UnionSpecial 63900 Series Guide

ADJUSTING INSTRUCTIONS / ILLUSTRATED PARTS LIST
MANUAL NO. PT9636
STYLES
63900STREAMLINED
HIGHSPEEDNEEDLEFEED
TOPAND BOTTOMROLLERFEED
LOCKSTITCHMACHINES
63900AM
63900AML
63900AT
63900AW
63900AAE
REV.08/31/98

CONTENTS
•PREFACE............................................................................................................................................................... 4
•SAFETYRULES ........................................................................................................................................................ 5
•IDENTIFICATIONOFMACHINES........................................................................................................................... 6
•CLASS DESCRIPTION ........................................................................................................................................... 6
•STYLEOFMACHINES ............................................................................................................................................ 6
•ILLUSTRATIONS ...................................................................................................................................................... 6
•ILLUSTRATIONS(CONT.) ....................................................................................................................................... 7
•IDENTIFYINGPARTS .............................................................................................................................................. 7
•NEEDLES ................................................................................................................................................................ 7
•TABLEBOARD........................................................................................................................................................ 8
•BOBBINWINDER................................................................................................................................................... 8
•BELTS ..................................................................................................................................................................... 8
•LUBRICATION........................................................................................................................................................ 9
•RECOMMENDED OIL ........................................................................................................................................... 9
•OIL GAUGE .......................................................................................................................................................... 9
•SELF-PRIMINGHEADOILSIPHON ...................................................................................................................... 10
•INSTALLINGANDMAINTENANCEOFOILSIPHON............................................................................................ 10
•THREAD............................................................................................................................................................... 11
•REMOVINGTHEBOBBINCASE .......................................................................................................................... 11
•WINDINGTHEBOBBIN ....................................................................................................................................... 11
•THREADINGTHEBOBBINCASE.......................................................................................................................... 11
•THREADINGTHEBOBBINCASE(CONT.) ........................................................................................................... 12
•REPLACINGTHEBOBBINCASE.......................................................................................................................... 12
•INSERTINGTHENEEDLE ...................................................................................................................................... 12
•THREADINGTHENEEDLE .................................................................................................................................... 12
•PREPARATIONFORSEWING .............................................................................................................................. 12
•TENSIONS ............................................................................................................................................................ 12
•BOBBINTHREADTENSION .................................................................................................................................. 12
•BOBBINTHREADTENSION(CONT.) ................................................................................................................... 13
•NEEDLETHREADTENSION .................................................................................................................................. 13
•CHANGINGTHESTITCHLENGTH ....................................................................................................................... 13
•TIMINGTHENEEDLEFEEDWITHTHECONTINUOUSTURNINGROLLERFEED.................................................... 14
•PRESSUREONMATERIAL .................................................................................................................................... 14
•SETTINGTHENEEDLEBARTOHEIGHT ................................................................................................................ 14

CONTENTS(CONT.)
•TIMINGTHEHOOK ............................................................................................................................................. 15
•NEEDLEGUARDINSTRUCTIONS ......................................................................................................................... 15
•NEEDLEGUARDINSTRUCTIONS(CONT.) .......................................................................................................... 16
•HOOKLUBRICATION.......................................................................................................................................... 16
•PRESSERBARGUIDE ........................................................................................................................................... 16
•PRESERBARCONNECTION ............................................................................................................................... 16
•TENSIONASSEMBLYADJUSTMENT ..................................................................................................................... 17
•TENSIONRELEASE ............................................................................................................................................... 17
•THREADCONTROL............................................................................................................................................. 17
•THREADCONTROL(CONT.) .............................................................................................................................. 18
•BOTTOM COVER ................................................................................................................................................ 18
•HOOKSHAFT ...................................................................................................................................................... 18
•HOOK SHAFT (CONT.)........................................................................................................................................ 19
•REMOVAL OF OILING DEVICE .......................................................................................................................... 19
•REASSEMBLYOFOILINGDEVICE ...................................................................................................................... 20
•REASSEMBLYOFOILINGDEVICE(CONT.)........................................................................................................ 21
•UPPERMAINSHAFT ............................................................................................................................................ 21
•UPPERMAINSHAFT(CONT.) ............................................................................................................................. 22
•HANDWHEEL ...................................................................................................................................................... 22
•HANDWHEEL (CONT.)........................................................................................................................................ 23
•ATTACHMENTS ................................................................................................................................................... 23
•NEEDLEHOLEINSERT .......................................................................................................................................... 23
•MAINFRAME,BUSHING,OILGAUGEHEADOILSIPHONANDMISCELLANEOUSOILINGPARTS.................... 25
•MAINFRAME,BUSHING,OILGAUGEHEADOILSIPHONANDMISCELLANEOUSOILINGPARTS(CONT.) ..... 27
•MAINFRAMEMISCELLANEOUSCOVERSANDNEEDLETENSIONPARTS ......................................................... 29
•MAINFRAMEMISCELLANEOUSCOVERSANDNEEDLETENSIONPARTS(CONT.) .......................................... 31
•MAINANDHOOKDRIVESHAFTS,NEEDLEBARANDFOOTLIFTERMECHANISM............................................ 33
•NEEDLEFEEDDRIVINGPARTS............................................................................................................................ 35
•PRESSERFEET,PRESSERBAR,TOPFEEDROLLERMECHANISMANDATTACHMENTS ....................................... 37
•PRESSERFEET,PRESSERBAR,TOPFEEDROLLERMECHANISMANDATTACHMENTS ....................................... 39
•ROTATINGHOOKASSEMBLYANDHOOKOILINGPARTS ................................................................................ 41
•FEEDROLLERDRIVINGPARTS............................................................................................................................ 43
•FEEDROLLERDRIVINGPARTS(CONT.) ............................................................................................................. 45
•BOBBINWINDERANDMISCELLANEOUSACCESSORIES .................................................................................. 47
•NUMERICALINDEXOFPARTS ............................................................................................................................ 48
•NUMERICALINDEXOFPARTS ............................................................................................................................ 49
•NOTES ................................................................................................................................................................. 50
•NOTES ................................................................................................................................................................. 51

4
First Edition Copyright 1997
By
Union Special Corporation Rights Reserved In All Countries
Printed in U.S.A. October 1997
Manual No. PT9636 Illustrated Parts List for 63900 Series Machines
PREFACE
This parts manual has been prepared to assist you in locating individual parts or assemblies on 63900 Series
machines.
It is the desire of Union Special that each machine run at its optimum performance. Parts listed in this manual
are designed specifically for your machine and are manufactured with utmost precision to assure long
lasting service.
This manual has been comprised on the basis of available information. Changes in design and/or
improvements may incorporate a slight modification of configuration in illustrations or part numbers.
On the following pages are illustrations and terminology used in describing the parts used on 63900 Series
machines.

5
SAFETYRULES
1. Before putting the machines described in this manual into service, carefully read the instructions. The
starting of each machine is only permitted after taking notice of the instructions and by qualified
operators.
IMPORTANT! Before putting the machine into service, also read the safety rules and instructions from the
motor supplier.
2. Observe the national safety rules valid for your country.
3. The sewing machines described in this instruction manual are prohibited from being put into service until
it has been ascertained that the sewing units which these sewing machines will be built into, have
conformed with the EC Council Directives (89/392/EEC, Annex II B).
Each machine is only allowed to be used as foreseen. The foreseen use of the particular machine is
described in paragraph “STYLES OF MACHINES” of this instruction manual. Another use, going beyond
the description, is not as foreseen.
4. All safety devices must be in position when the machine is ready for work or in operation. Operation of
the machine without the appertaining safety devices is prohibited.
5. Wear safety glasses.
6. In case of machine conversions and changes all valid safety rules must be considered. Conversions and
changes are made at your own risk.
7. The warning hints in the instructions are marked with one of these two symbols:
8. When doing the following the machine has to be disconnected from the power supply by turning off the
main switch or by pulling out the main plug:
8.1 When threading needle(s), looper, spreader etc.
8.2 When replacing any parts such as needle(s), presser foot, throat plate, looper, spreader, feed
dog, needle guard, folder, fabric guide etc.
8.3 When leaving the workplace and when the workplace is unattended.
8.4 When doing maintenance work.
8.5 When using clutch motors without actuation lock, wait until the motor is stopped totally.
9. Maintenance, repair and conversion work (see item 8) must be done only by trained technicians or
special skilled personnel under consideration of the instructions.
10. Any work on the electrical equipment must be done by an electrician or under direction and supervision
of special skilled personnel.
11. Work on parts and equipment under electrical power is not permitted. Permissible exceptions are
described in the applicable sections of standard sheet DIN VDE 0105.
12. Before doing maintenance and repair work on the pneumatic equipment, the machine has to be
disconnected from the compressed air supply. In case of existing residual air pressure, after disconnect-
ing from compressed air supply (i.e. pneumatic equipment with air tank), the pressure has to be
removed by bleeding.

IDENTIFICATIONOFMACHINES
Each UNION SPECIAL machine is identified by a style number, which is stamped into the style plate affixed
to the middle of the machine under the tension assembly. The serial number is stamped into the serial
number plate affixed to the right rear base of the machine.
CLASS DESCRIPTION
High speed streamlined long arm needle feed lockstitch machines. one needle, light, medium and heavy
duty, continuous running roller feed, rotary hook, horizontal hook shaft, gears for changing stitch length, slot
segment for adjusting needle feed, 1 1/4 inch needle bar travel, one reservoir enclosed automatic
lubrication system, head oil siphon, adjustable hook oil control, needle bearing for take-up lever and needle
bar driving link, needle feed timing on upper shaft, maximum work space to right of needle bar 8 inches.
STYLEOFMACHINES
63900AM For making 3/8 on 1/2 inch turned down hem on legs of overalls, coveralls, and dungarees.
Seam Specification 301-EFb-1 inverted, Specify size of hem. Maximum recommended speed
5200 R.P.M.
63900AML Same as 63900AM except includes a hook with 52% greater bobbin capacity to reduce
frequency of bobbin changes.
63900AT For making a 1/2 or 2 1/2 inch hem turned by hand on children's wear, men's dress pants,
semi-dress pants and work pants. Sewn when garment reaches machine inside out. Seam
Specification 301EFb-1 or EFa-1. Maximum recommended speed 5200 R.P.M.
63900AW For top stitching waistbands on twill and woolen pants. Machine equipped to sew over belt
loops. Fitted with cloth plate extension. Seam Specification 301-SSa-1. Maximum recom-
mended speed 5200 R.P.M.
63900AAE Same as Style 63900AW, except fitted with spring guide keel on presser foot in line with
centerline of needle hole.
ILLUSTRATIONS
This manual has been arranged to simplify ordering repair parts. Exploded views of various sections of the
mechanism are shown so that the parts may be seen in their actual position in the machine. 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 in the particular view being shown.
Numbers in the first column are reference numbers only, and merely indicate the position of the part in the
illustration. The reference number should never be used in ordering parts. Always use the part number listed
in the second column.
Component parts of sub-assemblies which can be furnished for repairs are indicated by indenting their
descriptions under the description of the main sub-assembly. As an example refer to the following text.
18. 29126EL Needle Feed Driving Eccentric and Connecting Rod Assembly ................................. 1
19. 22894J Set Screw .................................................................................................................. 2
6

7
ILLUSTRATIONS(CONT.)
When a part is common to all machines covered in this manual, no specific usage will be mentioned in the
description. However, when the parts for the various machines are not the same, the specific usage will be
mentioned in the description and, if necessary, the difference will be shown in the illustration.
*Ref. No. showing no Part No. is for location only. Part is not for sale separately.
A numerical index of all the parts shown in this manual is located at the back. This will facilitate locating the
illustration and description when only a part number is known.
IDENTIFYINGPARTS
Where construction permits, each part is stamped with its part number. On some of the smaller parts and on
those where construction does not permit, an identification letter is stamped in to distinguish the part from
similar ones.
PLEASE NOTE: Part numbers represent the same part, regardless of which manual they appear. On all
orders please include part number, name and style of machine for which the part was ordered.
For optimum performance use only genuine Union Special replacement parts.
NEEDLES
Each needle has both a 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 the largest
diameter of the blade measured between the shank and the eye. Collectively, the type number and size
number represent the complete symbol which is given on the label of all needles packed and sold by Union
Special.
TYPE DESCRIPTION
180GYS Round shank, round point, lockstitch, short length ball eye single groove, struck groove, deep
spot, chromium plated - sizes 075/029, 080/032, 090/036, 100/040, 125/049, 140, 054, 150/060.
180 GWS Round shank, round point, lockstitch, short length, oversize ball eye, single groove, struck
groove, deep spot, chromium plated - sizes 090/036, 100/040, 110/044, 125/049, 140/054.
When changing the needle, make sure it is fully inserted in the needle holder before the screw is tightened.
When ordering needles, please use the complete type and size numbers as printed on the package to
ensure prompt and accurate processing of your order. A complete order should read as follows: "100
needles, type 130 GS, size 125/049".

8
TABLEBOARD
The tableboard can now be mounted on the pedestal using four screws, adjusting the nuts so the top of the
tableboard is flush with the top of the machine bed plate.
BOBBINWINDER
The bobbin winder should be secured to the table top so that its pulley will be located directly in front of the
sewing machine belt and will bear against the belt when in operation. The base of the winder has two
elongated attaching holes, which allow the mechanism to be moved closer to or farther away from the belt
as needed. The pulley of the winder, when in operation, should exert only enough pressure against the belt
to wind the bobbin. Regulation and operation of the bobbin winder is described under "Winding The
Bobbin", under "Instructions For Operator's".
BELTS
These machines are equipped to use either #1 "Vee" or round belts.
Fig. 3

9
LUBRICATION
CAUTION! Oil has been drained from the main reservoir before shipment and the reservoir must be filled
before starting to operate.
Lubricate machine thoroughly, in accordance with instructions which follow, and run slowly for several
minutes to distribute the oil to the various parts. Full speed operation can then be expected without
damage.
RECOMMENDEDOIL
Use a stainless water-white straight mineral oil of a Saybolt viscosity of 90 to 125 seconds at 100° Fahrenheit
in the main reservoir. This is equivalent to Union special specification No. 175. Fill main reservoir at plug
screw (B, Fig. 3) and check oil level at gauge (C): oil is at maximum level when needle is in yellow band
marked "FULL". Oil should be added when needle is in yellow band marked "LOW".
It is recommended that a new machine, or one that has been out of service for an extended period, be
lubricated as follows: Remove the head cover and directly oil the bearings of the needle bar link, the take-
up and its lever and needle bar. Replace end cover, as no further hand oiling will be required.
Oil may be drained from main reservoir by removing plug screw (D, Fig. 3).
OIL GAUGE
The oil gauge is set at the factory to show the proper oil level in the reservoir. Should and adjustment
become necessary, the following steps should be followed:
1. Place the machine upright on a level table or bench.
2. Remove the reservoir plug screw (located below the handwheel and near the bottom of the
machine).
3. Oil should be added or removed so that the oil level is approximately 1/8 inch below the bottom edge
of the hole.
4. Loosen lock nut (E, Fig. 3) on the calibrating screw (F), and turn screw left or right so the gauge needle
rests on the yellow band marked "FULL" on gauge (C).
5. Tighten lock nut and replace plug screw.

10
10
SELF-PRIMINGHEADOILSIPHON
Class 63900 machines are equipped with a self-priming head oil siphon. When the machine is started, oil
splashes on the priming cup felt, filters through the felt and trickles down the vertical oil tube, thus priming
the siphon. Once the prime is established, it is maintained, unless the felt is removed. The siphon operates
twenty-four hours a day, removing oil at the rate of six to twelve drops per minute, which, of course, far
exceeds the rate at which oil collects in the head.
INSTALLINGANDMAINTENANCEOFOILSIPHON
A newly installed siphon starts its action within three to five minutes after the machine is operating. However,
it may be twenty minutes or so before all the air is removed from the line and the siphon is in full operation.
Within an hour, there should be a distinct reduction of the oil in the head sump. If the siphon does not
function, determine if the siphon intake tube, located in the head, is inserted in the felt block and that the
plastic tube is connected at both ends. If the above two items do not correct the siphon, replace the siphon
felts as described below.
The felt in the priming cup is designed for a specific purpose. This felt, No. 666-237, is to meter the flow of
priming oil and to prevent the entrance of air. The felt also acts as a filter and keeps the siphon clear of lint.
If the priming cup felt and the intake felt (666-214) becomes contaminated with an excessive amount of lint,
it may be necessary to replace the felts. The priming cup felt is replaced by removing access plug at back
of machine and replacing felt 666-237. For the best initial self-priming condition, the felt of the siphon should
be installed dry. The intake felt is replaced by removing the end cover.
However, if for some reason the priming cup felt has been oiled before installing, the siphon may fail
because air is trapped in the felt. As a precaution, remove felt from cup. Then, while squeezing the felt
between the fingers, saturate it well with oil. In other words, squeeze out the air and replace it with oil. This
prevents the trapping of air, and no trouble should be experienced when starting the siphon.