Professional Sewing Machine
can not be over emphasized.
The number one reason sewing machines breakdown
is neglect. But you can remedy this situation
and save hundreds of dollars all at the same
Now discover the secrets of
sewing machine repair for yourself. This
ecourse is designed to lead the beginning sewer
step by step to understanding how the sewing
machine works, how to maintain it, and how to
service it. This 240 page ecourse comes loaded
with sewing machine resources and
To guide your learning, a
step by step workbook is provided with the
reveals the tips and tricks
the pros use to maintain, service, and repair
A special collection of
manufacturer's parts and service manuals are
provided for educational purposes to help you
learn the essentials of sewing machine
To Learn More About This
For even more on sewing
machine repair of antique sewing machines,
sergers, and embroidery machines -----
HOW DO YOU
ADJUST THE BOBBIN TENSION?
When you learn how to sew
many sewing machine users overlook the
essential skills required to adjust bobbin
tension. This is a critical part of
knowing how to sew.
Tensions are a common source of problems in
sewing. Understanding how tensions work is
essential for every sewing machine user. It is
not as complicated as some believe, and not as
simple as some might think.
Tension is the amount of
drag or resistance on the thread as it moves
through the sewing machine. When the tension on
top and on bottom are balanced properly, the
threads will join in the middle of the fabric
with no excess thread on top or the bottom of
The thread on the top of the
sewing machine is threaded from the thread
spool over and through a series of thread
guides, through the tension assembly (a set of
discs with adjustable pressure on the discs),
through the take up spring, through the take up
lever, and finally through the eye of the
needle. There are minor differences in how
sewing machines are threaded, but there is
amazing similarity too.
1. Make sure the thread on the spool is evenly
flowing off the spool.
2. Follow the prescribed thread line through
3. Look for any abnormality that might snag the
thread. Fix it.
4. Always thread the take up spring and take up
5. Thread the needle as manufacturer
recommends. Most thread front to back, but some
older machines thread right to left or left to
6. ALWAYS thread the machine with the presser
foot UP until you are ready to thread the eye
of the needle.
7. Test the thread tension with the presser
foot up. Make sure it easily flows through the
8. Put the presser foot down and thread the eye
of the needle.
9. Test the thread flow by gently tugging on
the thread. Avoid bending the needle. You
should feel a serious drag on the thread.
10. Lift the presser foot and retest. There
should be little or no resistance.
The upper thread tension is
adjusted by tightening or loosening the tension
adjusting knob. You may have been told that on
your machine, the tension is right when the
knob says 3 or 4. This is not necessarily true
as we will soon see.
The lower thread system is
even a little more mysterious than the upper
thread system, but it is in many ways even more
simple. The lower thread system may involve top
loading bobbins, front loading bobbins, or even
side loading bobbins. Older machines often used
shuttles mounted underneath the machine. While
there are a variety of different designs, the
essentials are the same. Thread is wound on a
bobbin (older machines used shuttles the same
way). The bobbin is placed into a case or
holder. The thread in the bobbin is drawn
through a tension device and up to the top of
the sewing platform.
1. Be sure you have the right bobbin.
2. Be sure the bobbin thread is properly
3. Be sure to place the bobbin in the bobbin
carrier exactly the way your sewing machine
manual says. The bobbin thread usually moves
from left to right or clockwise around the
bobbin as it turns.
4. Thread through the lower tension. Usually,
this means the bobbin thread will peal back
through the bobbin tension rather than follow
along or just flop in the wind. Notice the
piece of metal on top right of the carrier. A
small metal spring usually built into the
bobbin carrier applies pressure or resistance
to the bobbin thread. This is the bobbin
tension spring. A tiny screw holds the tension
spring in place. Turning this screw to the
right will tighten the lower tension. Turning
it to the left will loosen the bobbin tension.
(“Righty Tighty, Lefty Loosey”)
5. Some bobbin carriers are built in, but many
are inserted after loading the bobbin.
a. In the later case, test the tension by doing
the following. Pull off about six inches of
bobbin thread through the tension. Dangle the
bobbin carrier with the bobbin in it while
holding the thread above it. The lower tension
should hold the carrier so that it does not
drop. If it does, just turn the screw a quarter
turn to the right. If it does not drop, try
bouncing the carrier a little. If the tension
is properly set, the carrier will drop a little
and stop. If it does drop a couple of inches
and stops, all is good. If the carrier does not
drop at all even after pretty good bounce, the
tension is too tight. Turn the screw a quarter
turn to the left. Try again.
b. Many machines have a drop in bobbin that
fits into a bobbin carrier below the needle
plate. Once the bobbin is placed in the
carrier, the thread is drawn under a tension
spring. The same gentle pull test used in the
front loading bobbin can be used with the drop
in bobbin, but it is a bit less precise. If you
continue to experience difficulties with the
bobbin tension, it may be adjusted by turning
the small tension screw on the spring of the
bobbin carrier. You may also seek the expert
assistance of your local sewing machine
technician if needed.
6. Make sure there are no snags in the thread
line after you bring the thread up through the
needle plate hole.
When the thread from the top
and the thread from the bottom meet and form
stitches in the center of the fabric with not
excess thread on top or bottom, tensions are
said to be balanced.
Think of your fabric like a
stream of water. There are two teams with ropes
(threads) tugging in opposite directions. Sew a
straight stitch seam four or five inches long.
Look at the thread. Where does the stitch tie
off or connect? Do you see small loops,
nubbies, or other signs of excess thread on the
top or bottom of the thread. The team that
pulls the hardest wins the excess thread. If
the upper tension is tighter than the lower
tension, excess thread will appear on top of
the fabric. If the bobbin tension is tighter
than the upper tension, you will see excess
threads underneath the fabric.
To balance the tensions,
simply adjust the upper tension in relation to
the lower tension. If you have tested the
bobbin tension as indicated above, you should
not have to adjust the bobbin tension unless
you significantly change the size of
If there is excess thread on
the bottom of the fabric, increase the tension
on top by turning the adjustment knob to a
larger number (usually turn clockwise). If
there is excess thread on the top of the
fabric, decrease the top tension by adjusting
the tension knob to a lower number
If you continue to have
tension challenges, take the machine to your
local sewing machine service center for a
Important When You Have
1. Rethread & Double Check threading.
2. Test lower and upper tensions as you
3. Test sew and adjust upper tension – increase
4. Have a professional sewing machine
technician service the machine.
When you learn how to sew many sewing machine
users overlook the essential skills required to
adjust bobbin tension. This is a critical
part of knowing how to sew.
Donna Trumble is a professional designer,
seamstress, author, sewing educator, and sewing
business owner. She leads several
Sewing Show And Tell groups in her stores
guiding participants to shop sewing machines
and learn about sewing and quilting.
David Trumble is a sewing
professional, author, semi-retired minister,
sewing machine technician, and CFO of Temple
Sewing And Supply, Inc.