UnionSpecial 39500 Series Instruction sheet

F IN EST QUALITY
STYL E
39 SOO MG
CATALOG
No.
103MG
®
INDUSTRIAL
SEWING
LEWIS • COLUMBIA
MACHINES
CLASS 39500
HI -S TYLED HIGH SPEED
SINGLE NEEDLE TWO THREAD
PLAIN FEED S ERGING MACHINES
FOR PRECLOSED TROUSER CUFFS
· CHICAGO
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Catalog No. 103 MG
(Supplement to Catalog No. 103 FJ)
INSTRUCTIONS
FOR
ADJUSTING AND OPERATING
LIST OF PARTS
CLASS 39500
Style 39500 MG
First Edition
Copyright 19 7 2
by
Union Special Machine Co.
Rights Reserved in All Countr i es
MACHINE COMPANY
INDUSTRIAL SEWING MACHINES
CHICAGO
Printed in U.S.A.
2
February, 1972
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IDENTIFI C ATION OF MACHINES
Each Union Special machine is identified by a Style number on a name plate on
the machine. Style numb e rs are classified as standard and special. Standard Style
numbers have one or more le tters suffixed, but never contain the letter "Z".
Example: "Style 39500 MG". 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 MGZ".
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 MG, but not on Style 39500
F J 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. Re-
ference 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. Reference to directions, such as right, left, front, back, etc., are g iven
from the operator's position while seated at the machine. Operating direction of
handwheel is away from operator.
STYLE OF MACHINE
Hi-Styled High Speed Single Curved Blade Needle, One Looper, One Spreader, Two
Thread Serging Machine. Plain Feed, Trimming Mechanism with Spring Pre s sed
Lower Knife, Automatic Lubricating System.
39500 MG Light to medium duty machine for serg i ng around pants cuff before cuffs
are folded and similar operations on light, medium and heavy weight trouser
material. Seam specification 503- EFd-1; standard seam width 3/16 inch; stitch
range 4- 8 per inch; cam adjusted feed. Maximum recommended speed 7000
R. P.M.
OILING
CAUTION! Oil was drained from machine when sh i pped, so reservoir must be
filled before beginnin g 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 ind i cator should show between g auge
lines when machine is stationary.
Machine is automatically lubricated. No oi li ng is necessary, other than k ee ping
main reservoir filled. Check oil daily before the morning start; add oil as required.
The oil drain plug s crew is located at back of machine near bottom edge of base .
It is a ma g netic screw designed to accumulate possible foreign materials which may
have enter ed the crank case. It should be remov ed and cleaned per i odically.
3
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NEEDLES
Each Union Special needle has both type and size number. The type numb er
denotes the kind of shank, point, length , groove, finish and other details. The siz e
number, stamped on the needle shank, denotes largest diameter of blade, measur -
ed 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 MG 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, 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, 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 044".
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 NEEDLES
Release pressure on presser foot by turning presser foot release bushin g (AG,
Fig. 1) and swing presser arm (U) out of position. Turn handwheel in ope rating
direction until needle is at its lowest point of travel. Using hexagonal sock et 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 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 andre-lock presser foot release bushin g (AG).
THREAD STAND
After thread comes from cones on cone support (A, Fi g. 1), it is brought up
through back hole of thread eyelet (B), then down throu gh the front hole of thread
eyelet. Next it is t hreaded through the upper holes of tension thread guide (C) from
front to back and then through the lower holes from back to front. Threads then
continue between tension discs (J), through tension post slot (K) in tension post (G)
and on throu gh front thread guide (M).
4
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m Tension Nut ~
IJ Tension Sprin g Fe rrul e
II Tension Sprin g~
[!] Tension Post ( ~~ -SJ ~ ~
IIJ spring Shield .. .
DTension
Discs ·.··
(I Tension Post Slo ~ --
II Tension Disc Felt·-..
[i Tension Thr ead Guide
~ Front Thr ead Guide
·, 0
IIJ Upper Looper Thread Eyelet
(il Auxiliary Looper Thread Eyelet
m Presser Arm
Fig. 1
-Needle Thread
Pull-off
5
~----- B Cone Support
Upper Looper
Thread Tube Assembly
Upper Looper
a Lower Spreader
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THREADING
Only parts involved in threading are shown in threading diagram (Fig. 1). Parts
are placed in their relative positions for clarity.
It will simplify threading this machine to follow recommended sequence of
threading the upper looper first and the needle second.
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 the threads, as they come from the tension thread guide (C), are between
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.
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 and push tube down; then insert thread
through upper looper eye from front to back.
TO THREAD THE NEEDLE
Turn handwheel in operating direction until needle (X, Fi g. 1) is at its hi g hest
position. Insert needle thread from right to left, through both eyes 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 needle and looper thread is re g ulated by two knurled
tension nuts (D, Fig. 1). Tension on threads should be only enough to secure proper
stitch formation.
PRESSER FOOT PRESSURE
Sufficient presser foot 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 adjusting screw (B). Adjusting screw
has a right hand thread so tighten i ng increases pressure,
loosening decreases pressure. When pressure adjusting s crew
(B) has been properly set, tighten lock nut (A). With presser
foot resting on throat plate, position locking nut (C) so that
itsunder surface isapproximately1/32 inch to1/16 inchfrom
the top surface of adjusting screw (B). Set cap (D) aga inst
locking nut (C).
6
Fig. 2
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FEED ECCENTRICS
The feed eccentric used in this machine has been selected to produce approxi -
mately 6 stitches per inch. It will be noted that the part number of the feed eccentric
is No. 39540 B- 6. Minor number of the part symbol indicates approximately the
number of stitches produced when using that eccentric. Unless otherwise specified,
machine will be shipped with the eccentric to produce the number of stitches as
outlined above.
The 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".
ASSEMBLING AND ADJUSTING SEWING PARTS
Before assembling and adjusting sewing parts, remove cloth plate, fabric
guard, chip guard, upper knife assembly and lower knife holder assembly; then
follow this suggested sequence.
Fig. 3
(B). With spreader at the left end of it s stroke,
center l~ne of needle (C). Looper gauge No.
21225-3/32 can be used advantageously in mak-
ing this adjustment. Do not have spreader
deflecting needle. Tighten nut (D).
Now assemble the feed dog (D, Fi g. 3)
SETTING THE REAR NEEDLE GUARD
Set rear needle g uard (A, Fig. 5) as hi gh
as possible, without int e rferin g with e ither th e
spreader or movement of low er knife hold e r,
but still in position to deflect needl e forw a rd
. 002 -. 004 inch . Scr ew (B) is us ed to se t rear
needle guard. Mak e su re ther e is no interf e r-
ence between rear n ee dle g uard and s pr ea der .
7
SETTING THE NEEDLE
With the 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 15/32 inch above
the throat plate (A, Fig. 3).
To align the needle or set the
height above the throat plate,
move needle driving arm (B) by
loosening clamp screw (C).
After needle has been properly
set, tighten clamp screw and
remove throat plate.
At this point, insert
spreader (A, Fig . . 4) into bar
set spreader point 3/32 inch from
Fig. 4
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SETTING THE SPREADER
Now complete the spreader adjustment. As spreader moves
to the right, its point should be set into the needle scarf (A, Fig.
6) until the needle springs forward from rear needle guard surface
another . 002 - . 004 inch.
SETTING THE FRONT NEEDLE GUARD
Assemble front needle guard (C, Fig. 5). When spreader 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 guards and feed dog.
SETTING THE UPPER LOOPER
Fig. 5
Insert upper looper (A, Fig. 7) in its holder. Screw (B) holds looper in its holder.
and permits it to be pushed in or out or turned around its shank. Insert looper holder
into looper shaft, if it is not already in place. Screw (C) on clamp collar holds looper
holder in the shaft, and allows holder to be
rotated or adjusted laterally.
Preliminary Setting: When looper is at
the right end of its stroke, looper holder
should be set to position upper looper shank
sli g htly back of vertical (Fig. 7). Top end of
l ooper shank should extend 1/32 to 1/16 inch
above the looper holder (Fig. 7).
As upper looper moves from right to
left the looper should pass behind the lower
spreader, with approximately • 002 inch
clearance between spreader and upper
looper (Fig. 8). When the looper is at its Fig.
7
Fig. 6 extreme left end of travel, its point should
extend 5/32 inch to the left of the centerline of the needle and
should be 15/32 inch above the top of the throat plate (Fig. 9). If resetting is nec-
essary, reposition the upper looper holder (A, Fig. 8).
The 5/32 inch dimension
can be increased by pulling the
upper looper holder to the left ,
Ol;lt of the looper shaft. The
15/ 32 inch dimension can be
increasedbyturningthelooper
holder in a counterclockwise
direction, looking from the
left end of the machine. After
these changes are made, it
may be necessary to turn the
looper around its shank slight-
ly to maintain the condition
Fig. 8 shown in (Fig. 8).
Now check setting between looper and needle. If
needle rubs the back of looper, pull looper out of its
Fig. 9
holder slightly and rotate looper a short distance counterclockwise
left end of machine. Reset to maintain dimensions of (Figs. 8 and 9).
8
looking from
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SETTING THE FEED DOG
The feed dog (A, Fig. 10) should be leveled with respect to the throat plate by
rotating the feed tilting adjusting pin (B). This pin raises or lowers the back end of
the feed bar (C). The feed dog should be set level at the time its teeth first appear
above the throat plate. Screw (D) locks the feed tilting adjusting pin in place.
Fig. 10
The tips of the feed dog teeth should extend the depth of a tooth or approximately
3/64 inch above the throat plate at high point of travel. The elongated slot in the feed
dog for its attaching screw (E) has been provided for this purpose.
SETTING THE LOWER KNIFE
Replace lower knife holder assembly.
Lowerknife (A, Fig. 11) shouldbe setwith
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 tightening screw (B) and locking
nut (C) against support bracket.
SETTING THE UPPER KNIFE
Replace upper knife assembly. Clamp
upper knife {D, Fig. 11) in position, setting
nut (E) to hold clamp (F) in its most clock-
wise position against upper knife. At
bottom of its stroke, front cutting edge of Fig. 11
upper knife should extend not less than
1764 inch below cutting edge of lower knife. The chain guard (G) should be set down
against the upper knife and slightly back from the cutting edge.
After upper knife has been set for proper width of trim. screw (H) should be
tightened to lock upper knife holding block (J) in place. This will simplify resetting
when upper knife is replaced.
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SETTING THE STITCH LENGTH
Length of stitch is determined by the feed eccentric used in machine. Note that
the part _ number of the feed eccentric for Style 39500 MG is No. 39540 B-6.
In assemb li ng the feed eccentric (A, Fig.
12), 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.
Tighten nut (C) securely.
To change feed eccentric, remove nut (C),
washer (D) and feed eccentric spacer (B). Turn
handwheel in operating direction until key slot
in eccentric is toward the front. Using hooked
eccentric extractor No. 21227 BF, supplied with Fig. 12
machine, reach behind eccentric 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 holes (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 important 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 .
13). To move the shaft, loosen collar screws (B) 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.
The foot lifter
lever arm (A) 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 per-
Fig. 13 mit; then lock the nut
(D). There should be
from 1/16 to 1/8 inchfree motion of foot lifter lever before
the presser foot be g ins to rise. This adjustment should be Fig. 14
made with screw (E) and locked with nut (F). Re-assemble
the chip guard, fabric guard and cloth plate. To assemble chip guard, turn h an dwheel
until upper knife assembly reaches its highest position.
CLOTH PLATE REMOVAL AND ASSEMBLY
CAUTION: When removing the cloth plate (A, Fig. 14) loosen the cloth plate stud
locking screw (B) and lift up cloth plate with the cloth plate stud (C) and cloth plate
screw (D), assembled.
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