Global 3995DD Series Product guide

INSTRUCTION MANUAL BOOK & PARTS BOOK
3995DD/3995AUT Ser is
GLOBALSEW.COM
DIRECT DRIVE TOP AND BOTTOM FEEN
LOCKSTTICH SEWING MACHINE WITH
AUTOMATIC THREAD TRIMMER

CONTENTS
Operation instruction
1.Brief introduction ........................................................................................... 1
2.Machine specification
...................................................................................... 1
3.Installing
the oil pan ................................................................. ······················ 1
4.Installing
the machine head ............................................................................ 2
5.Installing the knee lifter assy ........................................................................... 2
6.Adjusting the knee lifter .................................................................................. 3
7.Lubrication .................................................................................................... 3
8.Test operation
............................................................................................... 4
9.Installing
the needle ....................................................................................... 5
10.Removing the bobbin case ............................................................................. 5
11.Winding
the bobbin thread ............................................................................ 5
12.Threading
the bobbin thread .......................................................................... 6
13.Threading
the needle thread .......................................................................... 6
14.Adjusting
the stitch length ............................................................................. 7
15.Sewing and backtacking ................................................................................ 7
16.Adjusting the thread tension .......................................................................... 8
17.Adjusting the presser foot pressure ................................................................ 8
18.Adjusting
the trailing length after thread trimming ........................................... 9
19.Adjusting
the thread tension spring ................................................................ 9
20.Adjusting
the upper thread guide .................................................................. 10
21.Adjusting
the presser foot height .................................................................. 10
22.Adjusting
the feed dog height ...................................................................... 10
23.Adjusting the feed dog angle ....................................................................... 11
24.Adjusting the difference of stitch length between the forward and backtacking ............ 11
25.Adjusting the tension release ....................................................................... 11
26.Adjusting the timing of needle and feed mechanism ........................................ 12
27.Adjusting
the rotary hook lubrication amount ................................................. 12
28.Adjusting
the height of needle of needle bar and the timing with hook .................. 13
29.Adjusting the oil pump ................................................................................ 13
30.Adjusting the lifting amount of presser feet .................................................... 14
31.Adjusting the trimming mechanism .......................................................... 15-16
32.Clean ........................................................................................................ 17
Parts Manual
1.Casting mechanism .................................................................................. 18-19
2.Needle bar and thread take-up mechanism .................................................. 20-21
3.Presser foot mechanism ............................................................................ 22-23
4.Feed mechanism
...................................................................................... 24-27
5.Upper feed mechanism
............................................................................. 28-29
6.Hook mechanism ..................................................................................... 30-31
7.Lubrication mechanism
.............................................................................. 32-33
8.Thtead trimming mechanism ...................................................................... 34-35
9.Reverse stitching mechanism ..................................................................... 36-37
10.Accessories for model ............................................................................. 38-39
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

Operation Instruction
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

1. Brief introdution
This machine is designed with link type
feed mechanism snd link leverthread take-up
mechanism and full lubrication by pump.It's
suitable for sewing leather ,canvas and other
heavy weight materials,such as suitcase,car
seat, tent,sofa, etc.
It's reliable and accurate on such functions
as
thread trimming,needle positioning,etc.
2. Main specifications
Model 399SDD
l399SAUTl399SCXAur
Applications
Medium&heavy weight materials
Max saving speed 2000 s.p.m
~ 800s.p.m
Max stitch length
8mm
112mm
Needle bar stroo
37mm
Ufting amount
3.5-5.Smm
of presser feet
Needle DPx17
23#
IDPx17 25#
Presser footl Bvhm::J
18mm
lifting height IBylqiee
16mm
Hook
Large lubrication hook
Lubrication
Automatic lubrication
Motor power
750W
3. Installing the oil pan(Fig.1)
1.Insert the two head cushion (2) into the
front corners of the oil pan CD;
2.Insert the two head cushion @ into the
back corners of the oil pan CD;
3.Place the oil pan@ into the cutouts of table;
4.Insert the two rubber cushion @ into
the notches of table.
5.Insers the safety switch magnet @ into
the hole of the table near oil pan cutout.
-1-
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

-2-
14. Installing the machine head(Fig.2)
1. Insert the knee lifter lifting bar CD.
2. Insert the two hinges ® into the holes in
the machine bed.
3.Clamp the two hinges onto the rubber
cushions ® in the work table,and the place
the machine head onto the head cushions @
which are on the top of the oil pan comers.
4.Tap the rest bar @ into the table hole.
NOTE:Tap the rest bar securely into the
table hole
,if not ,the machine head will
not be safe when
it is tilted back.
5. Installing the knee lifter assy.(Fig. 3)
Insert the knee lifter assy.(D into the shaft®
under the oil pan,and slightiy tight the screw ®·
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

I 6. Adjusting knee lifter(Fig.4)
1.Lower the presser foot ® by turning the
presser foot bar lifter CD.
2. Loosen the nut @.
3.Turn the screw @ to adjust the bracker
@to
2mm play.
4.Securely
tighten the nut @.
5.Loosen the nut (J).
6.Turn the screw @ until the distance
between the
end of the screw and bracket
is
approxim ately 8mm.
7.Turn the adjusting screw @
to adjust, so
that the presser foot is at the desired position
within adistance of 16mm above the
needle
plate
when the knee lifter plate@ is fully pressed.
8.After adjustment,tighten the nut.
7. Lubrication(Fig. 5)
1.0il amount
Please fill the oil according tothe mark indicated
on the oil pan.Mark(A)means the highest
position.Mark(B)means the lowest position.if
the
oil amount is lower than the Mark (B),oil
will not be pumped and machine will be
jammed.
2.Fill the oil
Please fill the 18#sewing oil into the oil pan
until to the Mark(A)
3.Clean
the oil
1.Uninstall the screw(C),and drain outthe
used oil.
2. Clean the oil pan,and tighten the
screw(C),fill the fresh oil again
according the requirement.
-3-
0
8
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

-4-
I a. Test operation(Fig.6)
Carry out the test operation when start up
a new sewing machine for the first time,or
restart after a long period of non-use.
Remove the rubber cap (A) on the top of
the arm and face plate,fully lubricate the
parts showed by the arrows.
Install the face plate again,lift the presser
foot and operate the machine at a lower
speed of 1000-lS00spm,and observe the
oil running
through the oil gauge window.
After one month,then the speed can
be
increased according to the different sewing
operation.
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

19. Installing the needle(Fig.7)
1.Turn the machine pulley to move the
needle bar CD to it's highest position;
2.Loosen
the screw®.
3.Insert the needle ® in a straight line as
far as it will go,making sure that the long
groove on the needle is at the left,and
then securely tighten the screw®.
10 . Removing the bobbin case (Fig. 8)
1.Turn the machine pulley to lift the needle
bar
to its highest posistion,Pull the latch CD
of the bobbin case upward and then put the
bobbin into the bobbin case,finally insert
the complete bobbin case with bobbin into
the hook shaft.
2.To remove the bobbin case,pull the latch
and draw the bobbin case out of the hook.
11 . Winding the bobbin thread (Fig. 9)
1.Turn the power on;
2. Place the bobbin CD onto the bobbin
winder shaft
®;
3.Wind the thread several circles around the
bobbin in the direction indicated by arrow;
4.Push down the bobbin presser arm ® ;
5.Life the presser foot ;
6.Depress the treadle , the winding
operation will start;
7.0nce finished, the bobbin presser
arm ® will release automatically.
*If the thread winding is not neat and
even,loosen the screw@
to adjust the
position of bobbin presser arm ®
*Turn the screw@ to adjust the bobbin
winding amount
Note:
The proper winding amount shoule be
around 80% of the bobbin capacity.
-5-
X 0
1~11~1
Long groove in needle~
;:-BO%
fmlJ Standard thread
~ winding amount
hlJI~
X O X
¢ Front
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

0
112. Threading the bobbin thread(Fig.1 o)I
1.Turn the machine pulley to life the needle
its highest position.
2.The bobbin thread should
be right twist,
place the bobbin into the bobbin case;
3.Pass the thread through the slot
CD and
spring plate ®,
and finally pull it out ofthe
notch®;
4.Check thatthe bobbin should tum clockwise
if the thread is pulled;
5.Hold the latch
@, and p I ace the bobbin
case in the hook.
I 13. Threading the needle thread(Fig.11)I
Raise the thread take-up lever to its highest posistion.This will make threading easier and will
prevent the thread from coming out at the sewing start.
-
Threading as below if
the resistance of thread
is large
hhread trails
- 5-0m_m_
1
-6-
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

I 14. Adjusting the stitch length(Fig.12)I
While press the stopper ®,turn the stitch
length dial CD to make the number on the
dial align with the mark on the stopper ®·
The number is the stitch length in mm.
*The larger the number ,the longer the stitch
length will be.
*when turn the dial from a larger setting
to a
smaller setting,it will be easy
to turn if the
reverse lever® is pressed down.
11 s.Sewing and backtacking(Fig.13)
1.Turn the power on;
2.Depress
the treadle to start sewing.
When
the reverse lever CD is pressed or
the backtacking button is on during
sewing,
the feed will be reversed.After release,the
feed will recover
to normal.
-7-
~
~
@
/~
I I
I o
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

I 16. Adjusting the thread tension(Fig.14)
Normal seam
~ - ◄◄ -_Needle thread
- - Bobbin thread
-•Stitch seam_wh~n needle
thread tension
1s weak
►
• ncrease the needle thread tension
• decrease the bobbin thread tension
eStitch seam when needle
thread tension
is too strong •
decrease the needle thread tension
• increase the boobin thread tensior
Increase
creas r.
(J)} Decrease
Increase
......_~.,._,._ ....
<Bobbin thread tension>
Adjust by turning the screw CD until the bobbin case
drops gently by its own weight while the thread end
coming out
of the bobbin case is held
<Needle thread tension>
After adjust the bobbin thread tension,adjust the
needle thread tension so that a good,even stitch
seam is obtained.
1.Lowerthe presser foot;
2.Adjust by turing the thread tension
nut®.
-8-
7. Adjusting the presser foot pressure (Fig .1 5)
<Adjusting the presser foot pressure>
1.Loosen the lock nut CD ;
2.Turn the adjusting screw ® to adjust the
pressure of presser foot,if it's not enough,
please tum the screw @ to increase the
pressure.
*The pressure should
be as week as
possible,but strong enough so that the
material doesn't slip.
3.Tighten the
nut CD.
<Adjusting the walking foot presser>
1.Loosen the nut @ ;
2.Turn the screw @ clockwise to increase
the pressure,on the contrary,turn the
screw counterclockwise
to decrease the
pressure;
3.Tighten the nut@.
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

r 8. Actusting thetiailing IEnQlh aftET1hwdmimrg(Fg . 16) I
Turn the nut CD to adjust the trailing length
*At the time of thread trimming,the thread
tension mechianism will release and
the
needle guide CD;
*The standard trailing length for the needle
thread is 40-70mm;
*If increase the thread guide tension,the
trailing length will
be short;if decrease the
thread guide tension,the trailing length will
be longer.
19 . Adjusting the thread tension spring(Fig.17)
*The standard position of the thread
tension spring
CD is 5-Smm above the
upper surface of the thread guide ®
when the presser foot® is lowered.
1.Lower
the presser foot ® ;
2.Loosen the screw @;
3.Turn
the thread tension bracket @ to
adjust the spring position;
4.Tighten
the screw@.
*The standard tension of the spring is
0.3-0.6N.
5. Push the needle thread with your finger
until it is slightly higher than the thread
tension
bracket@ and so that the upper
thread is not pulled out;
6. Pull the needle thread down until the
spring CD is at the same height with the
upper surface of thread guide @,and then
measure thye tension of the spring.
7.Insert a screwdriver into the slot of the
thread tension stud @,and turn the stud to
adjust the tension of the spring CD.
Noto:
If using a tension gauge (!) to measure
the tension,take the reading from the
scale on the side of the red line.
0.3 -0.6N
-9-
1---1
40~70mm
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

,JrLe ~ Decrease
TI~: : :+
' ' '
0
8mm
-10-
20. Adjusting the upper thread guide(Fig.18)
The standard position of upper thread guide CD
is where the screw ® is in the center of the
adjustable range
of upper thread guide.
Toadjust the position,loosen the screw ® and
move the thread guide.
If stitch the heavy materials,move the thread
guide leftward.(To increase the thread
take-up tension)
If stitch the light materials, move the thread
guide rightward.(to decrease the thread
take-up tension)
21 . Adjusting the presser foot height.(Fig.19)
The standard height of predder foot CD is
8mm when it is lifted by hand.
1.Loosen the screw@ to lift the presser bar
2.Put a measurement gauge with
8mm
height under the presser foot;
3.Loosen the screw @ and adjust the height
of presser foot;
4.Tighten the screw@.
I 22 . Adjusting the feed dog height (Fig.20) I
1.Set the stitch length maximum,when the
feed dog
CD is at its highest position above
the needle plate,the standard height is 1.2mm
2.Loosen the
screw® and turn the feed
lifting arm @ to adjust the height
of feed dog.
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

I23. Adjusting the feed dog angle(Fig.21)
The standard angle of the feed dog is:when
the feed dog is at its highestion above the
needle plate,the Mark on the feed bracket
shaft is on the horizontal position.
1.Turn
the machine pulley to lift the feed
dog toits highest position;
2.Loosen
the screw (!) ;
3.Turn the feed bracket shaft in the
direction of the arrow within a range of 90
with respect to the standard angle position.
*In order to prevent puckering,lower the
front of the feed dog (Fig.A)
*In order to keep the materials straight,
raise
the front of the feed dog (Fig.B)
4.Securely
tighten the set screw (!).
It's necessary to adjust thefeed dog height
again after this adjustment.
24 . Adjusting the difference of stitch length between
the forward snd backtacking(Fig . 22)
1.Remove the rear cover;
2. Loosen the screw CD and turn the
connecting stud ®
*Turn the stud ® clockwise,the forward
stitch length will be longer and the
backtacking stitch length will be shorter;
*Turn the stud ® counterclockwise,the
forward stitch length will be shorter and
the backtacking stitch length will be longer;
3.Tighten
the screw CD .
I 2s. Adjusting the tension release(Fig.23)I
The opening time of the thread tension
discs can be adjusted.
Remove the rubber cap on the rear of arm,
and turn the screw
CD ,then the thread
release cam ® can be moved
left or right.
Move
the cam rightward,the release time
will be slow
Move
the cam leftward,the release time
will be quick.
-11-
0
0
11B + """""~ l!il!!rn Standard
,::--
@) + ~ ~ ~ Lower the front
__,, .
(Fig.A)
® ♦
(Fig.B)
,::-- !
~~~Raise the front
I
0
c:::::,
" I
~
L----,--~---
1 't:: 17,
" I
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

Needle timing advanced
Standard Needle timing retarded
Smaller Larger
f(I!)\
-12-
26. Adjusting the timing of needle and feed
mechanism(Fig.
24)
The standard timing is when the feed dog is
lowered from its highest position until its flush
with the top
of the needle plate ®,and the
needle eye ®
is also aligned horizontally with
the surface.Adjust by changing the phases
of
feed cam and eccentric wheel UD
1.Remove the rear cover
2.Turn the machine pulley in reverse direction,
set
the secong screw@on the gear of upper
shaft as reference mark,make the third
screw@ of eccentric wheel UD slightly
lower than the reference mark screw @;
3.Continue to turn the machine pulley,set
the second screw@ of eccentric wheel UD
as refernce mark,make the third screw (J)
of feed cam slightly higher than the
reference mark screw@.
4.If need a non-timing position,loosen the
three screw of eccentric wheel UD,adjust
the eccentric cam @ in the direction of
arrow (A) or (B)
To increase the tension of thread,turn the
eccentric cam @ to direction (A)
To avoid the needle bent,turn the eccentric
cam @ to direction (B)
5.After adjustment,tighten all of the screws.
I 21 . Adjusting the rotary hook lubrication amount {Fig.25)1
Tilt back the machine head,and tum the oil
adjustment screw CD to adjust the hook
oiling amount.
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

28. Adjusting the height of needle bar and
the timino with hook(Fio.26)
When the needle bar CD is at its lowest
position,the top reference line(A)
on the
needle bar shoule be alined with the bottom
edge
of the needle bar bush ®·
1.Turn the machine pulley to lowerthe needle
bar
to its lowest position;
2.Take out the rubber
cap ®;
3.Loosen the screw @,and move the needle
bar CD to proper position;
4.Tighten the screw @;
5.Close
the rubber cap ®·
Lift the needle bar CD from the lowest position,
when the second reference line (B)
on the
needle bar
is aligned with the bottom edge of
the needle bar
bush ®,the tip @ ofthe hook
should
be aimed at the center of needle@.
1.Turn the machine pulley
to raise the
needle bar
CD from its lowest position until
the reference line(B) is aligned with the
bottom edge of the needle bar bush ®
*When the needle bar moves up 2mm,the
clearance between
the upper pf needle
hole and the hooktip should
be 1.3-1.Smm
2.Loosen the screw (/),and make the hook
tip aimed
at the center of needle @,the
clearance between the hook tip and needle
shoule be
0.05mm.
3.Tighten the screw (!).
I 29. Adjusting the oil pump(Fig.27)
If the oil is not circled observed from the oil
gauge window
at a lower sewing speed,turn
the oil adjustment plate
CD to cover the oil
hole®.
-13-
i
/11-
@
OP 17
DP X 17 1.3-1.
Smm
i
2.0mm
0. 05mm
0.5 - 1.0mm
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

Needle plate
Downward
-14-
30. Adjusting the lifting amount of presser feet(Fig . 28)
1.Vertical movement of presser foot and
walking foot
*The walking foot
CD and presser foot®
move vertically one after another
*Usually the stroke
of walking foot and
presser foot is same or the stroke of presser
foot is slightly lower.
Place the thread take-up lever at the lowest
position,and lower the presser bar lifter,
loosen the
screw® and move the upper
feed lifting
cam@.
Move it rightward to make the stroke of two
feet
be equal
Move
it leftward to make the stroke of
presser foot be smaller.
2.Adjusting the lifting amount
of presser feet
Adjust the lifting amount of two feet to match
the materials to be sewm.
Loosen the screw @,and move the screw
upward to increase the lifting amount
of
move the screw downward to decrease the
lifting amount.
3.Adjusting the forward /backward clearance
of the two feet
To keep the front groove of walking foot not
strike the rear of the presser foot,the
clearance
of C must be kept about 3mm.
Loosen the screw of feed arm R,and then
turn the feed rock
shaft@ to adjust.
4.Adjusting the feed amount
of walking
foot (Fig.A)
*The standard ration of feed amount between
feed dog and walking foot
is 1:1
The feed amount
of walking foot can be
adjusted to suit for the materials to be sewn.
Loosen the
nut (]),and move the slide block@
Upward:decrease the distance Lto make the
feed amount be smaller
Downward:increase the distance Lto make
the feed amount be larger
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

131. Adjusting the trimming mechanism(Fig.29)
1.Trimming mechanism(Fig.29)
Solenoid
Holder,F-knife Spring Solenoid base
Holder M-knife
Monable knife
Thread trimmer cam lever shaft pring
Driven crank Driven plate Positioning block
Cam lever,L Cam lever,R Stopper plate
2. The relation between fixed knif and
movable knife(Fig.30)
(l)The clearance between fixed knife CD
and movable knife ® shoule be 0.3mm
(2)Adjustthe
position illustrated by the Fig.30
(3)Move the bobbin case opener and adjust
the holder offixed knife.
3.Thread trimmer cam lever
shaft:(Fig.31)
(l)Install the shaft CD on the machine bed
first;
(2)Install the cam lever
Lon the shaft: CD
as illustrated;
(3)Slightly turn the shaft
CD ,and install
the positioning block ®
as illustrated.
-15-
0. 3nvn
r
Spring Cam lever, L Cam lever,R
87 . 5,m,
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

I;
6mm
A
Driven crank
3mm
B
A
-16-
4. Installing the trimming solenoid(Fig . 32)
(l)The stoke of solenoid
a.The standard stroke is 6.0mm
b.Turn the
nut (A) to adjust the stroke
(2)Installing the solenoid
a.Fixed the solenoid by the screw Band
C;
b.Be sure to keep the clearance between the
driven plate
CD and cam lever R® 1mm;
c. When the solenoid is active,there should be
a 0.5mm clearance between the cam lever L ®
and cam lever R ®· If need to adjust,please
move the solenoid base shown by the arrow.
5.Installing the trimming cam(Fig.33)
(l)Align the second markA on the machine
pulley with the Positioning Mark
on the arm;
(2)Set the solenoid active and turn the
trimming cam CD until the cam is touched
with
the roller,then fix the cam;
(3)Set the solenoid inactive and make the
cam lever ® restore to the original position,
there should be a
0.5-1.0mm clearance
between cam and roller.
6.Adjusting
the knices(Fig.34)
(l)The relation between fixed knife and
movable knife
The clearance between movable knife
CD and
needle center is 7.Smm,and
the clearance
betwwwn fixed knife ® and needle center
is
5mm.
(2)Set the solenoid active,the movable
knife
CD will turn rightward driven by the
trimming cam.
When the movable knife
CD moves to its left
furthest position,the clearance between two
knives
CD and ® should be 1.5-2.0mm
(3)Adjusting the trimming solenoid
A.If the thread trimming notsmoothly,
especially the thick thread used,just
need to
increase the trimming pressure;
B.Adjusting the trimming pressure:loosen
the nut B,adjust the screw A
to get the
reasonable pressure.
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

132. Clean(Fig.35)
1.Raise the presser foot;
2.Renove the two screws CD and needle
plate®;
3.Clean the feed dog with a soft brush;
4.Install the needle plate ® by two screws
CD.
5.Turn the machine pulley slowly and check if
the needle drops into the hole center of needle
plate
*If not
• Check
if the needle is bent
• Loosen the screw CD, and reinstall the
needle plate®
6.Turn the machine pulley and lift the needle
above the needle plate,check if the needle
tip is blunt,if yes,change a new one.
7.
Tilt back the machine head
8.Remove
the bobbin case @
9.Clean
the hook with a soft cloth and
check if the hook is worn out
10.Take out the bobbin from the bobbin case,
and clean
the bobbin case with a soft cloth
11.Insert the bobbin into the bobbin case
and place the bobbin case back into the
machine
12.Clean the dust on the filter (A) of
oil pump.
-17-
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com