The situation when a sewing machine loops from below is familiar to many users, from novice needlewomen to experienced tailors. Instead of an even, neat stitch, tangled balls form on the wrong side of the product, which not only spoil the appearance of the work, but can also cause fabric jams or needle breakage. This problem often occurs suddenly and confuses those who are accustomed to stable operation of the equipment.
The reasons for the occurrence of loops can be trivial, for example, incorrectly threaded thread, or more complex, associated with wear of mechanism parts. Understanding how the upper and lower threads interact is key to a quick diagnosis. Thread tension - this is a balance, the violation of which in any direction leads to stitching defects, so there is no need to panic, since in most cases the fault can be corrected independently.
In this article we will analyze in detail the algorithm of actions that will help you return your equipment to working capacity. We'll look at tension settings, needle condition, bobbin placement, and other critical factors. By following step-by-step instructions, you can identify and eliminate the cause of loops, saving time on a trip to the workshop.
Checking the quality of upper threading
The first thing to do if the machine starts looping is to re-thread the upper thread as carefully as possible. Often the reason lies in the fact that the thread simply did not get between the disks tension regulator. If the thread is passed past the tensioner, it falls freely down, and when the needle is lowered, excess material is formed, which is pulled to the wrong side.
Raise the presser foot before threading, as it is in this position that the tension dials are released and the thread lies correctly. Pull the thread through all the guides, making sure that it does not get stuck or twisted anywhere. Pay special attention to the thread take-up lever: the thread must pass through its eye or guide hook, otherwise feed mechanism will not pick up excess thread.
⚠️ Attention: Never start sewing without lowering your foot. If the presser foot is raised, the tension discs are released and the top thread will not be taut, which is guaranteed to create loops on the underside of the fabric.
Check to see if the thread unwinds freely from the spool. If the spool is tight or the thread has snags, this creates uneven tension. Use special spool holders to ensure smooth media feeding. Sometimes the problem is solved by simply replacing the spool with another one where the thread is wound with better quality.
Diagnostics of bobbin case and bobbin thread
If everything is in order with the upper thread, we move on to the lower part of the mechanism. The bobbin case is the heart of the lower unit, and the slightest error in its installation or condition will result in stitching defects. Remove the cap from the shuttle and inspect it for damage, cracks, or deformation of the tension spring.
Insert the bobbin into the cap strictly in the direction indicated on the diagram inside the machine body or on the cap itself. The thread should pass under the spring plate and fall into the slot with a characteristic click. If the thread is inserted incorrectly, bobbin thread tension will be completely absent, and it will be pulled upward uncontrollably.
- 🧵 Check if there is any lint or a piece of thread stuck under the bobbin case tension spring, as this will interfere with the normal movement of the thread.
- 🔄 Make sure the bobbin rotates in the correct direction when pulling the thread (usually counterclockwise for a horizontal hook).
- 🔍 Inspect the bobbin itself: if its edges have burrs or it is deformed, the thread will cling and break, creating loops.
Clean the shuttle device from dust and fabric fuzz. Accumulated lint can block the movement of the thread or prevent the parts from fitting tightly. Use a soft brush or a special brush for cleaning. After cleaning, be sure to drop a drop of oil into the friction points, if this is provided in the instructions for your model.
☑️ Diagnostics of the bobbin unit
Adjusting thread tension
Adjusting the balance between the top and bobbin threads is the most delicate aspect of eliminating loops. If the machine loops at the bottom, this often means that the top thread is too loose, or, conversely, the bottom thread is too loose (although the latter is less common). Adjustment is made using a screw on the bobbin case and a regulator on the machine body.
First, try changing the position of the upper thread regulator. Turn the wheel to a higher value (for example, from 4 to 5 or 6) to increase the tension. Make a test stitch on a piece of fabric. If the loops become smaller but do not disappear completely, continue to gradually increase the tension. Do not turn the regulator sharply, it is better to do it step by step.
| Symptom | Reason | Action |
|---|---|---|
| Loops at the bottom, top thread visible on the wrong side | Weak upper thread tension | Increase the value on the upper thread regulator |
| Loops on top, bottom thread visible on face | Weak bobbin thread tension | Tighten the screw on the bobbin case |
| The fabric is gathered into an accordion | Both threads are too tight | Release tension and check stitch length |
| The thread breaks when sewing | Constriction or burrs on the needle | Loosen the tension, replace the needle |
If adjusting the top assembly does not help, you can carefully tighten the small screw on the bobbin case spring. Do this very carefully, literally a quarter turn, and check the result each time. Remember the original position of the screwso that in case of failure you can return everything as it was. Often the problem is solved by thoroughly cleaning the area under this screw, rather than by adjusting it.
Influence of needle condition on loop formation
The needle is a consumable item that takes on the load first. A dull, bent or simply incorrectly installed needle will inevitably cause your sewing machine to start looping. When the needle point is dull, it does not pierce the fabric cleanly, but pushes the thread inward, creating an extra loop that the shuttle cannot properly grip.
Check the installation of the needle: it should be inserted all the way into the needle holder with the flat side (flat) in the correct direction indicated in the instructions. For most home machines, the flat faces toward the rear or to the right, but there are models where the orientation is different. If the needle is not inserted all the way, the timing (synchronization) of the meeting of the needle and the shuttle is disrupted.
- 📏 Choose the correct needle size for the thickness of the fabric: for thin fabrics No. 70-80, for jeans No. 90-110.
- 🛑 Replace the needle if you have already sewn several projects or accidentally touched a pin.
- ✨ Use special needles (e.g. Jersey for knitwear or Jeans for denim), since the shape of the point affects the formation of the loop.
Pay attention to the quality of the needle itself. Cheap needles may have microscopic burrs on the eye or point, which injure the thread and interfere with its sliding. Use needles from trusted brands such as Schmetz, Organ or Groz-Beckert. Replacing the needle is the cheapest and often most effective solution to a loop problem.
Problems with the presser foot and fabric feed
The quality of the stitching directly depends on how tightly the foot presses the fabric to the needle plate. If the pressure of the foot is too weak, the tissue rises along with it during the puncture with the needle. At this point, the top thread is pulled out excessively, and when the needle is lowered, this excess goes to the wrong side, forming a loop.
Check whether the presser foot lever is lowered. Sometimes users forget to put it down after threading or cleaning the machine. Also make sure that the tab itself is intact, has no play and is installed correctly. For thick fabrics (jeans, coat fabric), the pressure needs to be increased, for thin fabrics (silk, chiffon) - reduced, but not allowing a complete lack of pressure.
Examine the needle plate. The needle hole should not be too wide for the selected thread and fabric. If you sew thin fabric on a plate with a wide opening (designed for zigzag or thick threads), the fabric may be pulled into the opening, disrupting the looping process. In such cases, use a special straight plate or place a strip of paper under the seam.
⚠️ Attention: Do not pull the fabric with your hands either from the front or back while sewing. The machine itself advances the material using a rack. Manual tension disrupts thread balance and is a common cause of loops and needle breakage.
Synchronization of mechanisms and other reasons
If all of the above methods did not help, perhaps the problem lies in the synchronization of the needle and the shuttle. The nose of the shuttle must pass the needle at a strictly defined moment when the needle begins to rise, forming a loop. If this timing is disrupted (for example, after the needle hits the metal or the machine falls), the shuttle will miss or catch too much thread.
Check if the shaft or other visible parts of the mechanism are bent. Sometimes a foreign object (a paperclip, a button) can get inside, which blocks the free movement of the thread or the movement of parts. Turn the flywheel manually (by yourself!) and listen: the movement should be smooth, without knocking or jamming.
In some cases, the cause is the quality of the threads. Old, dry threads lose their elasticity and strength, they can tear or lie unevenly. Also, you should not use threads that are not intended for sewing machines (for example, pure cotton without lubricant for high-speed machines), as they create a lot of friction.
Why does the machine loop only on certain fabrics?
Different fabrics require different settings. On slippery fabrics (satin, raincoat), the thread may slip if the presser foot is pressed weakly. On knitwear you need a special needle, otherwise the fabric will tighten. Always test the settings on a scrap of the exact fabric you will be sewing from.
Is it possible to use the machine if it loops a little?
Highly not recommended. The constant formation of loops leads to tangling of the thread in the hook, which can jam the mechanism, break the needle, or even lead to breakage of the bobbin case. In addition, the seam will be fragile and unaesthetic.
How often should you lubricate the machine to avoid problems?
Modern household machines often have factory lubricant for a long time, but if you sew a lot, you need to lubricate the rubbing parts (hook, shafts) with special oil once every 6-12 months. Don't use regular sunflower oil - it dries out and turns into glue.
What should I do if the thread constantly breaks when trying to adjust the tension?
This is a sign that the tension is already too strong for the thread, or the thread is of poor quality. Try loosening the top adjuster, changing the thread to a stronger one, or increasing the needle number. Also check if there are any burrs in the thread path.