The situation where the long-awaited sewing-machine refuses to form a smooth seam, is able to knock out even an experienced master. Instead of beautiful stitches, you see a tangle of threads, gaps or a characteristic crackling mechanism. Panic in this case is not worth it, because in 90% of cases the problem lies in the wrong filling or dulled needle.
Before carrying equipment to the service center, it is necessary to conduct a thorough examination. diagnostics. Often the reason lies in the elementary things that can be fixed in a few minutes without special tools. Ignoring the first signs of malfunction can lead to more serious breakdowns of the tissue supply mechanism or shuttle-knot.
In this article, we will explain in detail why sewing-machine stopped sewing, how to eliminate the gaps of stitches and what to do if the thread is constantly entangled. You will learn how to adjust the tension correctly and when it is really time to change the needle. A critical mistake that 8 out of 10 beginners make is trying to sew too thick a fabric on a thin needle, which instantly knocks down the settings of the mechanism.
Diagnosis of the main causes of missing stitches
If you sewing-machine skip stitches, the first thing you need to check the condition of the needle. Even the microscopic bending of the tip, invisible to the eye, is able to shift the moment of capture of the thread by the nose of the shuttle. Needles are consumables and their regular replacement is part of basic maintenance.
The second important aspect is the matching of the needle type and the tissue. Knitting requires needles with rounded tips (type) Jersey or Stretch), and for jeans - reinforced versions with markings Denim. The use of a universal needle on complex materials often leads to the fact that the mechanism simply does not have time to form a loop.
The third factor is the quality of the threads. Cheap filaments with uneven torsion can get stuck in the needle’s ear or create excessive friction. Tension. The upper thread in this case becomes uncontrollable, which leads to gaps.
- 🧵 Check the correct needle installation: the flat side should look strictly backward (or according to the instructions for your model). Pfaff or Brother).
- 🔍 Examine the needle's point under magnification for chipping and blunting.
- 🧶 Make sure the needle number matches the tissue density (e.g., No. 90 for medium-sized tissues).
Problems with the lower thread and the shuttle mechanism
When sewing-machine does not make a line and collects a "beard" of threads from below, the problem almost always lies in the wrong filling of the lower nitrogen. Many users simply insert a spooler cap, forgetting to stretch the thread through a special spring plate.
Inside the shuttle passage, pile, dust and trimmings of threads often accumulate. This "feel" disrupts the free rotation of the spools cap, creating uneven tension. Regular brushing is a mandatory procedure after each large project.
⚠️ Warning: Never pull the lower thread with your hands while the machine is running. This can lead to deformation of the tensioner spring and disruption of the synchronization of the needle and shuttle.
It is also worth checking the spools cap itself. If it has cracks or burrs on the metal part, the thread will break or get tangled. For a vertical shuttle, it is important to properly set the cap to the characteristic click.
- 🌀 Blow the shuttle mechanism with compressed air or thoroughly clean with a soft brush.
- 🔩 Check the tension adjustment screw of the lower thread: it should not be too tight or completely weakened.
- 🛑 Make sure that the spooler cap is inserted into the guides to the point.
Tightening of the threads: balance of upper and lower
The quality of the line depends on a balanced tension thread. If the nodule of the connection of threads goes to the front side of the tissue, then the tension of the upper thread is too weak. If the nodules are visible from below, the problem is in the upper tensioner or too strong lower.
Adjustment is made using a disk regulator located on the front panel of the machine. The numbers on the regulator indicate the force of pressing the thread. For standard fabrics, a range of 4 to 6 is usually used. However, for thin silk or tight jeans settings Janome or AstraLux I'll have to change.
Before changing the tension settings, take a picture of the current position of the regulator on the phone. This will allow you to quickly return to the original parameters if the experiment fails.
In the raised position, the nitrogen rulers are compressed, and the setting will be incorrect. After each change in the position of the regulator, make several test stitches on a patch of the same fabric.
| Symptoms. | Top thread | Understring | Action. |
|---|---|---|---|
| Nodules on top | Weak. | Normal. | Increase the tension of the top |
| Nodules from below | Strong. | Normal. | Reduce the tension of the top |
| Loops on both sides | Weak. | Weak. | Check the filling of both threads |
| Cloth collects | Very strong. | Very strong. | Weaken both tensioners. |
The effect of the needle and its correct installation
A misplaced needle is the number one reason why sewing-machine He refuses to sew. The needle should be inserted into the needle holder to the point. If it is not completed, the nose of the shuttle simply does not get into the thread loop at the right time.
The orientation of the needle is also critical. Most household cars (Singer, Brother) the flat side of the bulb shall look backward. In some industrial or specialized models (Juki) the rules may differ. Always check the instructions.
☑️ Verification of needle installation
The needle can bend not only from bad tissue, but also from a sharp pulling of tissue from under the paw. Always turn the fabric with the needle lowered or use the fabric rotation function. This will save the mechanism from shock loads.
- 📏 Change the needle after each major project or after 8 hours of continuous operation.
- 🚫 Do not use rusty or bent needles, they spoil the fabric and mechanism.
- 🔧 Tighten the screw of the needle attachment with the key coming in the kit, not with your fingers.
Mechanical malfunctions and wear of parts
If all the settings are correct, but sewing-machine still does not form a line, perhaps there was a failure of synchronization or wear of parts. A common problem is the knocked-down phases of the shaft rotation. This happens if the user twisted the wheel in the opposite direction when the thread is stuck.
Wear of the teeth of the slats of tissue promotion also affects the quality of the seam. If the fabric does not move or moves in jerks, the stitch will be uneven. In such cases, it may be necessary to replace the rack or adjust its height.
⚠️ Warning: If you hear a metal thud or a gnashing as the flywheel spins, stop working immediately. Further operation will lead to the destruction of the gears of the drive.
How to check the shuttle synchronization?
To check, remove the needle plate and slowly rotate the flywheel. At the moment when the needle falls to the lower position, the nose of the shuttle should pass exactly above the needle's eye (at a distance of 1-2 mm). If the gap is greater or less, adjustment by the master is required.
It is also worth checking the drive belt. If it stretched or jumped off, the motor will work, and the needle driver will stay in place or move with a small amplitude. Direct-drive vehicles (Direct Drive) the problem may be electronics.
Specificity of working with different types of tissues
Sometimes. sewing-machine It is functional, but cannot handle a specific fabric. Thin knitwear requires the use of a special foot and a needle with a rounded tip so as not to damage the fibers. A tight jean, on the other hand, needs a powerful puncture and slow speed.
Slippery fabrics (silk, satin) can be tightened into the shuttle mechanism. In this case, it helps to put a strip of paper under the seam. After stitching, the paper is easily torn off, and the fabric remains intact.
The main secret of working with complex fabrics is not to pull or push the material with your hands. Let the reiki teeth themselves promote the tissue, your task is only to direct it.
For knitted canvases, it is important to use elastic threads and not to drag the line, otherwise the seam will burst when stretched. Customizing the differential (if it is in your model) will help avoid stretching the edge of the fabric.
- 👖 For jeans, use needles No. 100-110 and thread No. 40.
- 👕 For knitting, needles of the type are required Stretch And a knitwear leg.
- 🎗️ For the skin, special needles with a wedge-shaped tip and a Teflon foot are needed.
Frequent questions about sewing machine repair
Why does a sewing machine hum but not sew?
This may indicate a thread jamming mechanism, lack of lubrication or a problem with the drive belt. Check the shuttle for debris and try to turn the flywheel with your hand. If it is not rotating, disassemble and clean.
How often should I change the needle in the sewing machine?
It is recommended that you change the needle before each new project or after 8-10 hours of work. A dulled needle spoils the fabric and can damage the shuttle.
Can I lubricate a sewing machine with ordinary oil?
No, use only special oil for sewing machines. Ordinary machine or vegetable oil thickens over time, turns into resin and jams the mechanism dead.
What to do if the car breaks the thread?
Check the quality of the threads, the correctness of refilling, the condition of the needle (burrows on the ear) and tension. Often the thread breaks against the burrs on a needle plate or a spooly cap.