Why does not a typewriter scribble. Reasons why the sewing machine does not pick up the bobbin thread and how to remedy them

REASON # 1. The machine needle is installed on the wrong side. If you are a beginner seamstress and your troubles with a sewing machine started with changing a needle, let's first take a closer look at how this needle works and why. The machine needle is a completely brilliant invention of W. Hunt, and it consists in the fact that there are two grooves along the needle: long on one side and short on the other. When this ingenious needle pierces the fabric, the upper thread coming from the spool is hidden in a long groove. This makes the needle and thread very easy to pass through the fabric. On the other hand, the section of the thread, which on the other hand has got a short groove, experiences a lot of friction. As the needle goes down, it pulls the thread along. But with the reverse movement, the section of the thread, which is successfully hidden in the long groove, comes out unhindered. And the thread in the short groove was unlucky: it has nowhere to hide, and it gets stuck, forming a loop under the fabric, which the shuttle grabs. This is how simple (and at the same time very cleverly?) A machine stitch is formed. If you did not attach any importance or simply could not remember which side to insert the needle into the sewing machine (and looking at the instructions every time, even if it hasn’t been lost yet, is so boring!), Then now you will not be confused: the needle must be inserted with a long groove in the direction from which the thread is threaded. Failure to comply with this rule is a fairly common reason why the sewing machine does not sew: the handwheel turns, and the fabric moves under the foot, and the needle makes frequent strikes, and instead of stitching, only a uniform row of holes ... REASON # 2. The new needle is too thin for the thread to be threaded into the sewing machine. The thread does not fit in the long groove, protrudes outward, and the holes in the fabric are too large. The thread from the side of the short groove no longer gets stuck in the fabric or does not get stuck every time. It turns out ugly gaps, or even stitches are not formed at all. Change the needle to a thicker one or a thinner thread, whichever is easier for you. REASON # 3. The sewing machine does not sew because the upper thread breaks every few stitches. See if it gets caught on the threading path: by the tension adjuster spring, by the thread take-up, by the needle tip. Often, a turn of thread, having slipped off the spool, is overwhelmed around the rod on which it is installed, and this is not immediately noticed. Modern cardboard spools behave especially badly. It is advisable to put a smooth plastic circle under them. If it is not included with your sewing machine, cut it out of the bottom of the plastic bottle, and make a hole in the middle with a heated nail.

Many who tried to sew knitwear on an ordinary sewing machine noticed that the machine often refuses to make a beautiful and even stitch. There are gaps in the knitted stitching, the lower thread loops and sometimes breaks. Why is this happening and how can you fix it?

Firstly, a special knitting machine is used for sewing knitted fabrics; it is called a coverstitch machine - a coverstitch or a chain stitch machine. The seam on the reverse side looks like a "pigtail". Look at any T-shirt factory processing and you will be convinced of it.

Secondly, a knitted overlock is used for stitching cuts of knitted fabric, which has a differential (stretching fabric) rail with simultaneous laying of a sewing chain stitch.

And thirdly, special needles and threads are used for sewing knitwear. The last point is decisive for your sewing machine, so let's figure out what kind of needle you need to sew knitwear, what threads you need to use to get a high-quality stitch, and consider other factors that affect the quality of the stitch.

Needles for sewing knitted fabrics

There are many reasons that affect the quality of the stitch formed when sewing knitwear. One of them is the wrong needle. Universal needles, which are most often used on sewing machines, are “poorly” suited for sewing knitwear. Not only can the sharp edge of the needle damage the weave of the knitted fabric, it can also be the cause of a too small loop near the eye of the needle. And the nose of the shuttle just goes past it without grabbing the top thread. As a result, gaps appear.

Replace the multipurpose needle with a special round point needle designed for these fabrics. A needle with such a point does not pierce the fibers of the knitted fabric, but passes between them and creates the best conditions for the formation of a loop. The packaging with such needles is labeled "Jersy", and "ball point" means that the needles have a rounded point.

However, you should be aware that buying a package of special knitted needles does not always solve the problem, especially for old-type sewing machines, such as Podolskaya or Chaika. There are a number of other factors, which will be discussed below.

This pattern shows a knitted weave of stretch fabrics. Outwardly, it resembles knitting or on a typewriter, which is why it is called a knitted fabric. "Springy" loops give fabrics many useful qualities, such as stretchiness, slight creasing, etc., but at the same time create certain difficulties when sewing them on ordinary household sewing machines.

Threads for knitted fabrics and their tension

Not a single lockstitch machine "likes" sewing jersey. The knitwear for the lockstitch sewing machine is a test that not all sewing machines pass. True, modern household machines do this task quite well, provided that certain requirements are met. As you already understood, one of them is a high-quality thread and its correct tension.

Sewing threads should be fine, elastic and strong. Basically, all types of modern threads available from the accessories department meet these parameters. But, nevertheless, you need to empirically determine which type of thread is best for your machine.

Naturally, you need to "forget" about thick finishing threads, and even more so about threads from old grandmother's stocks. Ideally, threads on conical large bobbins are suitable for sewing knitwear, but since they are quite expensive, use threads on small spools, such as "Ideal".

Before sewing knitwear, the upper and lower thread tension must be correctly adjusted.

Normally, the bobbin thread should not be adjusted, but when sewing knitwear this will often eliminate thread looping in the stitching. If the bottom loop does not stop while pulling the upper thread, try to loosen the lower thread tension a little.

Note that when sewing knitted fabrics, the stitching will be looser in one direction (usually crosswise). This “effect” cannot be eliminated by tension. It's just that the knitwear stretches under the influence of the foot and the teeth of the rake, and then it takes its previous shape and the stitches are weakened. By the way, the pressure of the foot must also be regulated.

To eliminate this, use stabilizers (gaskets), including pre-cut strips from the newspaper. Under the fabric is laid paper strip, and then, gently pulled out of the seam. By the way, it is often just such a "cunning" method that can eliminate gaps in the line at the Podolskaya or Chaika sewing machine.

But, naturally, this is too extravagant way, which is undesirable to use. If you have changed the needles and picked up the threads, adjusted the tension, and the looping and gaps have not disappeared, then you need to adjust the sewing machine. But only an experienced craftsman can adjust for sewing knitted fabric.

What is the difference between knitted overlock

Almost all modern household overlocks are knitted overlocks. The main difference between the knitted overlock and the usual one is that the knitted overlock has a special rack device (teeth under the foot). During operation, the rail specially compresses (stretches) the knitted fabric, and after stitching, the fabric is stretched back (pulled together). As a result, the seam is stretchable and can withstand more tensile stress.

For example, if you grind on an ordinary typewriter knitted fabric, and at the same time tighten the thread tension tightly in order to eliminate slack in the stitching, you will get a very beautiful stitch, but not strong. Stretch this section with your hands, and your beautiful seam just burst. This is the main purpose. knitted machines- to carry out an elastic and stretchable seam.

Overlocks with a differential rail can sew not only knitwear. This function can be easily disabled using a special handle. And even, on the contrary, you can "force" the rail to collect the fabric. You need to know that overlocks of older models, including overlocks of the 51st class, cannot perform high-quality processing of knitted fabrics. And don't be surprised if the joining seams knitted clothes processed with only a three-strand overlock will burst over time.

Other reasons why the machine does not sew knitwear

And the last thing. The Podolsk sewing machine or the Chaika sewing machine often refuse to sew knitwear at all. And even a master can not always customize it for sewing knitted fabric. If you want to test the work of a sewing machine repairman, ask at the end of the work to sew a piece of the most "harmful" knitted fabric. If the line does not even have one gap, then this is a "good" and experienced master.

Old machines have a different adjustment of the interaction between the needle and the shuttle nose. Indeed, at the time when they were released, no one suspected that such fabrics would be used all the time. Therefore, modern machines are set up for sewing knitwear, and old machines need to be reconfigured.

How to sew knitted fabrics on a conventional sewing machine

How to sew knitwear without a cover plate on a household machine

Even the most expensive, reliable and high-quality sewing machine, like any other technique, can start to work incorrectly or stop altogether. Moreover, a Chinese single-thread machine is prone to breakdowns. Let's figure out why the sewing machine does not sew and how to fix it.

Common problems

The sewing machine has stopped sewing. Whether it is manual or motorized, you may encounter the following manifestations of this breakdown.

The bobbin or upper thread will not feed. The stitching is "scanty" - there is not enough thread in the seam. Zigzag sewing does not work at all.
The fabric does not move as the stitches are sewn. Those, in turn, are layered on top of each other, instead of a seam, a tangled ball is formed, the threads are wasted.
The foot does not work: it is impossible to raise / lower it.
The motor is running, the drive shaft is turning, but the needle bar does not move or has stopped working. Sewing has stopped.
The machine does not show signs of life - the engine does not work, does not light up and does not display information about the operating mode of the display. The work doesn't start.
Crunch, crackle, malfunction of mechanisms, sudden "jerking" of the smooth and smooth running of the machine. Reducing the speed at which the fabric is sewn, which lengthens the time it takes to perform fast and precise actions on their own.
The sewing machine works, but periodically stops closer to the middle of the seam or immediately after starting to lay it over the layers of fabric.
The machine tries to reach the declared speed even when the foot pedal is fully depressed, but it moves with difficulty.

Some faults are grouped by common cause their appearances. Others, on the other hand, have a variety of reasons.

Causes

Some reasons depend on the differences between a particular model and others - even, at first glance, compatible. So, the thread is not picked up from the shuttle by the needle, the seam does not go due to:

wear of the hook tip, incorrect setting (or detuning);
malfunction of the spatial course of the shuttle;
the presence of chipping on the bobbin cap;
incorrect setting of the acupuncture mechanism (too high or low);
the beveled screw holding the bobbin;
out-of-sync between the lower section of the machine and the needle bar.

Most likely, the mechanism itself is malfunctioning. To maintain it, it is recommended to contact a service center for repairing sewing equipment.

Malfunctions of the node responsible for needle guidance are as follows:

the needle and fabric are not compatible (thin needle for thick fabric and vice versa);
selection of a cut-off needle for an industrial machine with a no-cut needle holder (and vice versa);
the flask is too small (it is impossible to pinch the needle, it slips out);
a crooked or blunt needle;
the thread is thicker than the needle, the movement is difficult (the thread breaks, the needle bends and eventually breaks).

The jerky movement of the tissue is due to the following. When the gap in the throat plate is unnaturally widened, worn out, together with the needle, the entire puncture zone of the fabric is tightened inward. This prevents the shuttle from sewing correctly, and the seam ultimately does not contain all the stitches.

It is necessary to check and, if necessary, re-set the correct position of the stapler bar teeth.

When the slats and the needle are out of sync, the fabric wrinkles, the lower thread does not push into the stitches - the upper thread can be overly stretched and torn. In some cases, the bobbin thread may break and stop flowing into the stapler, as a result the seam turns out to be one-thread, simplified, easily dissolves and does not hold the layers of fabric. The use of threads of different thickness is unacceptable. A thicker thread is more difficult to grasp, which is why the seam has a flaw - skipping the lower loops.

Ideally, the bobbin thread should be slightly thinner, not thicker than the top thread, and more stretchable. Excessively twisted threads will also provoke skipped stitches and buttonholes - they are poorly seized by the shuttle.

Remedies

If the sewing machine does not pick up the bobbin thread due to imbalance, adjust the mechanism by setting the correct distance between the needle and the hook tip. Please do the following.

Turn on straight stitching.
Remove the throat plate.
Set the needle to the lowest position.
Raise the needle gradually while turning the actuator. In this case, the tip of the hook should go 1.5 mm above the hole in the needle. The distance between the tip of the needle and the tip of the shuttle should be 0.175 mm on average. These settings are set using the pericellular screw.

On older devices - "PMZ", "Podolsk" and "Chaika", the same calibration is performed in the zigzag stitching mode. In this case, the distance between the needle hole and the shuttle tip is revealed by the left and right passage of the needle through the fabric.

More precisely, the following methodology for eliminating the same malfunction will help you navigate.

Malfunction	What should be done
The thread is too loose or too tightly wound around the bobbin. The tension should be checked manually or by means of a test seam.	Make sure the bobbin is inserted correctly. Readjust the tension with the screw near or within the hook.
The needle bar moved to the side while sewing.	Check that the upper thread is not overtightened.
The hook moves with a noticeable effort, some stitches on the seam are missing, the thread from below is not always caught.	Clean the shuttle from thread scrapings that impede its movement.
The fabric is being pulled into the space (under the panel), causing the shuttle to frequently jam.	Change a blunt and / or bent needle. It cannot quickly pierce matter.
Loose stitches on the back of the stitch. The shuttle does not work well.	Replace defective hook parts. It often gets stuck due to burrs, oxidation and micro cracks.

Prevention of malfunctions

Place the machine on a stable table, console or other support where the stability and level of the plane are maintained.
Select the appropriate needle and thread for the fabric to be sewn. Insert and fix the needle securely.
Thread the spools of thread according to the instructions. Do not interfere with the threading sequence. For example, the upper thread first passes through the tensioner and then through the lower thread guide (to the needle bar) - not vice versa. Also place the bobbin correctly in the hook section.
Leave a 15 cm “tail” of both strands, pull them to the side. This is necessary for a qualitative start and continuation of the seam.
Plug in the clipper, insert the test patch and try to sew. It should be flat and without any slack on the back of the loops.
Use thread that is smooth and elastic. Too fluffy and twisted over time will simply grind off the eye of the needle, make it more "broken", and the needle will break faster.
The machine has a development (run-out) of the mechanism until the next lubrication. The instructions indicate, for example, an interval of 5000 hours. Electronic machines can be equipped with a "timer" function that monitors the total running time of the motor and drive. It replaces the electromechanical analogue of engine hours (or the prototype of a tape-recorder roller meter), which could have been used in old typewriters of the 20th century. Do not ignore the specified regularity of cleaning and lubrication - pay attention to this.