Sewing machines Made Easy

The Humble Needle

by Les Godfrey

Just like the sewing machine, the needle has undergone many years of continuous�development.� Was the first needle made from a bone or a sharp stick?� Whatever the answer the first obvious improvement was a hole cut into one end allowing sinew to�be threaded through hides and such.� With this simple device we have the two main features of today�s hand sewing needle, possibly one of man�s earliest tools.� The�needle continued its development along with the invention of the sewing machine.� In�fact, it is fair to say that the two evolved together.� The major breakthrough came when�the hole (eye) moved down to the point, an essential characteristic in the achievement�of a working machine capable of producing either a lockstitch or a chain stitch.��

The needle is an integral part of the sewing process.� Obvious you say, but consider this.�Not only is the needle there to pass the thread through the fabric, it is also part of the�stitch construction mechanism. A needle is made up of several parts each as important�as the other.�Starting at the top we have the shank, the thick end.� Early needles were�usually the same thickness from top to bottom and the thicker shank was incorporated�to strengthen the needle as speeds increased and heavier fabrics needed to be sewn.� Depending on the needle system (type of needle) and there are a couple of thousand,��the shank will either have a flat side or be completely round.� Most domestic sewing�machines now use a needle with a flat-sided shank, it is this feature that positions the�needle correctly in the sewing machine ensuring it faces the right way.� Next is the long groove, which runs from the shank down to the eye.� This groove is at the front of the�needle and is opposite the flat on the shank.� At the end of the groove is the eye�followed by the point.�Believe it or not there are different eyes and points.� Above the��eye at the back of the needle, opposite the groove, is the scarf - a short indent or�concaved surface.�Some needles have a second short groove or perhaps other�components but those listed above are the main features.� All of these components have�an important function in forming the stitch.�

See illustration.

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The stitch formation takes place in this order: the needlepoint must first penetrate the�fabric allowing the eye to carry the thread through the fabric.�The fabric in turn pushes�the thread into the long groove.�The groove holds the thread tight at the front of the�needle as the needle descends.�When the needle reaches its lowest position, called�bottom dead centre, it starts to rise.�This causes the thread to throw a loop at the rear,� opposite the groove.�This happens because the thread is being held by the groove at�the front.�This loop forms at the scarf, which is fundamental to the stitch formation�allowing the hook to pick up the thread.

Now that you are aware of these design rules what if you unintentionally put the needle�into the machine back to front?� A direct result would be the loop forming on the wrong�side of the needle for the hook to pick up, resulting in mis-stitching, tangling and�possible thread breakage.� The needle is indeed an integral part of the sewing process�and therefore must be fitted correctly.��

The needle height is also critical.� When the needle is fitted into the needle clamp it must�be pushed up all the way until it touches the stop.� If on an older machine there is no�needle stop the needle height must be set, usually by way of a guide line on the needle�bar.� The needle bar is raised so that the guide line is level with the top of the machine�casting and at this point the needle is set (tightened) so that the eye is level with the�needle plate.� If a guide line is not visible set the needle height by the shuttle.� Check�the height of the needle when the shuttle point is directly behind the needle, it should��be approximately one eye height above the eye.�

Another important element is the correct thread size, in relation to the needle.� A thread�that is too thick for the needle will not stay in the long groove or cannot enter the groove

in the first place.��

A blunt or damaged needlepoint can cause a miss stitch by making a bigger hole in the�fabric thus not allowing the fabric to push the thread into the groove etc..� The correct�needlepoint must also be selected for the fabric e.g., for knitted fabric (stretch) a stretch�needle must be used.� A stretch needle does not have a sharp point but rather a rounded�� point.� It is this feature which makes it possible to sew knitted fabrics without damaging the fabric which in turn would cause a miss stitch.�The rounded point pushes aside the fibre.� Importantly it does not cut through the fibre.� If this were to happen and it being a knitted fabric it would cause a run.�This run would cause too big a hole to form and this would result in a miss stitch.��

On most modern domestic machines the needle is fitted with the flat side facing towards�� the back of the sewing machine and is threaded from the front.� Older machines could�have the needle fitted either with the flat to the back, left or right.� If there is no flat the�long groove is the identifying feature and will determine which way the needle must face.�The scarf is not always present on early needles.� Remember it is the long groove that�holds the thread at the front of the needle allowing the loop to form on the correct side,�which by necessity is where the hook or shuttle will, if everything else is right, enter the�� loop.�� Determine which way the long groove must face by checking which side of the needle the hook or shuttle will pass.� This must be on the opposite side of the long groove.� The needle is then threaded from the side with the long groove.�

If you are wondering about the terminology �Hook� and �Shuttle�, generally a Rotary� Hook machine is said to have a Hook and a �T.S.� (Transverse Shuttle).� A �V.S.� (Vibrating Shuttle) type machine is said to have a Shuttle.� To complicate things a little more the C.B. (central bobbin) type machine, e.g. class 15 Singer, is known as a Shuttle Hook or a C.B. Hook.��

There are many reasons for miss stitching but assuming the sewing machine is in perfect mechanical condition it comes down to the correct needle choice and fitting.

Earlier I mentioned different needlepoints and eyes.� Well there is another element often overlooked - needle size or thickness.� Domestic sewing machine needles are available in�sizes� 60, 70, 80, 90, 100, 110, and 120.� Size 100 being 1mm thick, 120 being 1.2mm,��down to 60, being 0.6mm of 1 mm.� Therefore, the rule is the larger the number the�thicker the needle.� Everyone knows or should realise that a needle size of 100 used in�a fine fabric such as chiffon will not only damage the fabric, it will more than likely�cause miss stitching.� Remember the groove in the front of the needle?� Well it can only�hold the thread tight if the fabric is capable of pushing the thread into it and this can�only happen if the hole in the fabric is small enough to grip the needle.� If the thread is�not held in the groove at the front of the needle when the needle starts to rise the loop�will not form, or a small loop may form on both sides of the needle too small for the�hook to pick up.� This will not happen at every stitch, it depends purely on the hole�made by the needle.

There are numerous mechanical faults that will cause stitch problems, shuttle timing to mention one.� However, what I have attempted to do in this article is unlock the mystery�of that dark area below the needle plate.� You should now be able to work out which�way the needle must face in your machine and knowing that you also know which way�the needle is to be threaded.��

One of man�s earliest tools has come a long way, it has helped clothe us, keeping us warm and dry.�In relatively recent times it has kept thousands of people gainfully employed within a vast industry - the textile trade.��

The Humble Needle

Les Godfrey