1) The document discusses an overlock sewing machine, which is a specialized machine used for edge finishing and seaming. It has one or two needles and loopers and uses 2-5 threads to make an overlock stitch. 2) The objectives are to learn about the machine parts, thread path, maintenance needs, and replacement timing of overlock machines. 3) Overlock machines come in 3, 4, and 5 thread versions and have specifications like brand, model, stitches per minute, and needle and looper counts that vary by the number of threads used.

1. OVERLOCK SEWING MACHINE
BOOBALAN.S
DFAD..B.TECH (FASHION TECHNOLOGIST)
UNIVERSAL INSTITUTE OF FASHION DESIGNING
KARAIKUDI

2. INTRODUCTION
There are many types of sewing machines. Some are used for
special purposes such as overlock machine, bar tack machine,
button hole making machine etc. Overlock machine is also called
serger. A serger is an over locker. An overlocker is a serger. This
type of machines works in a cycle and so these are called simple
automatic machine. Here we study on such a type of machine that
is overlock machine. Overlock machines are specialized machines
that make the overlock stitch. The overlock stitch is used for edge
finishing and seaming. Overlock machines come in both home and
industrial versions.

3. OBJECTIVES
 To know about the machine parts of over lock machine.
 To know about the thread path of over lock machines.
 To lean the way of maintenance of the overlock sewing machine
for its longer life.
 To gather knowledge on how and when the replacement needs to
be carried out.
 To acquit ourselves with various machinery tools.

4. SPECIFICATIONS
• Name : Industrial overlock machine.
• Types : 3, 4 & 5 threads
• Brand : JUKI
• Model : MO-3614 (4 thread)
• SPM : 6500-8500
• TPI : 15-16 (3), 17-18 (4) & 21-22 (5)
• Needle no : 1 needle, 2 loopers (3); 2 needles, 2 loopers (4) & 2 needles, 3 loopers (5)
• Needle name : DCX1
• Needle size : 9, 11, 14, 16, 18, 20 & 21

5. Main parts of over lock machine
1. Thread stand
2. Thread package
3. Thread guide
4. Disc type tensioner
5. Thread guides
6. Needles
7. Loopers
8. Thread cutter

6. DESCRIPTION
Mainly over edge machines are Overlock. In this type of
sewing machines there are one or two needles and edge-
trimming knife is at the front of needle. To make over lock
stitch 2-5 threads are used. Usually SPM of over lock
machine is 6500. But SPM of 8500 machines are also
found. In this machine there also stretching (stretching max
1: 0.6) and gathering (gathering max 1: 4) systems during
feeding cloth. Stitch is done up to maximum 4 mm length
and stitch length may also be changed by push button. This
type of machines can be used for sewing for both woven
and knitted cloths.

7. SERIAL
NO
MACHINE NAME
NO OF THREADS USE
TOTAL THREADS
USE
NEEDLE LOOOPER
1 2 Thread Overlock Machine 1 1 2
2 3 Thread Overlock Machine 1 2 3
3 4 Thread Overlock Machine 2 2 4
4 5 Thread Overlock Machine 2 3 5
5 6 Thread Overlock Machine 3 3 6
The Relationship between Overlock Machine and Number of Thread Used

8. Thread guiding techniques for overlock

9. Technical Adjustment of Overlock Machine
Technical adjustments that are to be taught while dealing with OVERLOCK machines are given below.
Trainers should keep the following points in mind during the session of OVERLOCK machine
 First, demonstrate the adjustment then ask trainees to practice on the machine.
 Use the Instructional manual given by the machinery supplier during Session
 Make sure, all the trainees are able to understand the Instructional manual.
 The practice of sewing on a machine is also necessary.

10. Technical Adjustments Points of
Overlock Machine
 Basic Machine Practice
 Technical Specification
 Installation of needle
 Needle bar height adjustment
 Needle to lower looper timing
 Upper Looper Timing
 Chain looper timing (Safety Stitch)
 Upper Knife Adjustment
 Lower Knife adjustment
 Feed Dog height adjustment
 Cam Timing
 Thread Adjustment

11. CONCLUSION
Overlock machines can not be used for normal purpose. But for making a complete garment
their importance can not be denied. Special care and sufficient knowledge is necessary for
proper working. Otherwise faulty sewing may be done. I would like to give special thanks
to our teacher. I am also grateful to our instructors. I think this will be very helpful in my
future life.