Tuesday, July 22, 2008

Featherweight Tension Adjustments by Alex Sussex

Featherweight Tension adjustment by Alex Sussex



From: AlexSussex@aol.com
Subject: LOWER TENSION ADJUSTMENT PART ONE, ALEX ENGLAND
Hi all,

I am sending this message in two parts so look for the second part and join
them up for a complete guide.
Now that I have caught up a little I can get back to putting a few things on
the digests. Today I am going to talk about one of the most misunderstood
parts of the sewing machine.

LOWER THREAD TENSION ADJUSTMENT.
Only the brave or the foolish should read on. In many instruction manuals it
will say something like, the lower tension is set at the factory and should
not be adjusted. That is all and well, but twenty years have passed the
factory closed and your tensions are all over the place, you have got sewing
to do and you want it right.

At the tender age of seventeen one of my masters took me through the basics
of tension adjustments, then spent the next twenty years trying to hammer it
into me how important it is to every sewing machine ever made. No matter if
you have the latest all singing all dancing computer that talks to you and
does the washing up for you or a hundred year old antique that simply looks
lovingly at you but wont perform.

If you are having trouble with your sewing machine stitch quality and you
have done all the usual things, like played around with the top tension for a
week, thrown the machine out of the bedroom window and then tried to see if
it will still work before telling your husband that you were burgled and the
thieves dropped your machine whilst escaping. There is the possibility that
the lower tension of the machine is out of balance. Now before we go any
further, do not, I repeat, do not adjust your machine if you are happy with
your stitch. a simple test if your tensions are well balanced is to sew a
piece of cotton fabric about six inches in length, then get the ends of the
thread that are left and give them a sharp tug. Now if the tensions are good
the thread should snap without pulling out of the work, in other words you
have a proper LOCK STITCH. If you find that the thread is pulling out of one
side or the other then you are out of balance and your threads are not locked
into the fabric, leading to a weak seam. Tension balancing is a little
understood procedure and many so called repair people will mess around with
the wrong part of your machine and make little or no improvement. How many of
you have taken your sickly machines into a shop for a service and received
them back smothered in oil and not much better with a nice bill for nothing.

Well, here goes I will try and explain the enigma that has eluded people for
so long. Even the great inventor Isaac Singer had terrible trouble getting
the tensions right on his first patent model, so you are not alone. The
classic symptoms of lower tension collapse are quite obvious. Look at your
stitch and see if the lower thread has pulled through to the top of the
fabric, the underneath will look fine perhaps a little loose, however the top
thread will be able to be pulled out of the fabric. This is because the lower
thread is laying on the fabric, not pulling the top thread into the fabric.
You will notice with this symptom that you have little or no effect by
altering the top tension dial and often think that it is a top tension dial
fault.

O. K so here goes, hold on tight it is going to get nasty, have your
painkillers ready. Step one, setting the top tension. Assuming that your top
tension is working can be a fatal flaw but is easily checked. Most sewing
machines even quite early ones have automatic top tension release mechanisms.
This means that once the sewing foot is raised the top thread tension is
automatically released so that you can pull your work out of the machine
without the thread breaking. To test this simply raise your sewing foot and
see if the thread pulls out easier than if it were lowered ready for sewing.
To test if the thread is being held by the tension discs properly when ready
for sewing, you need to pull the thread from where it comes out of the eye of
the needle-with the foot lowered. The thread ON ALL MACHINES should be tight
enough to bend the needle when pulled. If it does not then you need to
investigate why it is not tight. The most common reason is a restriction
between the tension discs themselves, caused by fluff, corrosion or trapped
threads. a loose top thread leads to a bunching of thread UNDERNEATH the work
(or looping on minor tension failure). Once you have done this put your
numbered tension dial half way, for instance if you have a dial that goes
from one to four put it on two, one to nine put in between the four and five,
get the idea. on older machines with no tension dial numbers turn the dial
clockwise until the thread bends the needle when pulled through as I have
mentioned earlier. Then leave the top thread tension alone. Well, by now only
the mad will still be with me the brave and the foolish have gone out for
pizza, and we have not even got to the lower thread tension that we are going
to discuss. That will be part two further down the digest.
ALEX SUSSEX
SEWING MACHINES
EASTBOURNE ENGLAND

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From: AlexSussex@aol.com
Subject: LOWER THREAD ADJUSTMENT PART TWO, ALEX, ENGLAND

This is the second and final part of lower thread adjustment.
Now the lower tensions fall into basically two types for lock stitch
machines. Ones with bobbin cases and ones without. We have to deal with each
separately but both have common symptoms and cures. So I will take the
machines with bobbin cases first. It is important to say at this stage that
sewing threads alter a great deal in thickness and stickyness (that is
definitely not a word but you know what I mean). I once had a call out to
Brighton District General Hospital because twelve machines had all broken
down on the same day, only to discover it was a faulty batch of new thread.
If you look closely at, for instance a new polyester and put it against an
old reel of cotton, you know the one that you just could not throw away from
your grannies old stuff because you might just need a sunset orange thread
one day. You will notice that the new polyester can be up to half the
thickness of the old cotton. In simple terms this means that by switching
from polyester to the old cotton you have instantly changed the thread
tension by a huge amount and this can lead instantly to a poor stitch. How
many times have you put your trusty old sewing machine away working
perfectly, and a few days later it is messing about. What you have not
realised is that it is possible that the change in thread has caused this
problem. Some sticky old cottons are only fit for hand sewing or tacking or
winding onto your husbands fishing reel so that he can tell you of the
monster that got away. Always keep a reel of new White thread handy and if
your machine plays up switch to it and see if the stitch is better, nine
times out of ten the thread is the culprit and you just have to be brave and
bin it, or chuck it at a neighbours cat that has just dug up your flower bed
(perfect weight and size for that, so I am told). Now where was I, Oh yes
back to the all important bobbin case thread adjustment. Wind a full bobbin
of new white thread the same type that you normally sew with, it is not
important if it is silk, cotton, polyester or a mix, just your usual thread.
Place the bobbin into the bobbin case and suspend the bobbin by the thread,
like a spider hanging from a thread. It is not so important which way you put
the bobbin into the case, some find a machine sews better with the bobbin
going one way some the other, only trial and error points this out for your
machine (loads of people are going to disagree with this, never mind). Now
whilst the spider, opps, bobbin and case are suspended by the thread simply
jerk your hand a little and see what the case does. Now we are getting to the
nitty gritty of tension adjustment the real bread and beans of the matter. If
when you hold the thread the case simply drops to the floor you need to
adjust the bobbin case screw clockwise until it just holds its own weight, So
that when you shake it a little it drops a little. This is the MAGIC point
known in the trade as the balance point for your type of thread. If the case
does not move you need to adjust the bobbin case screw anticlockwise until it
drops a little accordingly. Once you have mastered this adjustment you will
be in great demand at all sewing classes as you transform misbehaving sewing
machines in an instant. Hold on I am not finished, no happy dancing just yet,
no running out and buying twenty lottery tickets because you feel lucky
(remember me if you win). Although this is the balance point some machines
need to be adjusted slightly tighter or looser for the perfect stitch. When
adjusting from this point make only very small movements of the screw, about
one sixteenth of a turn at a time. After each adjustment run a trial stitch
and examine. Once you are nearly right you can go back to the top tension
unit again and make final adjustments say from a four to a five to get it
just perfect.

Adjusting the newer type plastic cases that are set permanently into the
machine, you know the ones where you just drop in the bobbin and hook it
around the spring plate is much the same. You need to do this more by feel,
you need to FEEL the thread resistance by pulling the thread. One of the ways
to do this is to place a fine hand sewing needle into a cork (pinch one of
your husbands or better still open up a new bottle of wine with dinner) so
that about two inches of the needle is protruding from the cork. Then tie the
thread from the machine case through the eye of the needle and whilst holding
the bottom of the cork pull the thread. Now it should have a slight
resistance and slightly, only slightly bend the needle. Once again if it does
not you need to tighten the case adjustment screw clockwise. If it bends to
much you need to loosen it a touch, remember tiny adjustments only.
well, hey presto that is it, if you can master lower thread adjustment you
will have a control of your machine rather than it controlling you. One final
point (by now the painkillers for that pounding headache have started to
work) if you mix your threads it is a lottery whether the tensions will work
effectively. The worst culprits are the old wooden reels of cotton that can
become hard, springy, weak and sticky they can really mess up your sewing
machine, big time. Try and stick to the same threads, if in doubt about a
thread, bin it, really all the grey hairs and profanities it can cause is
just not worth it.

I hope this has helped any of you that have a tension problem. It has taken
me three hours to type out and explain something that really only takes a few
seconds to perform. Now you know why instruction books hardly ever mention
lower thread adjustments.

One final note, thank you all for the wonderful comments about the millennium
calendar, it has made all the hard work worthwhile, and NO, NO, NO I will not
be doing another, it gave me way too many grey hairs.

From ALEX
SUSSEX SEWING MACHINES
EASTBOURNE
GREAT BRITAIN
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