Harbor Freight Tools 3914 User manual

SEWING MACHINE - SINGLE NEEDLESEWING MACHINE - SINGLE NEEDLE
SEWING MACHINE - SINGLE NEEDLESEWING MACHINE - SINGLE NEEDLE
SEWING MACHINE - SINGLE NEEDLE
ASSEMBLY AND OPERATING INSTRUCTIONS
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit ourWeb site at http://www.harborfreight.com
Copyright © 2003 by Harbor Freight Tools®. All rights reserved. No portion of
this manual or any artwork contained herein may be reproduced in any shape
or form without the express written consent of Harbor Freight Tools.
For technical questions and replacement parts,please call 1-800-444-3353
03914

Page 2SKU 03914
Specifications
ITEM DESCRIPTION
Machine Type Heavy duty, industrial sewing machine; high
speed, single needle-lock stitch
Drive V-belt driven
Action Foot pedal operation, along with a knee and manual lifting arm for presser foot. Presser
tension adjustment
Sewing Thickness 5/16 inch maximum
Feed Type Link style needle feed reduces slippage
Sewing Directions Forward and reverse feed
Stitching Speed 5500 Stitches per minute
Motor Type Clutch motor; 3450 RPM, 5.8 amps, 110 VAC at
60 Hz; single phase
Overall weight 61.6 lbs
Machine Dimensions 20-3/4 (L) x 10 (H) inches
Accessories
- Screwdrivers
- 3 Bobbins
- Small lubricating bottle with tip
- 10 pack of needles
- Power Switch
Table Stand Kit Table Stand Kit (Model 03929) not included
Save This Manual
You will need the manual for the safety warnings and precautions, assembly instructions,
operating and maintenance procedures, parts list and diagram. Keep your invoice with this
manual. Write the invoice number on the inside of the front cover. Keep the manual and
invoice in a safe and dry place for future reference.
Safety Warnings and Precautions
WARNING:When using tool, basic safety precautions should always be followed to re-
duce the risk of personal injury and damage to equipment.
Read all instructions before using this tool!
1. Keep work area clean. Cluttered areas invite injuries.
2. Observe work area conditions. Do not use machines or power tools in damp or wet
locations. Don’t expose to rain. Keep work area well lighted. Do not use electrically
powered tools in the presence of flammable gases or liquids.
3. Keep children away. Children must never be allowed in the work area. Do not let
them handle machines, tools, or extension cords.
4. Store idle equipment. When not in use, tools must be stored in a dry location to
inhibit rust. Always lock up tools and keep out of reach of children.
Rev 04/03 REV 05/03 REV 03/04
Caution: Make certain that the voltage switch on the motor is set correctly
for your use. See page 6.
This Machine requires oil to be added before use -see page 6 for details.
110/220V,

Page 3SKU 03914
5. Use the right product for the job.Do not attempt to force a small product or
attachment to do the work of a larger industrial tool.There are certain applications for
which this product was designed.It will do the job better and more safely at the rate
for which it was intended.Do not modify this product and do not use this product for a
purpose for which it was not intended.
6. Dress properly. Do not wear loose clothing or jewelry as they can be caught in
moving parts. Protective, electrically non-conductive clothes and non-skid footwear
are recommended when working. Wear restrictive hair covering to contain long hair.
7. Do not overreach. Keep proper footing and balance at all times. Do not reach over
or across running machines.
8. Maintain tools with care. Keep tools sharp and clean for better and safer
performance. Follow instructions for lubricating and changing accessories. Inspect
tool cords periodically and, if damaged, have them repaired by an authorized
technician.The handles must be kept clean, dry, and free from oil and grease at all
times.
9. Disconnect power.Unplug product when not in use.
10. Remove adjusting keys and wrenches. Check that keys and adjusting wrenches
are removed from the machine work surface before plugging it in.
11. Avoid unintentional starting. Be sure the switch is in the Off position when not in
use and before plugging in.
12. Stay alert. Watch what you are doing, use common sense. Do not operate when you
are tired.
13. Check for damaged parts. Before using any product, any part that appears
damaged should be carefully checked to determine that it will operate properly and
perform its intended function. Check for alignment and binding of moving parts; any
broken parts or mounting fixtures; and any other condition that may affect proper
operation. Any part that is damaged should be properly repaired or replaced by a
qualified technician. Do not use if any switch does not turn On and Off properly.
14. Guard against electric shock. Prevent body contact with grounded surfaces such
as pipes, radiators, ranges, and refrigerator enclosures.
15. Replacement parts and accessories. When servicing, use only identical
replacement parts.Use of any other parts will void the warranty. Only use accessories
intended for use with this tool. Approved accessories are available from Harbor
Freight Tools.
16. Do not operate tool if under the influence of alcohol or drugs. Read warning
labels if taking prescription medicine to determine if your judgment or reflexes are
impaired while taking drugs. If there is any doubt, do not operate the tool.

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17. Use proper size and type extension cord. If an extension cord is required, it must be
of the proper size and type to supply the correct current to the tool without heating up.
Otherwise, the extension cord could melt and catch fire, or cause electrical damage to
the tool.This tool requires use of an extension cord with up to 10 amps capability (up
to 50 feet), with wire size rated at 18 AWG.Longer extension cords require larger size
wire. If you are using the tool outdoors, use an extension cord rated for outdoor use.
(signified by “WA” on the jacket).
20. Maintenance. For your safety, service and maintenance should be performed
regularly by a qualified technician.
21. Pacemaker safety warning. People with pacemakers should consult with their
physician(s) before using this product; operation of equipment in close proximity to a
heart pacemaker could cause interference or failure of the pacemaker.
Note: Performance of this tool may vary depending on variations in local line voltage.Exten-
sion cord usage may also affect tool performance.
Warning:The warnings, cautions,and instructions discussed in this instruction manual
cannot cover all possible conditions and situations that may occur. It must be under-
stood by the operator that common sense and caution are factors which cannot be
built into this product, but must be supplied by the operator.
Sewing Safety Precautions
1. Keep hands away from the needle when you turn the power switch on, or while the
machine is operating.
2. Do not place your fingers into the thread take-up cover while the machine is
operating.
3. Always turn the machine off and unplug the power cord to the electrical outlet before
tilting the machine head or removing the V-belt.
4. Never leave the machine running and unattended.
5. During operation, never place your head, hair, or hands in the proximity of the hand
wheel, V-belt, bobbin winder, or motor.
6. Do not operate the machine with any safety guards removed.
Unpacking
When unpacking, check to make sure that the parts shown in the photo on the following
page are included. Note that the machine table shown is not included, and must be ordered
separately. If any parts are missing or broken, please call Harbor Freight Tools at the num-
ber on the cover of this manual as soon as possible.

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Assembly
The assembly instructions describe mounting the Single-Needle Sewing Machine (Model
03914) to the Table Stand (Model 03929), not included.In order to complete this procedure,
you must first purchase and assemble the Table Stand Kit (Model 03929).
1. Locate four corner rests in the rectangular hole of the Table Stand where the machine
will sit.
2. Place two rubber seats (A) on the operator-side, corner rests and secure with
supplied hardware (C).See figure 1.
3. Place two cushion seats (B) on the hinge-side, corner rests and secure with supplied
hardware (C).
4. Seat the Oil Pan (D) on the corner seats (A) and (B). See figure 2.
5. Insert Hinges (E) into the opening in the machine bed. See figure 3.
Sewing Machine
Motor
Power Switch
Knee Lifting Arm
for Presser Foot
Table Stand and
Top (not provided)

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6. Fit the machine head to the table rubber hinges (F) before placing the machine head
on the corner seats. See figure 4.
7. Tilt the machine back to expose the Oil Pan (D). See figure 5.
8. Fill the Oil Pan with sewing machine lubrication oil (#7 white oil) to the “high” mark “A”.
Add more oil when the level is to the “low” mark “B”. After lubrication, and during
operation, oil splashing can be seen through the Oil Sight Window (H).
9. Lower the machine head to the table top.
10. Mount the Motor to the underside of the table top as shown below. Use the supplied
hardware.
11. Place the V-belt around the Sewing Machine Pulley, through the slot in the table top,
and around the Motor pulley. Attach the Pulley Safety Cover.
12. Tighten the V-belt tension by adjusting the long bolt and nut at location (K).The
proper tension is reached when the V-belt can only be pushed in 1/2 inch.
(K)
Note:Top switch is for
rotation. Switch left for
counterclockwise;
switch right for clockwise
rotation.
Note: Motoris110/220V
Single Phase. Flip switch
todesired voltage (no
re-wiringneeded).Switch
left for 110V, switch right
for220V.
Note: Receptacle for 6 volt work
light(not included).
REV 04/03 REV 05/03

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13. Mount the Power Switch under the table top, on the operator’s side. Use the supplied
hardware.
PowerSwitch
Mounting theThread Stand
Note: The Thread Stand is designed to be mounted on the Table Stand Kit
(Model03929-notincluded). Unless indicatedotherwise, allpartsreferred
toin this setofinstructionsarelistedin the BobbinWinder&ThreadStand
Unit Parts List found on page 28. During assembly, it will be helpful to
refer to that list and the diagram that follows it on page 29.
14. Locate the large hole in the far right corner (from the location that the operator will be
seated)of theTable(not included). Placethe RubberWasher (45)andWasher (37)onto
the Lower Spool Rest Rod (36) and insert the Rod into the hole mentioned above. Place
anotherWasher (37) over the end of the Rod, and thread on and tighten a Nut (38).
15. Place the Spool Support (46) over the Lower Spool Rest Rod (36) about halfway down.
Insert a Screw (31) and Nut (47) through the Support.
Note: The Support has tabs that hold onto the corners of the Nut to make tightening
easier. When assembling, place the Nut on the side with these tabs.
Tighten the Screw.
16. Insert the threaded end of the Spool Pin (40) through one of the holes in the top of the
arm of the Spool Support (46). Place aWasher (32) and Nut (35) over the end of the Pin
and tighten. Place the Spool Rest (41), Spool Mat (42), and the SpoolVibration Stopper
(39) over the end of the Spool Pin. Repeat this step for both of the Spool Pins (40).
17. Place the Column Pipe Connector (33) over the top of the Lower Spool Rest Rod (36)
until the Rod is about halfway through the Connector. Place a Screw (34) and Nut (35)
through the bottom hole in the Connector and finger-tighten.
18. Place the Upper Spool Rest Rod (30) into the top of the Column Pipe Connector (33).
Place a Screw (34) and Nut (35) through the top hole in the Connector.Tighten all of the
Screws and Nuts in the Connector.
19. Place the Thread Hanger (28) about halfway over the top of the Upper Spool Rest Rod
(30). Insert a Screw (31) and Nut (47) through the Hanger as explained in the note in
step 14, above. Tighten the Screw and place the Column Cap (29) over the end of the
Upper Spool Rest Rod (30).
REV 03/04

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Mounting the BobbinWinder
Note: Unless indicated otherwise, all parts
referredtointhis set ofinstructionsarelisted
in the Bobbin Winder & Thread Stand Unit
Parts List
found on page 28. During
assembly, it will be helpful to refer to that list
and the diagram that follows it on page 29.
20. Remove the Belt Cover (part 4, on page 27). Swing the
sewing machine so the base is in the operating position,
resting on the table. Set the Bobbin Winder to the ‘ON’
Position-see
ON Position, below.
21. Make sure the Bobbin Winder is in the ‘ON’ position.
Position the Base (Bobbin Winder Base Assembly) (1) so
that theThreadWinder Assembly (3) lines up with and just
touches the belt. Mark pilot hole locations on the table at
the far end of each of the two channels in the Base as
indicated in Figure A .
22. Set the Base (1) aside and swing the sewing machine out
of the way. Carefully drill straight pilot holes for each of the
two locations marked above. Place the base in location
andsecure usingtwoWood Screws (26)andWashers(27).
Leave the Screws just loose enough to allow the Base to slide.
23. Swing the Sewing Machine back into it’s operating position. Put the Bobbin Winder in
the ‘OFF’ position-see OFF Position, below.. Slide the Bobbin Winder Assembly close
tothebelt untilitjustbarely doesn’ttouchit(1/8”gap orless)-see FigureB ,above. Tighten
theWood Screws (26) from step 22, above.
24. Put the Belt Cover back on the Sewing Machine before use.
Operation
Caution: To properly break-in your new sewing machine, and
avoid possible damage to the machine, sew at moderate to slow
speeds for the first 15 minutes of use.
BobbinWinder Operation
The BobbinWinder not only assists in winding thread onto the
Bobbin, but it also makes the belt tight, operating the rest of the
machine. The Bobbin Winder has two positions, ‘ON’and ‘OFF’:
OFF Position The Bobbin Winder won’t contact the belt, causing
the machine to ‘idle’.
WARNING: While the machine is ‘idling’ the needle or
other parts can possibly still move at any time. Shut the
machine off completely before working around the needle
or other moving parts.
REV 03/04
Figure A
Figure B
Mark
Pilot
Holes
Here.
OFF
Position
ON
Position
6
6

Page 9SKU 03914
Figure D
a
b
c
d
Attaching the Needle
1. Unplug the Power Cord from the electrical outlet.
2. Select a proper needle size according to the
thread count and type of material being sewn.
3. Turn the Hand Wheel until the needle bar
reaches the highest point of its stroke.
4. Loosen Screw (2) and hold needle (1) with its
indented part “A” facing exactly to the right in
direction “B”.
5. Insert the needle and push it up until it will go no further.
6. While holding in place, securely tighten Screw (2).
Setting the Bobbin into the Bobbin Case
1. Hold the Bobbin so that the thread exit is to the left,
and push the Bobbin into its case.
2. Feed the thread through slit “A” and pull the thread in
direction “B”. By doing so, the thread will pass under
the tension spring and exit at notch “B”.
3. Verify that the Bobbin rotates in the direction of the
arrow when thread “C” is pulled.
ON Position This position is with the Connecting Rod
(6) pressed, as shown in Figure C . The Bobbin
Winder will put pressure on the belt and cause the
machinetooperate. TheShaftonthe BobbinWinder
will also spin; winding thread onto the Bobbin, if the
Winder is set up to do so.
WindingThread Onto the Bobbin
1. Place a Bobbin onto the Bobbin Winder Shaft (5) as
shown at point
d in Figure C , right.
2. RoutetheThreadfrom theSpool (notshown)upthrough
the Thread Guide Tube (43,
point a ), the hole in the
Thread Tension Bracket Assembly (18, b ), over and
underthefarsideoftheTensionDisc(21, c ),andconnect
it to the Bobbin ( d ).-See Figure D , right.
3. While the Connecting Rod (6) is pressed (as shown in
both Figures C and D ) the BobbinWinder will be in the
‘ON’position and the Bobbin will fill with thread. When
finished, release the Connecting Rod and the Bobbin
Winder will reset to the ‘OFF’position.
b
d
Figure C
REV 03/04
6
6

Page 10SKU 03914
Threading the Machine Head
Set the thread spool on its holder and guide the thread through the machine as illustrated
below.The numbers in the illustration indicate the threading sequence.
Adjusting the Stitch Length
1. To increase the stitch length, turn the Stitch Length
Dial (1) to the desired number (in millimeters) as
indicated under the scale dot (A) on the machine.
2. To decrease the stitch length, turn the Stitch Length
Dial (1), while pressing the Feed Lever (2).
Adjusting the NeedleThreadTension
1. Turn Tension Adjustment Knob (1) clockwise (A) to
increase thread tension.
2. TurnTension Adjustment Knob (1)
counterclockwise (B) to decrease thread tension.
Adjusting the BobbinThreadTension
1. Turn theTension Adjustment Screw (2) clockwise
(A) to increase bobbin tension.
2. Turn the Tension Adjustment screw (2)
counterclockwise (B) to decrease bobbin tension.

Page 11SKU 03914
Changing theThreadTake-up Spring Stroke and Pressure
1. Loosen Set Screw (2).
2. To increase the stroke, turn theTension
Knob Screw (3) clockwise (A).
3. To decrease the stroke, turn theTension
Knob Screw (3) counterclockwise (B).
4. Loosen Set Screw (2) and pull out the
Tension Arm (5).
5. Loosen Set Screw (4) and remove the
Tension Knob Screw (3).
6. Turn theTension Knob Screw (3) clockwise (A) to increase pressure;or turn
counterclockwise (B) to decrease pressure.
7. Replace Tension Knob Screw (3), tighten Set Screw (4), and replace the assembly.
Setting the Hand Lifter
1. To stop the machine with its Presser Foot up,
turn the Hand Lifter (1) up (A).
The Presser Foot will go up about 1/4 inch and
stop.
2. To set the Presser Foot to its original position,
turn the Hand Lifter (1) down (B).
Using the Knee Lifter, you can get the standard Presser Foot lift of about 1/2 inch.
Setting the Presser Foot Pressure
1. Loosen Nut (2), and turn the Presser Spring
Regulator (1) clockwise (A) to increase Presser
Foot pressure.
2. To decrease Presser Foot pressure, turn the
Presser Spring Regulator (1) counterclockwise.
3. After adjustment, tighten Nut (2).
Adjusting the FeedTiming
1. Loosen Set Screws (2) and (3) on the Feed
Eccentric Cam (1) and properly position the
Eccentric Cam. Retighten the Set Screws.
2. To advance the feed timing in order to prevent
uneven material feed, move the Feed Eccentric
Cam up (clockwise).

Page 12SKU 03914
3. To delay the feed timing in order to increase stitch tightness, move the Feed Eccentric
Cam down (counterclockwise).
Adjusting the Height of the Feed Dog
The Feed Dog is factory adjusted so that it juts
out from the Throat Plate surface 0.8 mm to 0.9
mm. If the Feed Dog juts out too much, pucker-
ing may result when sewing lightweight materi-
als.To adjust the height of the Feed Dog:
1. Loosen Screw (2) of Crank (1).
2. Move the Feed Bar up or down to make
the adjustment.
3. Tighten Screw (2), being careful not to
overtighten.
Adjusting Needle-to-hookTiming
1. Turn the Hand Wheel to bring the needle
bar down to the lowest point of its stroke.
2. Loosen Set Screw (1).
3. When using a DBX1 needle, align to
marker line “A” on the needle bar (2) with
the bottom end of the needle bar lower
bushing (3), then tighten Set Screw (1).
When using a DAX1 needle, align to
marker line “B” on the needle bar (2) with
the bottom end of the needle bar lower
bushing (3), then tighten Set Screw (1).
4. When using a DBX1 needle, loosen three
Hook Set Screws, turn the Hand Wheel,
and align the marker line “B” on the needle
bar (2) with the bottom end of the needle
bar lower bushing (3).
When using a DAX1 needle, align the marker line “D” on the needle bar (2) with the
bottom end of the needle bar lower bushing (3).
5. After making the adjustments in steps 3 and 4, align the Hook Blade point (5) with the
center of the needle (4).
Provide a clearance of .001” to .004” (0.04 to 0.1 mm) between the needle and the
hook.This clearance is less than 1/64” (almost touching). Securely tighten the three
Set Screws. If the clearance is too small, the tip of the hook will be abraded. If it is too
large, it will lead to skip over.

Page 13SKU 03914
Adjusting the Presser Bar Height
1. Loosen Set Screw (1) and manually adjust the Presser Bar
height, and the angle of the Presser Foot.
2. After adjusting, securely tighten the Set Screw (1).
Adjusting theThreadTake-up Stroke
1. When sewing heavy weight materials,
move theThread Guide (1) to the left (A) to
increase the length of thread pulled out by
theThreadTake-up.
2. When sewing lightweight materials, move
theThread Guide (1) to the right (B) to
decrease the length of thread pulled out by
theThreadTake-up.
3. The normal setting is when the marker line
“C” on theThread Guide (1) is aligned with
the center of the screw.
Adjusting the Height of the Knee Lifter
The standard height of the Presser Foot lifted using the Knee Lifter is 0.39 inch (10 mm).
1. To adjust the Presser Foot lift up to 0.5 inch (13 mm), adjust the Screw (1).
2. When the Presser Foot lift is adjusted over 0.39 inch (10 mm), be sure that the bottom
end of the Needle Bar (2) does not hit the Presser Foot (3).
This can be manually checked by turning the Hand Wheel.
Maintenance
1. Machine adjustments should only be performed by a qualified technician.
2. Check the oil level weekly when the machine is used daily. Add sewing machine oil as
required to the high level marking.
3. Clean the machine with a clean, damp cloth. Do not use solvents or thinners.
4. When not in use, cover the machine and store in a clean and dry location.

Page 14SKU 03914
Ref. Amt.
No. Part No. Description Req.
ARM BED PARTS LIST

Page 15SKU 03914
PLEASE READTHE FOLLOWING CAREFULLY
THEMANUFACTURERAND/OR DISTRIBUTORHASPROVIDEDTHEPARTS DIAGRAMINTHIS
MANUAL AS A REFERENCE TOOL ONLY. NEITHER THE MANUFACTURER NOR DISTRIBU-
TOR MAKES ANYREPRESENTATION ORWARRANTY OFANY KINDTOTHEBUYERTHATHE
OR SHE IS QUALIFIED TO MAKE ANY REPAIRS TO THE PRODUCT OR THAT HE OR SHE IS
QUALIFIED TO REPLACE ANY PARTS OF THE PRODUCT. IN FACT, THE MANUFACTURER
AND/ORDISTRIBUTOREXPRESSLYSTATESTHATALLREPAIRSAND PARTS REPLACEMENTS
SHOULD BE UNDERTAKEN BY CERTIFIED AND LICENSEDTECHNICIANS AND NOT BYTHE
BUYER. THE BUYER ASSUMES ALL RISK AND LIABILITY ARISING OUT OF HIS OR HER
REPAIRS TO THE ORIGINAL PRODUCT OR REPLACEMENT PARTS THERETO, OR ARISING
OUT OF HIS OR HER INSTALLATION OF REPLACEMENT PARTSTHERETO.
NOTE: Some parts are listed and shown for illustration purposes only and are not available
individually as replacement parts.
NOTE:When ordering parts from the following lists, always include the
list title, item number and description, and page number.For example,
to order the first part from page 14 list, you would state:
- Arm Bed Parts List
- Item #1 - Arm Bed Assembly
-Page:14
ARM BED ASSEMBLY DRAWING

Page 16SKU 03914
Ref. Amt.
No. Part No. Description Req.
MAIN SHAFT THREAD TAKE-UP PARTS LIST

Page 17SKU 03914
MAIN SHAFT THREAD TAKE-UP ASSEMBLY DRAWING

Page 18SKU 03914
Ref. Amt.
No. Part No. Description Req.
FABRIC--PIERCING HOOK DRIVING PARTS LIST

Page 19SKU 03914
FABRIC--PIERCING HOOK DRIVING ASSEMBLY DRAWING

Page 20SKU 03914
Ref. Amt.
No. Part No. Description Req.
PRESSER BAR PARTS LIST