentric, use No. 39540 with
a minor number suffixed to indicate number of stitches desired, Example:
"39540-12
11
•
ASSEMBLING AND ADJUSTING SEWING PARTS
Before assembling sewing parts, remove cloth plate, fabric guard, chip
guard, upper knife assembly, lower knife holder assembly; then follow this
suggested sequence:
Fig. 3
Fig. 5
SETTING THE NEEDLE
With the throat plate in position, needles should center
in the front end of needle slots. When ne eclles are at high
p o s it ion, needle points
should be set 15/32 inch
above throat plate (Fig. 3).
Move needle driving arm
(A, Fig. 3), by loosening
clamp screw (B). Remove
the throat plate.
If needle thread cam
pull-off(A, Fig. 4) overlaps
looper thread pull-off (B),
separate by moving looper
thread pull-off to back.
When re-tightening looper
pull-off screw, be sure to
take up end play in needle
driving arm.
At this point, in-
sert lower looper (A,
Fig. 6) into bar (B).
With the lower looper
at the left end of its
stroke, set point 1 I 16
inch from center of
left needle (Fig. 6),
using looper gau ge
No. 21225-1/16.
Fig. 4
Fig. 6
SETTING THE REAR NEEDLE GUARD
Set rear needle g uard (A, Fig. 5) as high as pos-
Slble, without interfering with either lower looper or
movement of lower knife holder, but still in position
to deflect needles forward . 002-. 004 inch. Screw
(B) is used to set rear needle g uard. Make sure
there is no interference between rear needle gu a rd
and lower looper.
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SETTING THE LOWER LOOPER
Now, finish lower looper adjustment. As lower looper
moves to the right, its point should be set into the scarf
of the left needle (A, Fig . 7) until the needles s pring for-
ward from rear guard s urf a ce another • 002-.004 inch.
SETTING THE FRONT NEEDLE GUARD
Assemble front needle guard (C, F ig. 5). When lower
looper is springing needles off ba ck g uard, set front needle
guard as closely as possible to needle s without touching.
Use screw (D) to adjust and s et f ront ne edle g uard. After
setting, make sure there is no interferenc e between needle
guards and different i al fe ed do g.
Fi g. 7
SETTING THE UPPER LOOPER
Fi g. 8
Fig. 9
Insert upp er loop er (A, Fig. 8) in its holder. Screw
(B) hold s upper loop er in its holder, and permits it to be
pushed in or out or turn ed a round its shank. Ins e rt upper
looper holder i nto upper looper shaft, if it is not already
in plac e. Scr ew (C) on clamp holds the upper looper holder
in the shaft. Loc ate upp er looper in its holder so that the
shank extends 1/16 to 3/32 inch beyond holder.
Wh en th e upperlooper is at the right end of its stroke,
upper loop er holder should be set to pos i tion upper looper
shank back of ve rtical (Fig. 8).
By adjusting looper holder in or
out of upper looper sha ft and byturnin g
the looper around its shank, set upper
looper point to cross lower looper to
the left of the lower looper eye with
0. 002 to 0. 004 clearance (Fig. 9).
Next, turn the handwheel until up-
per looper is at the left end of its
travel. Check dimensions of upper
looper point with respect to the right
needle and throat plate (Fig. 10). If
resetting is necessary, do it by movin g
the upper looper holder (A, Fig. 10).
Figure 10 represents the dimensional
setting.
Fi g. 10
Dimension 33/64 inch is increased byturni ng upp e rlooperholder counter-
clockwise lookin g from leftendofmachine. Dimension 9/6~ inch is incr ea se d
by pulling upper looper holder left, out of the upper looper s haft. A ma ximum
dimension of 1/32 inch (Fig. 10) should be maintained betwe en the upper looper
holder and the upper looper shaft. After thes e chan g es are made, it may be
necessary to turn the upper looper around its shank sli g htly to maintain the
condition shown in Fig. 9.
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SETTING THE UPPEH LOOPER (Continued)
When the correct settinrr is obtained, it can be checked
quickly as follows: As upper looper is moving to the right,
when upper looper eye centers on the needle, the eyes of
the upper loop er and needle should align exactly (Fig. 11).
Check settin g to avoid interference between upper looper
and needle on n ee dle downstroke. If needle rubs the back
of upper loop e r, pull looper out of its holder slightly and
rotate looper a short distance counter- clockwise, lookin g
from left end of machine. Reset to maintain dimensions
of Fig. 9, J0, 11.
Fig. 11
SETTING THE FEED DOGS
Assemble the main and
differeniial feed dogs (A, B,
Fig. 12). Main and different i al
feed dogs should be leveled
with respect to the throat plate
by rotating feed tilting adjust-
ing pin (C). This pin raises or
lowers the back end of the feed
bar.
The feed dogs should be set
level at the time the teeth first
appear above the throat plate.
Fig. 12
Screw (D) locks feed tilting
adjusting pin in place. With the
f eed dogs at th e ir highest point of travel, the top of the teeth on the main and
differential feed do gs (A, B) should be 3/64 inch above the throat plate. The
c haining feed do g is made as on integral part of the main feed dog.
SETTING THE LOWER KNIFE
Replace lower knife holder assembly. Lower
knife (A, Fig. 13) should be set with cutting edge
flush with throat plate surface. Adjustments are
made with hexagonal head screw which holds lower
knife. Lower knife is spring pressed against upper
knife, so no lateral adjustment is necessary when
width of trim is changed.
Lower knife may be secured in any position by
ti g htening screw (B) and locking nut (C) agains t sup-
port bracket. Because screw (B) also serves as
latch pin for the cloth plate latch spring, it should
always be locked with nut (C) even when screw is not
ti g htened against lower knife holder.
SETTING THE UPPER KNIFE
Replace upper knife assembly. Clamp upper
knife (D, Fig. 13) in position, setting nut (E) to hold
Fig. 13
clamp (F) in its most clockwise position against upper knife. Upper knife chain
g uard (J) should be positioned so that the guarding section is approximately 1I 64
inch behind the cutting edge and in contact with th e top surface of the upper knife.
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SETTING THE UPPER KNIFE (Continued)
At the bottom of its stroke, front cutting edge of upper knife should extend not less th an
1/64 inch below cutting edge of lower knife.
After upper knife has been set for proper width of trim, screw (G) must be tightened
to lock the upper knife holding block (H) in pla ce . This will simplify resetting when upper
knife is repl a ced.
SETTING THE STITCH LENGTH
Length of stitch is determined by the combination of feed
eccentrics used. Outer (left) eccentri c (A, Fig. 14) actuates
main (rear) feed dog; while the inner (right) e cc entri c (B) actuates
the different ia l (front) feed dog.
In assembling feed eccentrics, be sure hubs ar e facing each
other. Be c areful not to dam age shaft or key. Tighten nut (C)
secur e ly. Be sure wool yarn in oil tube (F) touches feed eccentric
connections.
To chan ge feed ecc en trics, remove nut (C) from end of shaft
(D). Turn handwheel in operating dire cti on until key slot in
eccentric is toward front. Using hooked eccentric extractor (E),
supplied with machine, reach behind eccentrics as shown and
withdraw eccentrics. It may be necessary to move handwheel
back and forth slightly during extraction.
Fig. 14
If eccentrics are unusually tight f itt ing , in
addition to removing nut (C, F ig . 15) from shaft
(D), it may be helpful to remove nut (G) and feed
driving connection (H). Then continue as originally
suggested.
SETTING THE PRESSER FOOT
Fig. 15
Assemble presser foot to presser arm. With
needle in high position, swin g presser ar m into
sewin g pos i tion and lock in plac e . If necessary,
presser foot can be reali gned with throat plate slots
by shiftin g foot lifter lever shaft.
Foot lifter lever arm (A, Fig. 16) and collar (B)
secure the shaft. Be sure presser arm does no t bind
and rise when presser foot release bushin g is unlock-
ed. To center presser foot and stitch ton g ue with
respect to throat plate needle hole, loosen presser
foot hinge screw.
Adjust lifter lever stop screw (C) so that press er
foot can be raised no higher than upper looper will
permit; then, lock nut (D). To find this maximum
safe position, turn the handwheel so point of upper
looper is directly over presser foot tongue. Raise
presser foot by depressing the presser foot treadle
and manually lower the toe of foot. Height adJustm e nt
is correct if presser foot tongue does not contact the
upper looper. There should be from 1I 16 to 1/8 inch
free motion of foot lifter lever before presser f oot
made with screw (E), locked with nut (F).
Fig. 16
be gi ns to r ise . Thi s ad just me nt is
Finally, re-assemble chip guard, fabric g uard, cloth plat e .
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