How a sewing machine works. Animagraffs
Choosing the type of shuttle for your sewing machine
The sewing shuttle is one of the essential controls of a two-strand sewing machine. Among the modern models there are three basic types: vertical double whip, horizontal and pendulum. Strictly speaking, the type of shuttle. not the only criteria for choosing a new device, but this is one of the indicators that determine the scope of the machine, its capabilities, the potential. Let’s analyze the features of each type of shuttle and find out which of them cope better with their duties in the sewing machine.
How are the sewing shuttles
The sewing shuttle for any sewing machine. is the most important element of any sewing machine. The condition and adjustment of the interaction of the needle with the hook spout determines the quality of the machine. This parameter affects the absence of skips in the stitch, thread breakage. Its surface must be in perfect condition and free from roughness, dents, rust, etc.
The loop, caught by the sewing hook spout from the needle, is expanded by its walls, comes off at a certain point, and is pulled back into the stitching. Any nicks or rust spots can affect thread slip, and as a result, a “looping” of the thread in the stitch and even a breakage of the upper thread is possible.
Sewing machines differ from each other not only in the presence of certain operations and functions, but also the type of sewing shuttle. The hook can be horizontal (2); vertical (3) or swing type (1). And before you buy a sewing machine, be sure to decide which sewing shuttle option is right for you.
Thread tension
This manipulation is carried out with a special screw, located above the needle holder. The tension of the upper thread is an important indicator, controlling the quality of the seam. Not far from the needle holder there is a special ear that moves in the process and does not allow the thread to slacken or sag when the needle goes up. Without this small detail all the work of the sewing machine would be null and void.
How to properly install and adjust?
Sewing machine adjustments are an important step in making a garment. If everything is done correctly, the product will be flawlessly beautiful, besides the perfect adjustment of the equipment has a positive impact on its future performance.
Included with the machine manufacturer provides the user with an instruction manual, which describes in detail, step by step, the steps to set up and prepare the sewing machine for work.
- align the machine horizontally;
- lower the needle to the maximum;
- connect the end of the hook and the middle of the needle;
- fix the screws and secure the needle bar.
Important! The distance between the hook and needle must be exactly as specified by the manufacturer.
Otherwise, sewing quality problems may arise, namely:
While the needle is raised, a loop of upper thread is formed. at this time, the hook should pass as close to the needle plate as possible.
the recommended value is 0.16 mm, but no more than 0.5 mm. Figures vary depending on the type of material used.
Setting up the equipment is divided into preventive in the operation of equipment and “repair” if any malfunctions occur.
- remove the needle plate;
- clean the hook from dirt;
- set the desired distance between the needle and the shuttle;
- adjust the stitch length;
- check the tightness of the screws and adjusting screws;
- visually inspect the condition of the needle;
- Grease the ribs with a special grease (paste).
Additional measures (you should put the sewing machine on its side):
- check the running gears for grease;
- Check the sharpness of the spout;
- Check the fins and heel for dirt and corrosion.
How to check the hook for grease:
- Remove the needle plate and the sewing machine foot
- Place a sheet of white paper on the table
- Start the machine at maximum speed.
If there are vertical stripes on a sheet of paper, it means that there is enough grease. Lack of them indicates a lack of lubrication, which can lead to equipment failure.
Maybe the bobbin is misaligned. Needle plate must be removed, bobbin mechanism pulled out and placed in the correct position
The hook does not pick up the thread, the needle does not form a loop. The cause is the wrong distance between the hook and the needle. Most likely it is less than 0.1 mm.
The needle itself may be the cause. It may have been blunted by banging on a button, plate. Check and change it.
How does a sewing machine work?
The problem occurred through improper and inattentive installation of the needle. You need to loosen the needle and insert it as far as it will go.
Needle bar and tensioner attachment
The most common cause of sewing machine malfunction is the upper thread. Thread breaks, loops in the stitch, irregular stitching, skips, etc.д. This often depends on the upper thread tensioner. It is the fastening of the tensioner (Chaika) that most often causes the tensioner to work badly. The plastic housing is squeezed by the pressure of the screw, and over time the tensioner starts to wobble, or even “falls out” of the housing altogether.
The arrows on this photo show the fasteners of the needle bar and tensioner. Sewing rougher fabrics, leather seams, and especially hemming jeans, the needle bar can move up with the needle. Slightly loosen the screw and adjust its position, make sure that the blade and needle groove have the correct position in relation to the shuttle (not turned to the left or right). For details on how to disassemble and reassemble the tensioner sewing machine see article “Device of tensioner sewing machine Chayka”.
Horizontal shuttle
This is a modern product, which is installed on the latest generation of sewing machines. The bobbin and thread are inserted into the holder, and it is not necessary to remove the entire system. It runs horizontally. Advantages of this product:
- Convenient operation. Can quickly tuck in a thread and check the balance of the thread in the spool, because the body is designed with a transparent version.
- No noise and vibration. The bobbin rotates smoothly and does not produce any noise.
- High sewing speed. This is why these types of shuttles are often used on an industrial scale.
- Easy maintenance. The product does not need constant lubrication, it works without lubrication.
- Simple design. That’s why the threads get tangled much less often in this shuttle. Usually provided that the body appeared nicks that catch the thread, interfering with the established course of work.
Naturally, there are also disadvantages. Because they are made of plastic, they will last less time than metal products. Therefore, a serious industrial company prefers vertical shuttles, made of metal. There are also difficulties with adjusting the thread tension, because you need to remove the needle plate for this.
Sewing machine bobbin
The sewing machine‘s needle is an essential control for double-stranded versions of the sewing machine. The quality of the functioning of the device depends not only on its condition, but also on the setting of its interaction with the needle.
No skipped stitches in the stitching, no signs of thread looping at the bottom, thread breaks above and below, and many other features of quality machine stitching are indicative of this issue.
If you do notice these defects or other malfunctions, then you should call a master repairman, who in addition to repair, adjustment and adjustment will hold a master class for beginners on how to use the equipment, insert the bobbin, etc.
The quilting device.
Quilting devices have the most complex design compared to other working organs in sewing machines. Bobbin device is necessary for capturing the needle loop and carry through its thread from the bobbin.
The most common in sewing machines shuttles with evenly rotating horizontal axis and evenly rotating vertical axis.
In horizontal rotating shuttles, the bobbin case and bobbin case are held from rotation by a set pin, which enters the slot in the bobbin case. The presence of a guaranteed gap between the set pin protrusion and the bobbin case groove allows the needle thread to pass unhindered around the bobbin case.
The bobbin case holds the bobbin. By adjusting the plate spring tension, it can change the hook thread tension.
Consider the design of a uniformly rotating with a horizontal axis of rotation shuttle set (Fig. 4.5). With screws 10 (two or three) body 13 The hook gear is attached to the hookshaft of the machine (Fig. 3.7 not shown).
Housing 13 has a nose 9 For gripping the needle loop. Nosey 9 Must be sharp and burrfree when operating the machine. On the housing 13 the unit is screwed 12 The top plate is attached 11. The front and side surfaces of the plate 11 as well as the sides of the spout 9, must be carefully sanded and polished. In the case 13 has a groove 14. into which the belt is inserted 16 bobbin holder 18. The bobbin holder is open at the top as well as the side surfaces of the bobbin spout 18 from the body 13 half-ring-blade 15 is used, which is fastened with three screws 7 to the body of the 13. The nose 5 of the half ring-blade 15 should be polished, because it passes the needle loop when it comes out of the shuttle device.
Belt 16 of the bobbin holder 18 is open at the top. Its ends at the break on the side edges, as well as other surfaces of the parts with which the thread comes into contact during the formation of the stitch, must be polished.
The front of the bobbin case 18 has a groove 17, into which the protrusion 3 of the latch 1. If there is a bobbin 18 two slots 17 the second is used to interact with the diverter. At the top of the front of the bobbin case 18 A groove 6 is provided in which a projection 5 of the adjusting pin is inserted 21. Setting pin 21 is fastened in the machine housing with a screw 20. In the center of the bobbin case 18 there is a center pin 19 for basing and fixing the bobbin case 23.
The bobbin case has a milled groove on the front 24, which includes a latch 3. The latch 3 is hinged (with a pin 30) is connected to the movable plate 2. The latch 3 (to prevent it from falling out of the bobbin case) has a screw 4. The latch 3 is secured in the groove on the stud bolt 19 With a spring 31, which is mounted in the hole 29 of the bobbin case. Spring 28 to regulate the tension of the hook thread is secured by a setting 26 and adjusting 27 screws on the side of the housing 23 cap.
Alex Askaroff Presents a shuttle sewing machine.
Bobbin 22 is put on a cylindrical hollow shaft 25 of the bobbin case 23. To reduce inertial unwinding of the thread from the bobbin 22 inside the bobbin case 23 the plate arc-shaped spring is fastened with a screw.
The quality of design and proper operation of the shuttle device largely prevents breakage of the needle thread. The greater the dimensions of the bobbin holder of the hook, the more the needle thread is pulled by the hook, the greater the likelihood of thread breaks from fraying and loss of productivity from needle thread changes. But the large dimensions of the shuttle device, allow you to produce a larger bobbin capacity and thereby reduce productivity losses from the change of the bobbin.
When the machine is running, between the spring 28 and the bobbin case 23 there is a periodical accumulation of thread lint which has to be removed.
SEWING MACHINES SHUTTLE STITCH
Double-stranded shuttle stitch. Lockstitch machines are one of the most common types of sewing machines used in the manufacture of garments, not only in industry, small businesses, but also in the home. The ability to perform a variety of operations on them to assemble a variety of products allow these machines to be considered as general-purpose machines. The machine sews the parts of the product double-stranded shuttle stitch, which consists of two threads: the upper (since it is on the surface of the material) needle (tucked into the needle) and lower (as laid on the underside of the material) shuttle (comes out of the shuttle, bobbin).
The advantages of double-stranded hook stitch is the same type of stitch on the upper and lower sides of the material, its resistance to unraveling, the lack of thickening in the laying and economical thread consumption. The disadvantages of the shuttle stitch include its poor extensibility, which is especially important when sewing knitted materials, and the need for periodic change of the bobbin with a hook thread when the stitching machine. Spool change costs up to 15. 25 с.
The quality look of a two-stranded shuttle stitch is considered when the thread weave is placed in the middle between the materials being worked (fig. 4.1, а). When the needle thread comes out from below (Fig. 4.1, б) or shuttle. from above (Fig. 4.1, в) consider that the stitch is looped at the bottom or at the top.
The total consumption /Dcm) of the hook or needle thread depends on the frequency т and thickness tcm stitch in the stitching:
where L. the length of the stitch, cm; К= 0,9. 1,1. factor that takes into account the degree of tightening of the thread in the stitch; т. Stitching frequency, t.е. number of stitches per 1 cm of stitching; t(M- stitch thickness or thickness of materials to be sewn, mm.
