With the development of social economy and the improvement of people’s living standards, people are more and more pursuing personalization, so many people will buy home sewing machines to make clothes at home, but problems will inevitably occur after using the sewing machines for a period of time. So what should I do if the sewing machine breaks or jumps the thread? What is the reason for the broken needle of the sewing machine? Let’s share the common sewing machine fault repair methods for you, let’s take a look.
How to use the sewing machine correctly
For those who are new to sewing machines, it is not easy to drive a straight line. Don’t panic and run, it’s normal, just like when we held the mouse for the first time, it didn’t run around the screen indiscriminately. Practice makes perfect, you need to master the basic skills and practice more.
1. Thread the needle correctly (wrong thread will cause the bottom to be tangled);
2. Install the bobbin correctly;
3. Turn on the power, Start sewing.
Notes: The presser foot needs to be raised for threading to ensure the quality of the thread. Before starting sewing, turn the handwheel to check whether the needle will hit the presser foot or the needle plate. Insert the needle into the fabric to start sewing.
Sewing material failure
1. Sewing material wrinkling
Analysis: Needle Broken tip, excessive bottom thread tension, improper adjustment of differential mechanism. Treatment method: replace the needle with a new one, loosen the screw of the bobbin spring, and readjust the differential mechanism.
2. The bottom of the sewing material is “gnawed” to form a grid tooth mark
Analysis: The feeding teeth are too sharp and the pressure of the presser foot is too high. Treatment method: Use oilstone to grind the tip of the feeding tooth and loosen the pressure adjusting screw of the presser foot.
3. There is a thread under the sewing material, and there is a sound of breaking the fiber when sewing.
Analysis: The needle is broken or too blunt. Treatment method: Replace the needle with a new one.
4. The sewing material is stagnant
Analysis: The feed dog is too low and the presser foot pressure is too high. Treatment method: Raise the feed dog and tighten the pressure adjusting screw.
5. The sewing material goes back and forth
Analysis: The feed dog is too high. Treatment method: adjust the feed dog.
6. The sewing material cannot be sewn backwards
Analysis: The feed cam shifts. Solution: Adjust the position of the feed cam.
7. The sewing material runs obliquely irregularly
Analysis: The feed dog is installed crookedly or the feed dog screw is loose. Treatment method: correct the feed dog and tighten the feed dog screw.
Operational failures
1. Machine head rotation stagnation
Analysis: added wrong Lubricating oil, especially filled with vegetable oil; too much dirt in shuttle bed; connecting rod screws and conical screws are too tight.
Treatment method: after flushing with kerosene, refill the sewing machine oil; clean the shuttle bed; loosen the screw to ensure its clearance.
2. Half-circle stagnant, half-circle slippery, or a stagnant point per revolution
Analysis: Shuttle bed inner wheel There is a thread head, which is not only half-stagnant during operation, but also accompanied by violent shaking and noise; the position of the feed dog is too high or the dirt accumulates in the gap between the teeth, so that the feed dog collides with the needle plate when it rises.
Treatment method: clean the shuttle bed and add a little sewing oil; clean or lower the feed dog; replace or straighten the needle bar.
3. The machine head is stuck and cannot move
Analysis: The position of the feed dog is too far forward or too far back, and the needle plate is touched; the needle bar The installation position is too high, and the needle clip touches the casing.
Processing method: adjust the position of the feed dog, re-align the needle, and adjust the height of the needle bar.
4. The noise comes from the needle mechanism
Analysis: The needle bar, needle bar sleeve, small connecting rod and other wear and tear are too large; the small connecting rod screw , Needle bar crank screw is loose.
Treatment method: replace the new needle bar, needle bar cover, small connecting rod and other accessories; re-tighten the small connecting rod screw and the needle bar crank screw loose.
5. The noise comes from the feeding mechanism
Analysis: the large pointed conical screw is worn or loose, the feeding dog touches the needle plate, and the stitch length adjusting mechanism is loose.
Treatment method: Grind or re-adjust the large pointed conical screw, re-adjust the feed dog touch plate, re-adjust or tighten the stitch adjustment mechanism screw.
6. The noise comes from the shuttle mechanism
Analysis: The wear of the shuttle and the shuttle bed causes a large gap, and the gap between the shuttle and the shuttle carrier is too large. large and impactful.
Treatment method: Replace with new shuttle and shuttle bed, etc., adjust the spacing or replace with new shuttle and shuttle holder.
7. General noise
Analysis: The upper shaft, lower shaft and bushing are worn, causing the upper and lower shafts to move; or the machine lacks oil.
Treatment method: replace the new upper shaft, lower shaft and shaft sleeve, or adjust the clearance between the upper and lower shaft planes, pay attention to maintenance, and add lubricating oil on time.
Trouble in stitching
1, the upper thread is floating
Analysis: Thread tensioner pressure too low. Treatment method: Tighten the clamping thread and increase the tension of the cotton thread.
2. The bottom thread is floating
Analysis: The bobbin spring is too loose. Treatment method: Tighten the bobbin spring screw to increase the tension of the bottom thread.
3. The stitch length is long and short
Analysis: The pressure of the presser foot is too small. Treatment method: Tighten the pressure regulating screw.
4. Each stitch below the sewing material has a thread cover appearing in the form of a towel thread cover
Analysis: The action of cloth feeding and thread take-up is inconsistent. Treatment method: Adjust the feeding cam screw so that the feeding and thread take-up actions are in harmony.
Needle breakage of sewing machine
1. Needle broken for sewing thick material
Analysis: Needle Too thin or bent, uneven thickness of the sewing material, and excessive movement of the needle bar.
Treatment method: change a new thick needle, adapt to slow down the sewing speed and help feed the material by hand, change a new needle bar or needle bar cover.
2. Continuous needles with short stitches and broken needles with long stitches
Analysis: lag in the action of the feed dogs, unqualified feed dogs, and needles The needle is broken by touching the rear end of the feed dog.
Treatment method: Adjust the positioning of the feed cam, shorten the needle distance appropriately or replace the feed dog with a new one.
3. The needle is broken under the needle plate
Analysis: The needle position is too low, the needle touches the shuttle, the shuttle is not installed properly, The tip of the shuttle hook touches the needle, the clearance between the shuttle holder and the needle end is too small or too large, and the shuttle holder touches the needle or loses the needle protection function.
Treatment method: adjust the position of the needle bar or needle, re-install the shuttle, and adjust the clearance between the shuttle holder and the needle.
4. The needle is broken on the needle plate
Analysis: The sewing material is pulled too hard by hand, causing the needle to bend and the presser foot screw to loosen, causing the The presser foot slants and touches the needle, and the displacement of the feeding cam causes the sewing material to break the needle, and there is a hard object in the sewing material that causes the needle to break.
Processing method: strengthen the operation practice, adjust the presser foot to tighten the screw, and adjust the position of the feed cam screw.
Sewing machine thread breakage fault
1. The first needle is broken, and the broken thread ends in a cut shape.
Analysis: The needle is installed backwards or the needle is not installed enough, resulting in the needle being too low. The sewing material is too hard, the needle is too thin or the pressure of the presser foot is too high.
Treatment method: Check the installation of the needle and whether the screw of the connecting shaft of the needle bar is loose. Change the needle or adjust the presser foot pressure.
2. The suture is curled at both ends of the broken end, and has short whiskers.
Analysis: The thread is too tight or the thread is tangled during sewing. The thread is squeezed into the shuttle bed guide groove by the shuttle. The suture is brittle and easy to knot, the quality is poor, and there are burrs at the thread-passing part.
Treatment method: Change the pressure of the wire clamp and check the wire passing line to eliminate the entanglement. Check the wear of the shuttle and replace the shuttle if necessary. Sand the area over the thread and replace the suture.
3. The lower part of the sewing material has a heavy thread, and the thread cannot be broken due to the inability to form the stitch length.
Analysis: The feed dog is too low, and the sewing material does not stop, and the accumulated line is too much and breaks. The cloth feeding and the thread are out of step and are cut off. The presser foot and needle are loose, preventing the sewing material from running.
Treatment method: Raise the feed dog, adjust the positioning angle of the feed cam, and tighten the presser foot and needle screw.
4. The thread is suddenly broken during sewing, and the upper thread has curved fluctuations.
Analysis: The needle thread is not installed on the shuttle bed and the needle thread is inserted into the shuttle bed. The bobbin case does not lock tightly or suddenly shifts during sewing. The quality of the shuttle is poor. The shuttle center spring is too long or the center sleeve is oval.
Treatment method: re-adjust the shuttle bed position, re-install the shuttle, and replace the shuttle with the center sleeve.
5. The bottom thread is suddenly broken during sewing. The bobbin sleeve is unqualified, and the inner diameter is elliptical.
Analysis: The bobbin sleeve is unqualified, and the inner diameter is elliptical, causing the bobbin to fail to rotate. The bobbin spring screw is overtightened and the bobbin case pressure is too low. The bobbin winding is too full or too loose and messy. The bottom thread is brittle and has knots, so that the bottom core cannot pass through the bobbin spring.
Treatment method: replace the bobbin case, loosen the bobbin spring screw, rewind the bobbin thread, and replace the lower thread.
Sewing machine jumper fault
1. The lower thread cannot be drawn.
Analysis: The bobbin thread is too short, the bobbin thread is caught in the shuttle door, the needle is too high, and the bobbin cannot hook the thread loop.
Treatment method: Lengthen the hook thread, check whether the lower thread is stuck, and remove it. Needle bar connecting shaft firm screw loosens the needle bar and moves up, the needle bar should be lowered, re-align the needle, and tighten the fastening screw.
2. The needle bar moves.
Analysis: Needle bar hole, needle bar wear, needle bar connecting screw loose, needle bar displacement.
Treatment method: replace the needle bar cover, or select a new needle bar, re-align the needle; and tighten the set screw.
3. Skip a stitch after a few stitches.
Analysis: Worn shuttle, blunt tip, needle too high or too low.
Processing method: change the shuttle, adjust the height of the needle bar or the needle, and re-align the needle.
4. Continuous jumper or one stitch cannot be sewn.
Analysis: Poor quality needles or bent needles cannot properly produce loops. The needle is too high to hook the thread loop, and the three needles of the sewing material and stitching are improperly matched. Long-term use of shuttle, swing bed and other parts are seriously worn or broken.
Treatment method: replace the qualified needle or straighten the needle. Adjust the needle bar or needle height. Under normal circumstances, the shuttle or shuttle bed can be replaced and overhauled if necessary.
5. No jumpers for thin seams, but jumpers for thick seams.
Analysis: The presser foot pressure is not enough, the needle is too thin, the thread hooking mechanism and other parts are seriously worn.
Treatment method: adjust the pressure of the presser foot, change the needle, replace the parts, and carry out repairs.
6. Sew thick jumpers and thin jumpers.
Analysis: The needle hole of the needle plate is too worn, the needle is too thick, the bottom of the presser foot is worn, or the presser foot pressure is too small.
Treatment method: change the needle plate, change the fine needle, change the presser foot, change the presser foot, or adjust the pressure of the presser foot.
How to maintain the sewing machine
1. Cleaning the sewing machine
(1) Feed dog For cleaning, remove the screw between the needle plate and the feed dog, remove the lint and dust, and add a small amount of sewing machine oil.
(2) Cleaning of shuttle bed Shuttle bed is the core of sewing machine work, and it is also the most prone to failure. Therefore, it is necessary to frequently remove dirt and add a small amount of sewing machine oil.
(3) Cleaning of other parts The surface of the sewing machine and all parts in the panel should be cleaned regularly.
2. Lubrication of sewing machine
Special sewing oil must be used. The sewing machine should be fully oiled after one or several days of continuous use. If oil is added between uses, the machine should be idling for a period of time to fully infiltrate the oil and throw off excess oil. Then use a clean soft cloth to clean the machine head. Clean the surface and the countertop to avoid soiling the sewing material. Then thread and sew the rags, use the movement of the sewing thread to clean them, and throw out the excess oil stains until there is no oil stains on the rags, and then proceed to formal sewing.
3. Secondly, the following points should be paid attention to when maintaining the sewing machine:
(1) After the work, insert the needle into the needle hole plate, Raise the presser foot and cover the machine head with a hood to prevent dust dust from entering.
(2) When starting to work, first check the main parts, how heavy the pedal is, whether there is any special sound, whether the needle is normal, etc. If any abnormal phenomenon is found, it should be repaired in time.
(3) After the machine has been used for a long time, an overhaul should be carried out.
