EasyManua.ls Logo

SunStar KM-757 - User Manual

SunStar KM-757
35 pages
Save Page as PDF
Print Icon
To Next Page IconTo Next Page
To Next Page IconTo Next Page
Loading...
SSUUNNSSTTAARR MMAACCHHIINNEERRYY CCOO..,, LLTTDD..
1. For proper use of the machine, thoroughly
read this manual before use.
2. Keep this manual in a safe place for future
reference in case the machine breaks down.
User’s
Manual
KM-757
High speed, two needle, drop
feed, needle feed, sewing
machine with automatic
thread trimmer.
KM- 797
High speed, two needle, drop
feed, needle feed, sewing
machine with automatic
thread trimmer for each
needle.
MMMMEE--005500662299

Table of Contents

Questions and Answers

  • S
    Shirley PowellAug 1, 2025
    What to do if the thread keeps breaking on my SunStar KM-757 Sewing Machine?
    • T
      Tony MillerAug 1, 2025
      If the thread is breaking on your SunStar Sewing Machine, consider these potential causes. First, check the threading; incorrect threading (inserted from the wrong side) requires you to thread the needle correctly. A bent needle also leads to thread breakage, so replace it if necessary. Ensure the needle is inserted correctly and at the right height. Adjust thread tensions: reduce upper thread tension if it's too tight, and reduce lower thread tension if it's too loose. Also, adjust the stroke level if it's too large. Finally, check for scratches on the hook edge, feed dog needle hole, or needle plate and remove any scratches found.
  • F
    fwebbAug 11, 2025
    Why does the needle keep breaking on my SunStar KM-757 Sewing Machine?
    • R
      Regina JohnsonAug 11, 2025
      If the needle of your SunStar Sewing Machine is breaking, several factors could be at play. It might be due to incorrect needle insertion; in this case, reinsert the needle correctly, pushing it to its highest level. Alternatively, the needle itself may be bent, requiring a replacement. Issues with the feed dog or the timing between the needle and hook could also cause the needle to break, necessitating adjustments. Finally, interference between the needle and hook heads requires adjusting the hook's location.
  • K
    Karen BlevinsAug 20, 2025
    What to do if the needle is bent in SunStar Sewing Machine?
    • A
      Alexandra KnightAug 20, 2025
      If the needle of your SunStar Sewing Machine is bent, it may cause the needle to break. In this case, you should change the needle.

Summary

Safety Rules for Machines

1-1) Machine mobilization

Safe procedures for moving the sewing machine.

1-2) Machine Installation

Preconditions and steps for machine installation.

1-3) Troubleshooting

Guidelines for troubleshooting machine issues.

1-4) Machine Operation

Essential safety practices during machine operation.

1-5) Safety Device

Identification and purpose of safety devices.

1-6) Position of Caution Mark

Location and meaning of caution marks.

1-7) Content of Caution

Detailed explanations of caution warnings.

Specification

1) Sewing machine

Technical specifications for sewing machine models.

2) Servo motor

Specifications for various servo motor models.

3) 470 motor

Specifications for the 470 motor.

4) 470 motor controller

Specifications for the 470 motor controller.

5) Clutch motor (for non-trimming type)

Specifications for clutch motors.

6) Peripheral automation devices (optional)

Specifications for optional automation devices.

Installation

1) Installation of the machine head

Step-by-step guide for installing the sewing machine head.

2) Installation of knee lifting solenoid and power switch box

Procedures for mounting the knee lifting solenoid and power switch.

3) Oil supply

Instructions for filling and maintaining the machine's oil system.

4) Adjustment of belt tension

How to properly adjust belt tension.

5) Installation of the program unit (Servo motor)

Guide to installing the servo motor program unit.

6) Installation of the belt cover

Steps for attaching the belt cover.

7) Installation of the thread stand

Instructions for assembling the thread stand.

8) Assembly of the location detector and its control method

Guide to assembling and setting up the location detector.

9) Check for the stop position of the sewing machine (automatic thread trimmer)

Verifying correct stop position for thread trimming.

10) Reverse button function (automatic thread trimmer)

Understanding and utilizing reverse button functions.

Adjustment of the Machine

1) Inserting the needle

Correct procedure for inserting a sewing needle.

2) Removing bobbin and bobbin case

Steps for removing the bobbin and bobbin case.

3) Winding the lower thread

Guide on winding the lower thread onto the bobbin.

4) Routing the lower thread

Correct path for threading the lower thread.

5) Inserting the bobbin

Procedure for inserting the wound bobbin.

6) Routing the upper thread

Correct path for threading the upper thread.

7) Adjusting the thread tension

How to adjust upper and lower thread tensions.

8) Adjusting the height and pressure of the presser foot

Setting presser foot height and pressure.

9) Adjusting the needle and feed dog timing

Aligning needle and feed dog timing.

10) Adjusting the height of the feed dog

Setting the correct height for the feed dog.

11) Adjusting the needle and hook timing

Synchronizing needle and hook timing.

12) Clearance adjustment between the upper side of the hook stopper and the upper side of the needle plate groove

Setting hook stopper and needle plate groove clearance.

13) Clearance adjustment between the hook and opener

Adjusting clearance between hook and opener.

14) Operation of needle bar (left, right) stop (KM-797 Series)

Controlling needle bar movement.

15) Adjusting oil flow in the hook and the face plate

Ensuring proper oil lubrication.

16) Adjusting the trimming device

Fine-tuning the automatic thread trimming mechanism.

17) Replacing movable knife and fixed blade

Instructions for replacing trimming device knives.

18) Adjusting the wiper

Setting the thread wiper's position and function.

19) Replacing the gauge set for needle width

Steps for changing the needle gauge set.

Causes of Trouble and Troubleshooting

1) Sewing machine troubleshooting

Common sewing machine problems, causes, and solutions.

Table Drawing

SunStar KM-757 Specifications

General IconGeneral
BrandSunStar
ModelKM-757
CategorySewing Machine
LanguageEnglish

Related product manuals